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Este mes en... American Journal of Transplantation

Sumarios de Revistas

Este mes en... American Journal of Transplantation:

  • Belatacept Combined with Transient Calcineurin Inhibitor Therapy Prevents Rejection and Promotes Improved Long-Term Renal Allograft Function
    Belatacept, a T cell costimulation-blocker demonstrated superior renal function, lower cardiovascular risk, and improved graft/patient survival in renal transplant recipients. Despite the potential benefits, adoption of belatacept has been limited in part due to concerns regarding higher rates and grades of acute rejection in clinical trials. Since July 2011 we have utilized belatacept-based immunosuppression regimens in clinical practice. In this retrospective analysis of 745 patients undergoing renal transplantation at our center, we compared patients treated with belatacept (n=535) to a historical cohort receiving a tacrolimus-based protocol (n=205). Patient and graft survival were equivalent between all groups. An increased rate of acute rejection was observed in an initial cohort treated with a protocol similar to the low-intensity regimen from the BENEFIT trial vs the historical tacrolimus group (50.5% vs 20.5%). The addition of a transient course tacrolimus reduced rejection rates to acceptable levels (16%). Treatment with belatacept was associated with superior eGFR (belatacept 63.8ml/min vs tacrolimus 46.2ml/min at 4 years, p<0.0001). There were no differences in serious infections including rates of CMV or BK viremia. We describe the development of a costimulatory blockade-based strategy that ultimately allows renal transplant recipients to achieve CNI-free immunosuppression. This article is protected by copyright. All rights reserved.
  • Thymic-peripheral crosstalk in lymphodepletion therapy
    T cell depletion is widely used as induction therapy in solid organ transplants and particularly in kidney transplantation, to reduce the episodes of acute cellular rejection. The resultant reduction in T cell numbers is usually temporary, as T cells are actively replenished due to thymic output and/or lymphopenia-induced proliferation of remaining, depletion-resistant T cells. However, the extent of T cell replenishment and the persistence of lymphopenia varies between individuals, with potential impacts on protective or pathogenic immune responses. This article is protected by copyright. All rights reserved.
  • Breast cancer and transplantation
    Breast cancer is an important cancer among solid organ transplant recipients. While the incidence of breast cancer in solid organ transplant recipients is comparable to the age matched general population, the outcomes are generally poor. Interventions such as cancer screening which preclude the development of late stage disease through early detection are not well-studied, and clinical practice guidelines for cancer screening rely solely on recommendations from the general population. Among those with a prior breast cancer history, disease recurrence after transplantation is a rare but fearful event. Once disease recurs, the risk of death is high. The focus of this review is to present the epidemiology of breast cancer in solid organ transplant recipients, screening and preventive strategies for those who may be at risk, novel genomic profiling for determining tumor progression and the newer targeted interventions for recipients who have developed breast cancers after solid organ transplantation. This article is protected by copyright. All rights reserved.
  • Brain-dead Donors with Ornithine Transcarbamylase Deficiency: A Big Learning Opportunity in Clinical Evaluation
    We have read with interest the report by Ramanathan et al regarding a case of ornithine transcarbamylase (OTC) deficiency unmasked post–liver transplantation (1). This serves as a big learning opportunity in clinical organ donor evaluation. A consequence of this disorder is hyperammonemia. Acute high levels in serum ammonia can cause severe neurological findings such as cerebral edema and brain death (2-4). This article is protected by copyright. All rights reserved.
  • Solid renal masses in transplanted allograft kidneys: A closer look at the epidemiology and management
    The objective of this review is to explore the available literature on solid renal masses (SRM) in transplant allograft kidneys to better understand the epidemiology and management of these tumors. A literature review using PubMed was performed according to the PRISMA methodology. Fifty-six relevant studies were identified from 1988-2015. A total of 174 SRMs in 163 patients, were identified with a mean tumor size of 2.75 cm (0.5-9.0cm). Tumor histology was available in 164 (94.3%) tumors: clear cell renal cell carcinoma (RCC) (45.7%), papillary RCC (42.1%), chromophobe RCC (3%), and others (9.1%). Tumors were managed by partial nephrectomy (67.5%), radical nephrectomy (19.4%), percutaneous radiofrequency ablation (10.4%), and percutaneous cryoablation (2.4%). Of the 131 patients (80.3%) who underwent nephron-sparing interventions, 10 (7.6%) returned to dialysis and 8 (6.1%) developed tumor recurrence over a mean follow-up of 2.85 years. Of the 110 patients (67.5%) who underwent partial nephrectomy, 3.6% developed a local recurrence during a mean follow up of 3.12 years. The current management of SRMs in allograft kidneys mirrors management in the non-transplant population with notable findings including an increased rate of papillary RCC and similar recurrence rates after partial nephrectomy in the transplant population despite complex surgical anatomy. This article is protected by copyright. All rights reserved.
  • The Living Donor Collective: A Scientific Registry for Living Donors
    In the setting of an overall decline in living organ donation and new questions about long-term safety, a better understanding of outcomes after living donation has become imperative. Adequate information on outcomes important to donors may take many years to ascertain and may only be evident by comparing large numbers of donors with suitable controls. Previous studies have been unable to fully answer critical questions, primarily due to lack of appropriate controls, inadequate sample size, and/or follow-up duration too short to allow detection of important risks attributable to donation. The Organ Procurement and Transplantation Network does not follow donors long term and has no prospective control group with which to compare post-donation outcomes. There is a need to establish a national living donor registry, and to prospectively follow donors over their lifetimes. In addition, there is a need to better understand the reasons many potential donors who volunteer to donate do not donate, and whether the reasons are justified. Therefore, the US Health Resources and Services Administration asked the Scientific Registry of Transplant Recipients to establish a national registry to address these important questions. Here, we discuss the efforts, challenges, and opportunities inherent in establishing the Living Donor Collective. This article is protected by copyright. All rights reserved.
  • Potential disadvantages of over centralization of organ recovery centres: Response to Marsolais et al
    As physicians involved in the Canadian organ donation system, we read with interest the report by Marsolais et al (1). While the team at Hôpital Sacre-Coeur de Montréal deserves to be congratulated for their excellence in the organ donation, the described model has potential disadvantages, and we believe its advantages have been overstated. Marsolais et al. chose people transplanted per million (tpm) as their primary outcome, which is less frequently reported than donors per million. We disagree that tpm is the correct statistic, and we also disagree with how it was calculated. This article is protected by copyright. All rights reserved.
  • BK Virus Nephropathy Revisited
    More than 20 years after its first description and increased morbidity under powerful immunosuppression, the understanding of the pathogenesis of BK polyomavirus induced allograft nephropathy (BKVN) has changed clinical practice in renal transplantation. Screening programs were introduced at most transplant centers causing the prevalence of BKVN to decrease. However, BK viremia is still found in 10-30% of renal allograft recipients with 1-10% developing BKVN. This article is protected by copyright. All rights reserved.
  • The National Landscape of Living Kidney Donor Follow-up in the United States
    In 2013, OPTN/UNOS mandated that transplant centers collect data on living kidney donors (LKDs) at 6-months, 1-year, and 2-years post-donation, with policy-defined thresholds for the proportion of complete living donor follow-up (LDF) data submitted in a timely manner (60 days before or after the expected visit date). While mandated, it was unclear how centers across the country would perform in meeting thresholds, given potential donor and center-level challenges of LDF. To better understand the impact of this policy, we studied SRTR data for 31,615 LKDs between 1/2010-6/2015, comparing proportions of complete and timely LDF form submissions pre- and post-policy implementation. We also used multilevel logistic regression to assess donor- and center-level characteristics associated with complete and timely LDF submissions. Complete and timely 2-year LDF increased from 33% pre-policy (1/2010-1/2013) to 54% post-policy (2/2013-6/2015) (p<0.001). In an adjusted model, the odds of 2-year LDF increased by 22% per year pre-policy (p<0.001) and 23% per year post-policy (p<0.001). Despite these annual increases in LDF, only 43% (87/202) of centers met the OPTN/UNOS-required 6-month, 1-year, and 2-year LDF thresholds for LKDs who donated in 2013. These findings motivate further evaluation of LDF barriers and the optimal approaches to capturing outcomes after living donation. This article is protected by copyright. All rights reserved.
  • Report from the American society of transplantation conference on donor heart selection in adult cardiac transplantation in the U.S
    Cardiac transplantation remains the only definitive treatment for end-stage heart failure. Transplantation rates are limited by a shortage of donor hearts. This shortage is magnified because many hearts are discarded due to strict selection criteria and concern for regulatory reprimand for less than optimal post-transplant outcomes. There is no standardized approach to donor selection despite proposals to liberalize acceptance criteria. A donor heart selection conference was organized to facilitate discussion, and generate ideas for future research. The event was attended by 66 participants from 41 centers with considerable experience in cardiac donor selection. There were state-of-the-art presentations on donor selection, with subsequent break-out sessions on standardizing the process and increasing utilization of donor hearts. Participants debated misconceptions and established agreement on donor and recipient risk factors for donor selection, and identified the components necessary for a future donor risk score. Ideas for future initiatives include modification of regulatory practices to consider extended criteria donors when evaluating outcomes, and prospective studies aimed at identifying the factors leading to non-acceptance of available donor hearts. With agreement on the most important donor and recipient risk factors, it is anticipated that a consistent approach to donor selection will improve rates of heart transplantation. This article is protected by copyright. All rights reserved.
  • Modelling the iatrogenic pancreatic cancer risk after islet autotransplantation in mouse
    Iatrogenic pancreatic cancer metastasis after islet infusion is a potential risk of islet autotransplantation performed after pancreatectomy. To model this risk islets and/or pancreatic exocrine clusters obtained from a genetically engineered mouse model for pancreatic ductal adenocarcinoma (the LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre, termed KPC mouse) were transplanted via the portal vein in syngeneic wild type (WT) severely diabetic recipients in the following treatment groups: group A (n=11) received KPC exocrine clusters in volume equal to 250 equivalent islets (IEQs); group B (n=12) received 250 WT IEQs mixed with KPC exocrine clusters (1:1 volume ratio); group C (n=5) received 250 KPC IEQs and group D (n=7) received 250 wild type IEQs. The incidence of hepatic metastasis was assessed by magnetic resonance imaging and histology over the 13 months of follow-up. Overall survival was not different in the four groups. No mice developed liver metastases during the follow-up. Two mice developed spontaneous tumors: a liver hepatocellular tumor in group A and a malignant lymphoma in group D. Islets and/or exocrine clusters obtained by KPC mouse, a model which develops pancreatic cancer with 100% penetrance, do not retain the same risk of tumor development when transplanted via the portal vein in syngeneic diabetic recipient. This article is protected by copyright. All rights reserved.
  • Living Donor Liver Transplantation for Patients Older Than Age 70 Years: A Single-Center Experience
    Over the past two decades, the age of liver transplantation (LT) recipients has been increasing. We reviewed our experience with LT for patients aged 70 years or older (range: 70-78) and investigated the feasibility of performing LT, especially living donor LT (LDLT), for older patients. We retrospectively reviewed the medical records of 25 patients (15 LDLT recipients, 10 DDLT recipients), aged 70 years or older who underwent LT from January 2000 to April 2016. Their perioperative morbidity rate was 28.0% and the in-hospital mortality rate was 16.0%. This result was comparable to that of matched 60-year-old patients (n=73) (p=0.726, p=0.816). For the 70-year-old patient group, the 1- and 5-year patient survival rates were 84.0% and 69.8%, whereas the 1- and 5-year graft survival rates were 83.5% and 75.1%, respectively. Comparisons of patient and graft survival rates between matched patients 60 years old and 70 years old showed no statistically significant differences (p= 0.372, p = 0.183). Our experience suggests that patients 70 years or older should not be excluded from LT, or even LDLT, solely based on age and implies that careful selection of recipients and donors as well as meticulous surgical technique are necessary for successful results. This article is protected by copyright. All rights reserved.
  • Proteoforms in Peripheral Blood Mononuclear Cells as Novel Rejection Biomarkers in Liver Transplant Recipients
    Biomarker profiles of acute rejection in liver transplant recipients could enhance the diagnosis and management of recipients. Our aim was to identify diagnostic proteoform signatures of acute rejection in circulating immune cells, using an emergent “top down” proteomics methodology. We prepared differentially processed and cryopreserved cell lysates from 26 non-viral liver transplant recipients by molecular weight-based fractionation and analyzed them by mass spectrometry of whole proteins in three steps: 1) Nanocapillary liquid chromatography coupled with high-resolution tandem mass spectrometry; 2) database searching to identify and characterize intact proteoforms; 3) data processing through a hierarchical linear model matching the study design to quantify proteoform fold changes in patients with rejection vs. normal liver function vs. acute dysfunction without rejection. Differentially expressed proteoforms were seen in patients with rejection vs. normal and non-specific controls, most evidently in the cell preparations stored in traditional serum-rich media. Mapping analysis of these proteins back to genes through gene ontology and pathway analysis tools revealed multiple signaling pathways, including inflammation mediated by cytokines and chemokines. Larger studies are needed to validate these novel rejection signatures and test their predictive value for use in clinical management. This article is protected by copyright. All rights reserved.
  • The impact of left ventricular diastolic dysfunction on lung transplant outcome in patients with pulmonary arterial hypertension
    Diastolic dysfunction may influence perioperative outcome, early graft function and long-term survival. We compared the outcomes of DLTx for PAH patients with pre-operative LV diastolic dysfunction to those without diastolic dysfunction. Of 116 consecutive patients with PAH (who underwent transplantation between January 1995 and December 2013), 44 met our inclusion and exclusion criteria. Fourteen patients (31.8%) with diastolic dysfunction pre-LTx had a higher BMI [29 (IQR 21.5-32.6) vs. 22.4 (IRQ 19.9-25.3)], mean pulmonary arterial pressure (54.6 ± 10 mmHg vs. 47 ± 11.3 mmHg) and right atrial pressure (16.5 ± 5.2 mmHg vs. 10.6 ± 5.2 mmHg). They received extracorporeal life support more frequently [33% vs 7% (p=0.02)], had worse Apache II score, 21.7 ± 7.4 vs 15.3 ± 5.3 (p=0.02), and a trend toward worse ventilator-free days 2.5 (IQR 6.5 – 32.5) vs. 17 (IQR 3 – 23) (p=0.08). There was no effect on development of primary graft dysfunction or ICU / hospital survival. One-year survival was worse (HR 4.45, 95% CI 1.3-22, p=0.02). Diastolic dysfunction was the only variable that correlated with overall survival (HR 5.4, 95% CI 1.3-22, P=0.02). Diastolic dysfunction leads to early post-operative morbidity and worse survival in PAH patients after double lung transplant. This article is protected by copyright. All rights reserved.
  • Costimulation blockade; America first, Canada second what about Norway?
    We read with interest the letter by Gill et al “commenting on costimulation blockade in large markets only» (1). They pinpoint the fact that the United States for long times have been the testing ground for development and commercialization of new therapeutics. This is a problem for therapeutics with small target patient populations such as immunosuppressant drugs. The authors anticipate that this will be a bigger issue in the future arguing that establishing a market foothold for new transplant therapeutics in the U.S. market likely will be even more difficult with the availability of generic immunosuppressant drugs. This article is protected by copyright. All rights reserved.
  • Increased Pre-Transplant Frequency of CD28+ CD4+ TEM Predicts Belatacept-Resistant Rejection in Human Renal Transplant Recipients
    While most human T cells express the CD28 costimulatory molecule constitutively, it is well-known that age, inflammation, and viral infection can drive the generation of CD28null T cells. In vitro studies have demonstrated that CD28null cell effector function is not impacted by the presence of the CD28 costimulation blocker belatacept. As such, a prevailing hypothesis suggests that CD28null cells may precipitate costimulation blockade-resistant rejection. However, CD28+ cells possess more proliferative and multi-functional capacity, factors that may increase their ability to successfully mediate rejection. Here, we performed a retrospective immunophenotypic analysis of adult renal transplant recipients who experienced acute rejection on belatacept treatment as compared to those that did not. Intriguingly, our findings suggest that patients possessing higher frequency of CD28+ CD4+ TEM prior to transplant were more likely to experience acute rejection following treatment with a belatacept-based immunosuppressive regimen. Mechanistically, CD28+ CD4+ TEM contained significantly more IL-2 producers. In contrast, CD28null CD4+ TEM isolated from stable belatacept-treated patients exhibited higher expression of the 2B4 coinhibitory molecule as compared to those isolated from patients who rejected. These data raise the possibility that pre-transplant frequencies of CD28+ CD4+ TEM could be used as a biomarker to predict risk of rejection following treatment with belatacept. This article is protected by copyright. All rights reserved.
  • Belatacept Resistant Rejection is Associated with CD28+ Memory CD8 T cells
    Recently newer therapies have been designed to more specifically target rejection in an effort to improve efficacy and limit unwanted toxicity. Belatacept, a CD28-CD80/86 specific reagent is associated with superior patient survival and graft function than traditional therapy but its adoption as a mainstay immunosuppressive therapy has been tempered by increased rejection rates. It is essential that the underlying mechanisms associated with this rejection be elucidated before belatacept is more widely employed. To that end we designed a study in a non-human primate kidney transplant model where animals were treated with either a belatacept- or a tacrolimus-based immunosuppressive regimen. Interestingly we found that elevated pre-transplant frequencies of CD28+CD8+TEMRA cells are associated with rejection on belatacept but not tacrolimus treatment. Further analysis showed that the CD28+CD8+TEMRA cells rapidly lose CD28 expression after transplant in those animals that go on to reject with the allograft infiltrate being predominantly CD28-. These data suggest that CD28+ memory T cells may be resistant to belatacept, capable of further differentiation including loss of CD28 expression while maintaining effector function. The unique signaling requirements of CD28+ memory T cells provide opportunities for the development of targeted therapies, which may synergize with belatacept to prevent costimulation independent rejection. This article is protected by copyright. All rights reserved.
  • An Interventional Study Using Cell Mediated Immunity to Personalize therapy for Cytomegalovirus infection after Transplantation
    Cell mediated immune responses predict clinical CMV events but have not been adopted into routine practice due to lack of interventional studies. Our objective was to demonstrate the safety and feasibility of early discontinuation of antivirals based on the real-time measurement of CMV-specific CMI in patients with CMV viremia. Transplant patients were enrolled at the onset of CMV viremia requiring antiviral therapy. CD8 T-cell responses were determined using the Quantiferon-CMV assay, and results were used to guide subsequent management. A total of 27 patients (median viral load at onset 10,900 IU/ml) were treated until viral load negative. At end of treatment 14/27 (51.9%) had a positive CMV-CMI response and had antivirals discontinued. The remaining 13/27 (48.1%) patients had a negative CMV-CMI response and received two months of secondary antiviral prophylaxis. In those with a positive CMI and early discontinuation of antivirals, only a single patient experienced a low-level asymptomatic recurrence. In contrast, recurrence was observed in 69.2% of CMI negative patients despite more prolonged antivirals (p=0.001). In conclusion, this is the first study to demonstrate the feasibility and safety of real-time CMV-specific CMI assessment to guide changes to the management of CMV infection. This article is protected by copyright. All rights reserved.
  • Ultrasound Imaging based on Molecular Targeting for Quantitative Evaluation of Hepatic Ischemia Reperfusion Injury
    The present study aimed to quantitatively diagnose and monitor the therapy response of hepatic ischemia reperfusion injury (IRI) with targeted ultrasound (US) imaging. Targeted microbubbles (MBs) were fabricated, and the binding of ICAM-1 antibodies to MBs was observed. To establish a quantitative method based on targeted US imaging, contrast-enhanced ultrasound (CEUS) was applied on IRI rats. After andrographolide treatment, the IRI rats were subjected to the quantitative targeted US imaging for a therapeutic effect. Effective binding of ICAM-1 antibodies to MBs was observed. According to the quantitative targeted US imaging, the ICAM-1 normalized intensity difference (NID) in IRI rats (38.74 ± 15.08%) was significantly higher than that in the control rats (10.08 ± 2.52%, P = 0.048). Furthermore, different degrees of IRI (mild IRI, moderate to severe IRI) were distinguished by the use of NID (37.14 ± 2.14, 22.34 ± 1.08, P = 0.002). Analysis of mRNA expression demonstrated the accuracy of analyzing the NID using quantitative targeted US imaging (R2 = 0.7434, P < 0.001). Andrographolide treatment resulted in obviously weakened NID of ICAM-1 (17.7 ± 4.8% vs 34.2 ± 6.6%, P < 0.001). The study showed the potential of the quantitative targeted US imaging method for the diagnosis and therapeutic monitoring of IRI. This article is protected by copyright. All rights reserved.
  • Successful Treatment of KSHV Inflammatory Cytokine Syndrome (KICS) after Kidney-Liver Transplant: Correlations with HHV8 miRNome and Specific T-Cell Response
    In post-transplant patients, HHV-8/KSHV infection is known to cause aggressive tumors, as well as severe non-neoplastic complications. These latter syndromes are driven by HHV-8/KSHV lytic reactivations and related hyper-inflammatory host responses, typically characterized by high viral loads, elevated levels of cytokines and other inflammation biomarkers, cytopenia, organ failure, high fever, and worsening conditions (with no evidence of B-cell neoplasias). These disorders are associated with a high mortality rate, often due to lack of prompt diagnosis, effective therapeutic approaches, and adequate follow up. Indeed, these features resemble most of those defining the so-called KSHV inflammatory cytokine syndrome (KICS), which was recently recognized in HIV-positive patients. Here we describe, for the first time, a case of KICS-like non-neoplastic recurrent complication occurring in an HIV-negative post-transplant patient, which was successfully treated by combination of anti-CD20 monoclonal therapy, antivirals, and modification of immunosuppressive regimen. In addition to clinical and laboratory findings collected during 3-year-long follow up, we also report novel experimental data on HHV-8-specific T-cell dynamics and circulating miRNA profile, showing correlations with clinical course and other laboratory markers (including viral load, CRP and cytokine levels), thus providing useful information about abnormal cellular and cytokine dynamics underlying of HHV-8-associated inflammatory disorders in post-transplant patients. This article is protected by copyright. All rights reserved.
  • Pancreas-after-Islet (PAI) transplantation in non-uremic Type 1 diabetes: A strategy for restoring durable insulin independence
    Islet transplantation offers a minimally-invasive approach for beta cell replacement in diabetic patients with hypoglycemic unawareness. Attempts at insulin independence may require multiple islet re-infusions from distinct donors, thus increasing the risk for allogeneic sensitization. Currently, solid organ pancreas transplant is the only remaining surgical option following failed islet transplantation in the US. However, the immunologic impact of repeated exposure to donor antigens on subsequent pancreas transplantation is unclear. Here we describe a case series of seven patients undergoing solid organ pancreas transplant following islet graft failure, with long-term follow-up of pancreatic graft survival and renal function. Despite highly variable panel-reactive antibody (PRA) levels prior to pancreas transplant (mean 27±35%), all seven patients achieved stable and durable insulin independence with a mean follow-up of 6.7 years. Mean hemoglobin A1c (HgbA1c) values improved significantly from post-islet, pre-pancreas levels (mean 8.1±1.5%) to post-pancreas levels (mean 5.3±0.1%; p=0.0022). Three patients experienced acute rejection episodes successfully managed with thymoglobulin and methylprednisolone, and none of these pre-uremic type 1 diabetic recipients developed Stage 4 or 5 chronic kidney disease postoperatively. These results support pancreas-after-islet (PAI) transplantation with aggressive immunosuppression and protocol biopsies as a viable strategy to restore insulin independence after islet graft failure. This article is protected by copyright. All rights reserved.
  • Regulatory T cells Promote Natural Killer Cell Education in Mixed Chimeras
    Therapeutic administration of regulatory T cells (Tregs) leads to engraftment of conventional doses of allogeneic bone marrow (BM) in non-irradiated recipient mice conditioned with costimulation blockade and mTOR inhibition. The mode of action responsible for this Treg effect is poorly understood but may encompass the control of costimulation blockade-resistant natural killer (NK) cells. We show that transient NK cell depletion at the time of BM transplantation (BMT) led to BM engraftment and persistent chimerism without Treg transfer, but failed to induce skin graft tolerance. In contrast, the permanent absence of anti-donor NK reactivity in mice grafted with F1 BM was associated with both chimerism and tolerance comparable to Treg therapy, implying that NK cell tolerization is a critical mechanism of Treg therapy. Indeed, NK cells of Treg-treated BM recipients reshaped their receptor repertoire in the presence of donor MHC in a manner suggesting attenuated donor-reactivity. These results indicate that adoptively transferred Tregs prevent BM rejection, at least in part, by suppressing NK cells and promote tolerance by regulating the appearance of NK cells expressing activating receptors to donor class I MHC. This article is protected by copyright. All rights reserved.
  • Broken Chains and Reneging: A Review of 1,748 Kidney Paired Donation Transplants
    Concerns regarding the potential for broken chains and reneges within kidney paired donation (KPD) and its effect on chain length have been previously raised. While these concerns have been tested in simulation studies, “real world” data has yet to be evaluated. The purpose of this study was to evaluate the actual rate and cause of broken chains within a large KPD program. All patients undergoing renal transplantation through the National Kidney Registry from 2008 through May 2016 were included for analysis. Broken chains and loops were identified. A total of 344 chains and 78 loops were completed during the study period yielding a total of 1,748 transplants. Twenty broken chains and one broken loop were identified. The mean chain length (# of transplants) within broken chains was 4.8 compared to 4.6 of completed chains (p=0.78). The most common causes of a broken chain were donor medical issues incurred while acting as a bridge donor (n=8), donors electing not to proceed (n=6), and kidneys being declined by the recipient surgeon (n=4). All recipients involved in a broken chain have subsequently received a transplant. Based on the results broken chains are infrequent, rarely due to lack of donor motivation, and have no significant impact on chain length. This article is protected by copyright. All rights reserved.
  • Prolonged Survival Following Pig-to-Primate Liver Xenotransplantation Utilizing Exogenous Coagulation Factors and Co-Stimulation Blockade
    Since the first attempt in 1968, survival following pig-to-primate liver xenotransplantation (LXT) has been limited. We evaluated a model utilizing α-1,3-galactosyltransferase knockout donors, continuous post-transplant infusion of human prothrombin concentrate complex and immunosuppression including anti-thymocyte globulin, FK-506, methylprednisone and co-stimulation blockade (belatacept, n=3 or anti-CD40mAb, n=1) to extend survival. Baboon #1 remained well until POD25 when euthanasia was required due to cholestasis and plantar ulcers. Baboon #2 was euthanized following a seizure on POD5, despite normal LFTs and no apparent pathology. Baboon # 3 demonstrated initial stable liver function, but was euthanized on POD8 due to worsening LFTs. Pathology revealed C4d positivity, extensive hemorrhagic necrosis and a focal CMV inclusion. Baboon # 4 was clinically well with stable LFTs until POD29, when euthanasia was again necessitated by plantar ulcerations as well as rising LFTs. Final pathology was C4d negative and without evidence of rejection, inflammation or TMA. Thus, nearly one-month rejection-free survival has been achieved following LXT in 2 of 4 continuous recipients, demonstrating that the porcine liver can support life in primates for several weeks and is encouraging for potential clinical application of LXT as a bridge to allotransplantation for patients with acute-on-chronic or fulminant hepatic failure. This article is protected by copyright. All rights reserved.
  • Comprehensive Review on Colorectal Cancer and Transplant
    Colon cancer (CRC) is a common malignancy worldwide. Some studies suggest that organ recipients are at a higher risk for CRC than the general population. The underlying transplant indications and their inherent risk factors for CRC may drive the variation in incidence rates that are seen in patients receiving different allografts. Recipients with cystic fibrosis are now recognized as a population at high risk for CRC at a young age. Transplant recipients have high mortality following a CRC diagnosis, even if it is detected at an early stage. Certain types of immunosuppression have been shown to accelerate cancer transformation and may contribute to the more aggressive phenotype seen in organ recipients. Given the high incidence and progressive nature of post-transplant CRC, shorter screening intervals with a modality that can detect early stage polyps may be essential to prevent mortality. Future research is needed to better elucidate the role of immunosuppression in carcinogenesis. This comprehensive review examines CRC risk, screening, and management specific to organ transplant candidates and recipients. This article is protected by copyright. All rights reserved.
  • A multicenter study on long-term outcomes after lung transplantation comparing donation after circulatory death and donation after brain death
    The implementation of donation after circulatory death category 3 (DCD3) was one of the attempts to reduce the gap between supply and demand of donor lungs. In the Netherlands, the total number of potential lung donors was greatly increased by the availability of DCD3 lungs in addition to the initial standard usage of donation after brain death (DBD) lungs. From the three lung transplant centers in the Netherlands, 130 DCD3 recipients were one-to-one nearest neighbor propensity score matched with 130 DBD recipients. The primary end points were primary graft dysfunction (PGD), post-transplant lung function, freedom from chronic lung allograft dysfunction (CLAD) and overall survival. PGD did not differ between the groups. Post-transplant lung function was comparable after bilateral lung transplantation, but seemed worse after DCD3 single lung transplantation. The incidence of CLAD (p=0.17) nor the freedom from CLAD (p=0.36) nor the overall survival (p=0.40) was significantly different between both groups. The presented multicenter results are derived from a national context where one third of the lung transplantations is performed with DCD3 lungs. We conclude that the long-term outcome after lung transplantation with DCD3 donors is similar to DBD donors and that DCD3 donation can substantially enlarge the donor pool. This article is protected by copyright. All rights reserved.
  • In vitro induction of human regulatory T-cells (iTregs) using conditions of low tryptophan plus kynurenines
    Thymic regulatory T cells (tTreg) or induced Tregs (iTregs) suppress murine acute graft-versus-host disease (GVHD). Previously we demonstrated that plasmacytoid dendritic cell (pDC) indoleamine 2,3-dioxygenase (IDO) fosters the in vitro development of human iTregs via tryptophan depletion and kynurenine (Kyn) metabolites. We now show that stimulation of naïve CD4+ T cells in low tryptophan (Low Trp) plus Kyn supports human iTreg generation. In vitro, low Trp+Kyn iTreg and tTregs potently suppress Teffector cell proliferation equivalently but are phenotypically distinct. As compared to tTreg or Teffector, bioenergetics profiling reveals that Low Trp+Kyn iTreg have increased basal glycolysis and oxidative phosphorylation and also use glutaminolysis as an energy source. Low Trp+Kyn iTreg viability was reliant on IL-2 in vitro. Although in vivo IL-2 administration increased Low Trp+Kyn iTreg persistence upon adoptive transfer into immune deficient mice given peripheral blood mononuclear cells to induce GVHD, IL-2 supported iTregs did not improve recipient survival. We conclude that Low Trp+Kyn create suppressive iTregs that have high metabolic needs that will need to be addressed prior to clinical translation. This article is protected by copyright. All rights reserved.
  • Neuroinvasive St. Louis Encephalitis Virus Infection in Solid Organ Transplant Recipients
    In the summer of 2015, 3 unrelated solid organ transplant recipients had meningoencephalitis suggestive of West Nile virus (WNV) infection in Phoenix, Arizona. Testing was inconclusive but was later confirmed as St. Louis encephalitis (SLE). We retrospectively reviewed clinical manifestations, treatment, and outcomes of these transplant recipients. Common symptoms were fever, rigors, diarrhea, headache, and confusion. One patient died 3 days after hospitalization. Therapy for the 2 patients was initiated with interferon alfa-2b (IFN) and intravenous immunoglobulin G (IVIG) (IFN+IVIG in combination). Both patients tested positive for WNV by serologic assay, but SLE virus (SLEV) infection was later confirmed by plaque reduction neutralization test at a reference laboratory. Clinical improvement was observed within 72 hours after IFN+IVIG initiation. SLEV has been an uncommon cause of neuroinvasive disease in the United States. Accurate, timely diagnosis is hindered because of similar clinical presentation of neuroinvasive WNV and SLE, serologic cross-reactivity, and lack of a commercially available serologic assay for SLEV. There is currently no approved therapy for flaviviral neuroinvasive disease. Anecdotal reports indicate varying success with IFN, IVIG, or IFN+IVIG in WNV neuroinvasive disease. The same regimen might be of value for immunocompromised persons with neuroinvasive SLEV infection. This article is protected by copyright. All rights reserved.
  • Cutaneous Toxicities from Transplant-related Medications
    Despite the abundance of information on cutaneous malignancies associated with solid organ transplantation in the transplant literature, there is limited information regarding non-malignant skin changes after transplantation. There are numerous skin toxicities secondary to immunosuppressive and other transplant-related medications that can vary in presentation, severity, and prognosis. In order to limit associated morbidity and mortality, SOTR care providers should effectively identify and manage cutaneous manifestations secondary to drug toxicity. Toxicities from the following transplant related medications will be discussed: Antithymocyte globulins; Systemic steroids; Cyclosporine; Tacrolimus; Azathioprine; Mycophenolate mofetil; mTOR inhibitors: Sirolimus and Everolimus; Basiliximab and Daclizumab; Belatacept; Voriconazole. This article is protected by copyright. All rights reserved.
  • Lepromatous leprosy in a renal transplant recipient
    Leprosy is a chronic granulomatous disease caused by acid fast bacillus Mycobacterium Leprae. It is rare in organ transplant patients; cases have been reported in three heart, one liver, and 12 renal transplantation patients in Worldwide (1,2). We report on a patient with lepromatous leprosy presenting six years after renal transplantation. A 38-year-old male was admitted with multiple erythematous lesions appeared over the patient's face, extremities, and trunk. This article is protected by copyright. All rights reserved.
  • Real time central assessment of kidney transplant indication biopsies by microarrays: The INTERCOMEX Study
    We performed a prospective trial to assess the feasibility of real-time central molecular assessment of kidney transplant biopsies from 10 North American and European centers. Biopsies taken one day to 34 years post-transplant were stabilized in RNAlater, couriered overnight at ambient temperature to the central laboratory, and processed (29 hour workflow) using microarrays to assess T cell-mediated and antibody-mediated rejection (TCMR, ABMR). Of 538 biopsies submitted, 519 (96%) were sufficient for microarray analysis (average length 3mm). Automated reports were generated without knowledge of histology and HLA antibody, assigning diagnoses based on Molecular Microscope Diagnostic System (MMDx) classifier algorithms derived by machine learning and signed out by one observer. Agreement between MMDx and histology (balanced accuracy) was TCMR 77%, ABMR 77%, and no rejection 76%. A classification tree derived to provide automated sign-outs predicted the observer sign-outs with >90% accuracy. In 451 biopsies where feedback was obtained, clinicians indicated that MMDx more frequently agreed with clinical judgement (87%) than did histology (80%) (p=0.0042). In 81% of feedback forms, clinicians reported that MMDx would increase confidence in management compared to conventional assessment alone. We conclude that real-time central molecular assessment is feasible and offers a useful new dimension in biopsy interpretation. Clinicaltrials. govNCT#01299168. This article is protected by copyright. All rights reserved.
  • Complement dependence of murine costimulatory blockade-resistant cellular cardiac allograft rejection
    Building upon studies showing that ischemia/reperfusion-(IR)-injury is complement-dependent, we tested links among complement activation, transplant associated ischemia-reperfusion injury, and murine cardiac allograft rejection. We transplanted BALB/c hearts subjected to 8h cold ischemic storage (CIS) into CTLA4Ig-treated WT or c3-/- B6 recipients. Whereas allografts subjected to 8h CIS rejected in WT recipients with a median survival time (MST) of 37d, identically treated hearts survived >60d in c3-/- mice (p<0.05, n=4-6/group). Mechanistic studies showed recipient C3 deficiency prevented induction of intragraft and serum chemokines/cytokines, and blunted the priming, expansion and graft infiltration of interferon-gamma-(IFNγ)-producing, donor-reactive T cells. MST of hearts subjected to 8h CIS was >60d in mannose binding lectin-(mb1-/-/mbl2-/- recipients, and 42d in factor-B-(cfb)-/- recipients (n=4-6/group, p<0.05, mb1-/-/mbl2-/- vs cfb-/-), implicating the MBL (not alternative) pathway. To pharmacologically target MBL-initiated complement activation, we transplanted BALB/c hearts subjected to 8h CIS into CTLA4Ig-treated WT B6 recipients±C1-inhibitor (C1-INH). Remarkably, peri-transplant administration of C1-INH prolonged graft survival (MST >60d, p<0.05 vs. controls, n=6) and prevented CI-induced increases in donor-reactive IFNγ-producing spleen cells (p<0.05). These new findings link donor IR-injury to T cell-mediated rejection through MBL-initiated, complement activation and support testing C1-INH administration to prevent CTLA4Ig-resistant rejection of deceased donor allografts in human transplant patients. This article is protected by copyright. All rights reserved.
  • Deciphering tacrolimus-induced toxicity in pancreatic β-cells
    β-cell transcription factors like: FoxO1, MafA, PDX-1, NeuroD, are dysfunctional in type 2 diabetes (T2DM). PTDM resembles T2DM and reflects interaction between pre-transplant insulin resistance and immunosuppressants, mainly calcineurin inhibitors. We evaluated the effect of tacrolimus, cyclosporine-A and metabolic stressors (glucose+palmitate) on insulinoma β-cells (INS-1) in vitro and in pancreata of obese and lean Zucker rats. Cells were cultured for five days with 100μM palmitate and 22mM glucose; cyclosporin-A (250ng/mL) or tacrolimus (15ng/mL) were added the last 48h. Glucose+palmitate increased nuclear FoxO1 and decreased nuclear MafA. Tacrolimus on top of glucose+palmitate magnified these changes in nuclear factors whereas cyclosporin-A did not. On top of glucose+palmitate, both drugs reduced insulin content and tacrolimus also affected insulin secretion. Tacrolimus withdrawal or conversion to cyclosporin-A restored these changes. Similar results were observed in pancreata of obese animals on calcineurin inhibitors. Tacrolimus and cyclosporin-A, on top of glucose+palmitate induced a comparable inhibition of calcineurin-NFAT. Thus, tacrolimus potentiates glucolipotoxicity in β-cells, possibly by sharing common pathways of β-cell dysfunction. Tacrolimus-induced β-cell dysfunction is potentially reversible. The inhibition of calcineurin-NFAT pathway may contribute to the diabetogenic effect of calcineurin inhibitors but does not explain the stronger of tacrolimus compared with cyclosporine-A. This article is protected by copyright. All rights reserved.
  • Prevention of the Osmotic Demyelination Syndrome after Liver Transplantation: A Multidisciplinary Perspective
    The osmotic demyelination syndrome (ODS) is a serious neurologic condition that occurs in the setting of rapid correction of hyponatremia. It presents with protean manifestations, from encephalopathy to the “locked-in” syndrome. ODS can complicate liver transplantation (LT), and its incidence may increase with the inclusion of serum sodium as a factor in the Model for End-Stage Liver Disease score. A comprehensive understanding of risk factors for the development of ODS in the setting of LT, along with recommendations to mitigate the risk of ODS, are necessary. The literature to date on ODS in the setting of LT was reviewed. Major risk factors for the development of ODS include severe pre-transplant hyponatremia (Serum sodium [SNa] < 125 mEq/L), the magnitude of change in SNa pre- vs. post-transplant, higher positive intraoperative fluid balance, and the presence of postoperative hemorrhagic complications. Strategies to reduce the risk of ODS include correcting hyponatremia pre-transplant via fluid restriction and/or ensuring an appropriate rate of increase from the preoperative SNa via close attention to fluid and electrolyte management both during and after surgery. Multidisciplinary management involving transplant hepatology, nephrology, neurology, surgery, and anesthesiology/critical care is key to performing LT safely in patients with hyponatremia. This article is protected by copyright. All rights reserved.
  • Histological evolution of BK virus associated nephropathy: Importance of integrating clinical and pathological findings
    Long term clinicopathological studies of BK-associated nephropathy (PyVAN) are not available. We studied 206 biopsies (71 patients), followed 3.09±1.46y after immunosuppression reduction. The biopsy features (% SV40+staining and inflammation +/- acute rejection) were correlated with viral load dynamics and serum creatinine to define the clinicopathological status (PyVCPS). Incidence of acute rejection was 28% in the 2ndbiopsy and 50% subsequently (25% mixed TCMR+AMR; rejection overall affected 38% of patients (>50% AMR). Graft loss was 15.4% (0.8-5.3y after PyVAN); 76% had complete viral clearance (mean 28weeks). The only predictors of graft loss were acute rejection (TCMR p=0.008, any type p=0.07), and increased “t” and “ci” in the 2ndbiopsy (p=0.006 and 0.048). Higher peak viremia correlated with poorer viral clearance (p=.002). Presumptive and proven PyVAN had similar presentation, evolution and outcome. Late PyVAN (>2 years,9.8%) justifies BK viremia evaluation at any point with graft dysfunction and/or biopsy evaluation. This study describes the histological evolution of PyVAN and corresponding clinicopathological correlations. Although the pathological features overall reflect the viral and immunological interactions, the PyVAN course remains difficult to predict based on any single feature. Appropriate clinical management requires repeat biopsies and determination of the PyVCPS at relevant time points, for corresponding personalized immunosuppression adjustment. This article is protected by copyright. All rights reserved.
  • Risk of thyroid cancer among solid organ transplant recipients
    Solid organ transplant recipients have an elevated incidence of thyroid cancer. We evaluated a wide range of potential risk factors in a cohort of 229,300 U.S. solid organ transplant recipients linked with 15 stage/regional cancer registries (1987-2012). Incidence rate ratios (IRRs) were adjusted for age, sex, race/ethnicity, transplanted organ, year of transplant, and time since transplant. Hazards ratios (HRs) for death and/or graft failure were adjusted for age, sex, race/ethnicity, transplanted organ, and year of transplant. Following transplant, 356 thyroid cancers were diagnosed. Thyroid cancer incidence was 2.50-fold higher in transplant recipients than the general population (95%CI 2.25-2.77). Among recipients of different organs, kidney recipients had the highest incidence of thyroid cancer (IRR=1.26, 95%CI 1.03-1.53). Elevated thyroid cancer incidence was associated with cholestatic liver disease/cirrhosis as an indication for liver transplant (IRR=1.69, 95%CI 1.09-2.63), hypertensive nephrosclerosis as an indication for kidney transplant (IRR=1.41, 95%CI 1.03-1.94), and longer prior dialysis among kidney recipients (5+ versus <1 year, IRR=1.92, 95%CI 1.32-2.80;P-trend<0.01). Post-transplant diagnosis of thyroid cancer was associated with modestly increased risk of death (HR=1.33, 95%CI 1.02-1.73). Overall, our results suggest that end-stage organ disease and longer duration of dialysis may contribute to higher thyroid cancer incidence in transplant recipients. This article is protected by copyright. All rights reserved.
  • Chronic Antibody-Mediated Rejection in Nonhuman Primate Renal Allografts: Validation of Human Histological and Molecular Phenotypes
    Molecular testing represents a promising adjunct for the diagnosis of antibody-mediated rejection (AMR). Here, we apply a novel gene expression platform in sequential formalin-fixed paraffin-embedded samples from nonhuman primate (NHP) renal transplants. We analyzed 34 previously described gene transcripts related to AMR in humans in 197 archival NHP samples, including 102 from recipients that developed chronic AMR, 80 from recipients without AMR, and 15 normal native nephrectomies. Three endothelial genes (VWF, DARC, and CAV1), derived from 10-fold cross-validation receiver operating characteristic curve analysis, demonstrated excellent discrimination between AMR and non-AMR samples (area under the curve = 0.92). This three-gene set correlated with classic features of AMR, including glomerulitis, capillaritis, glomerulopathy, C4d deposition, and DSAs (r = 0.39–0.63, p < 0.001). Principal component analysis confirmed the association between three-gene set expression and AMR and highlighted the ambiguity of v lesions and ptc lesions between AMR and T cell–mediated rejection (TCMR). Elevated three-gene set expression corresponded with the development of immunopathological evidence of rejection and often preceded it. Many recipients demonstrated mixed AMR and TCMR, suggesting that this represents the natural pattern of rejection. These data provide NHP animal model validation of recent updates to the Banff classification including the assessment of molecular markers for diagnosing AMR.
  • Zika Virus RNA in an Asymptomatic Donor's Vitreous: Risk of Transmission?
  • Living Donor Uterus Transplantation: A Single Center's Observations and Lessons Learned From Early Setbacks to Technical Success
    Uterus transplantation is a vascularized composite allograft transplantation. It allows women who do not have a uterus to become pregnant and deliver a baby. In this paper, we analyze the first five cases of living donor uterus transplantation performed in the United States. The first three recipients lost their uterus grafts at days 14, 12, and 6, respectively, after transplant. Vascular complications, related to both inflow and outflow problems, were identified as the primary reason for the graft losses. Two recipients, at 6 and 3 mo, respectively, after transplant, have functioning grafts with regular menstrual cycles. Ultimate success will be claimed only after a live birth. This paper is an in-depth analysis of evaluation, surgical technique, and follow-up of these five living donor uterus transplants. The lessons learned were instrumental in allowing us to evolve from failure to technical and functional success. We aim to share our conclusions and build on knowledge in the evolving field of uterus transplantation.
  • Kidney Paired-Donation Program Versus Global Kidney Exchange in India
  • Effect of Empagliflozin on Tacrolimus-Induced Pancreas Islet Dysfunction and Renal Injury
    An inhibitor of sodium glucose co-transporter type 2 (SGLT-2) is recommended in type 2 diabetes mellitus (DM) but its use is still undetermined in tacrolimus (TAC)-induced DM. We evaluated the effect of empagliflozin (Em) on TAC-induced pancreatic islet dysfunction and renal injury in an experimental model of TAC-induced DM and in vitro. TAC induced a twofold increase in SGLT-2 expression, while Em decreased SGLT-2 expression and further increased urinary glucose excretion compared to the TAC group. Em reduced hyperglycemia and increased plasma insulin level, pancreatic islet size, and glucose-stimulated insulin secretion compared to the TAC group. In kidney, Em alleviated TAC-induced renal dysfunction and decreased albumin excretion and histological injury compared with the TAC group. Increased oxidative stress and apoptotic cell death by TAC was remarkably decreased with Em in serum and pancreatic and renal tissues. In in vitro study, TAC decreased cell viability and increased reactive oxygen species (ROS) production in both insulin-secreting beta-cell derived (INS-1) and human kidney-2 (HK-2) cell lines. Addition of Em increased cell viability and decreased ROS production in HK-2 but not in INS-1 cell lines. This suggests that Em is effective in controlling TAC-induced hyperglycemia and has direct protective effect on TAC-induced renal injury.
  • A Transplant-Specific Quality Initiative–Introducing TransQIP: A Joint Effort of the ASTS and ACS
    In an attempt to improve surgical quality in the field of transplantation, the American College of Surgeons (ACS) and American Society of Transplant Surgeons have initiated a national quality improvement program in transplantation. This transplant-specific quality improvement program, called TransQIP, has been built from the ground up by transplant surgeons and captures detailed information on donor and recipient factors as well as transplant-specific outcomes. It is built upon the existing ACS/National Surgical Quality Improvement Program infrastructure and is designed to capture 100% of liver and kidney transplants performed at participating sites. TransQIP has completed its alpha pilot and will embark upon its beta phase at approximately 30 centers in the spring of 2017. Going forward, we anticipate TransQIP will help satisfy Centers for Medicare and Medicaid Services requirements for a quality improvement program, surgeon requirements for maintenance of certification, and qualify as a clinical practice improvement activity under the Merit-Based Incentive Payment System. Most importantly, we believe TransQIP will provide insight into surgical outcomes in transplantation that will allow the field to provide better care to our patients.
  • Allo-HLA Cross-Reactivities of Cytomegalovirus-, Influenza-, and Varicella Zoster Virus–Specific Memory T Cells Are Shared by Different Healthy Individuals
    Virus-specific T cells can recognize allogeneic HLA (allo-HLA) through TCR cross-reactivity. The allospecificity often differs by individual (private cross-reactivity) but also can be shared by multiple individuals (public cross-reactivity); however, only a few examples of the latter have been described. Because these could facilitate alloreactivity prediction in transplantation, we aimed to identify novel public cross-reactivities of human virus-specific CD8+ T cells directed against allo-HLA by assessing their reactivity in mixed-lymphocyte reactions. Further characterization was done by studying TCR usage with primer-based DNA sequencing, cytokine production with ELISAs, and cytotoxicity with 51chromium-release assays. We identified three novel public allo-HLA cross-reactivities of human virus-specific CD8+ T cells. CMV B35/IPS CD8+ T cells cross-reacted with HLA-B51 and/or HLA-B58/B57 (23% of tetramer-positive individuals), FLU A2/GIL (influenza IMP[58-66] HLA-A*02:01/GILGFVFTL) CD8+ T cells with HLA-B38 (90% of tetramer-positive individuals), and VZV A2/ALW (varicella zoster virus IE62[593-601] HLA-A*02:01/ALWALPHAA) CD8+ T cells with HLA-B55 (two unrelated individuals). Cross-reactivity was tested against different cell types including endothelial and epithelial cells. All cross-reactive T cells expressed a memory phenotype, emphasizing the importance for transplantation. We conclude that public allo-HLA cross-reactivity of virus-specific memory T cells is not uncommon and may create novel opportunities for alloreactivity prediction and risk estimation in transplantation.
  • Rat Hindlimb Cryopreservation and Transplantation: A Step Toward “Organ Banking”
    In 2016, over 5 million reconstructive procedures were performed in the United States. The recent successes of clinical vascularized composite allotransplantations, hand and face transplantations included, established the tremendous potential of these life-enhancing reconstructions. Nevertheless, due to limited availability and lifelong immunosuppression, application is limited. Long-term banking of composite transplants may increase the availability of esthetically compatible parts with partial or complete HLA matching, reducing the risk of rejection and the immunosuppressive burden. The study purpose was to develop efficient protocols for the cryopreservation and transplantation of a complete rodent limb. Directional freezing is a method in which a sample is cooled at a constant-velocity linear temperature gradient, enabling precise control of the process and ice crystal formation. Vitrification is an alternative cryopreservation method in which the sample solidifies without the formation of ice crystals. Testing both methods on a rat hindlimb composite tissue transplantation model, we found reliable, reproducible, and stable ways to preserve composite tissue. We believe that with further research and development, cryopreservation may lead to composite tissue “banks.” This may lead to a paradigm shift from few and far apart emergent surgeries to wide-scale, well-planned, and better-controlled elective surgeries.
  • A Very Different Paradigm for Living Kidney Donor Risk
  • Posttransplant Lymphoproliferative Disorder After Clinical Islet Transplantation: Report of the First Two Cases
    We report the first two cases of posttransplant lymphoproliferative disorder (PTLD) in recipients of islet transplants worldwide. First, a 44-year-old recipient of three islet infusions developed PTLD 80 months after his initial transplantation, presenting with abdominal pain and diffuse terminal ileum thickening on imaging. He was treated with surgical excision, reduction of immunosuppression, and rituximab. Seven months later, he developed central nervous system PTLD, presenting with vertigo and diplopia; immunosuppression was discontinued, resulting in graft loss, and he was given high-dose methotrexate and underwent consolidative autologous stem cell transplantation. He remains in remission 37 months after the initial diagnosis. Second, a 58-year-old female recipient of two islet infusions developed PTLD 24 months after initial islet infusion, presenting with pancytopenia secondary to extensive bone marrow involvement. Immunosuppression was discontinued, resulting in graft loss, and she received rituximab and chemotherapy, achieving complete remission. Both patients were monomorphic B cell PTLD subtype by histology and negative for Epstein–Barr virus in tissue or blood. These cases document the first occurrences of this rare complication in islet transplantation, likely secondary to prolonged, intensive immunosuppression, and highlight the varying clinical manifestations of PTLD. Further studies are needed to determine incidence rate and risk factors in islet transplantation.
  • Considering Tangible Benefit for Interdependent Donors: Extending a Risk–Benefit Framework in Donor Selection
    From its infancy, live donor transplantation has operated within a framework of acceptable risk to donors. Such a framework presumes that risks of living donation are experienced by the donor while all benefits are realized by the recipient, creating an inequitable distribution that demands minimization of donor risk. We suggest that this risk-tolerance framework ignores tangible benefits to the donor. A previously proposed framework more fully considers potential benefits to the donor and argues that risks and benefits must be balanced. We expand on this approach, and posit that donors sharing a household with and/or caring for a potential transplant patient may realize tangible benefits that are absent in a more distantly related donation (e.g. cousin, nondirected). We term these donors, whose well-being is closely tied to their recipient, “interdependent donors.” A flexible risk–benefit model that combines risk assessment with benefits to interdependent donors will contribute to donor evaluation and selection that more accurately reflects what is at stake for donors. In so doing, a risk–benefit framework may allow some donors to accept greater risk in donation decisions.
  • Reply to Comment on the Article “OPTN/SRTR 2015 Annual Data Report: Pancreas”
  • Depletion-Resistant CD4 T Cells Enhance Thymopoiesis During Lymphopenia
    Lymphoablation is routinely used in transplantation, and its success is defined by the balance of pathogenic versus protective T cells within reconstituted repertoire. While homeostatic proliferation and thymopoiesis may both cause T cell recovery during lymphopenia, the relative contributions of these mechanisms remain unclear. The goal of this study was to investigate the role of the thymus during T cell reconstitution in adult allograft recipients subjected to lymphoablative induction therapy. Compared with euthymic mice, thymectomized heart allograft recipients demonstrated severely impaired CD4 and CD8 T cell recovery and prolonged heart allograft survival after lymphoablation with murine anti-thymocyte globulin (mATG). The injection with agonistic anti-CD40 mAb or thymus transplantation only partially restored T cell reconstitution in mATG-treated thymectomized mice. After mATG depletion, residual CD4 T cells migrated into the thymus and enhanced thymopoiesis. Conversely, depletion of CD4 T cells before lymphoablation inhibited thymopoiesis at the stage of CD4−CD8−CD44hiCD25+ immature thymocytes. This is the first demonstration that the thymus and peripheral CD4 T cells cooperate to ensure optimal T cell reconstitution after lymphoablation. Targeting thymopoiesis through manipulating functions of depletion-resistant helper T cells may thus improve therapeutic benefits and minimize the risks of lymphoablation in clinical settings.
  • Comment: Kidney Exchange to Overcome Financial Barriers to Kidney Transplantation
  • Vascularized Composite Allograft Donation and Transplantation: A Survey of Public Attitudes in the United States
    Vascularized composite allograft (VCA) transplantation has emerged as a groundbreaking surgical intervention to return identity and function following traumatic injury, congenital deformity, or disfigurement. While public attitudes toward traditional organ/tissue donation are favorable, little is known about attitudes toward VCA donation and transplantation. A survey was conducted of 1485 U.S. residents in August 2016 to assess VCA donation attitudes. Participants also completed the Revised Health Care System Distrust Scale. Most respondents were willing to donate hands/forearms (67.4%) and legs (66.8%), and almost half (48.0%) were willing to donate the face. Three-quarters (74.4%) of women were willing to donate the uterus; 54.4% of men were willing to donate the penis. VCA donation willingness was more likely among whites and Hispanics (p < 0.001), registered organ/tissue donors (p < 0.001), and those with less health care system distrust (p < 0.001) and media exposure to VCA transplantation (p = 0.003). Many who opposed VCA donation expressed concerns about psychological discomfort, mutilation, identity loss, and the reaction of others to seeing familiar body parts on a stranger. Attitudes toward VCA donation are favorable overall, despite limited exposure to VCA messaging and confusion about how VCA donation occurs. These findings may help guide the development and implementation of VCA public education campaigns.
  • Risk of End-Stage Renal Disease in HIV-Positive Potential Live Kidney Donors
    New federal regulations allow HIV-positive individuals to be live kidney donors; however, potential candidacy for donation is poorly understood given the increased risk of end-stage renal disease (ESRD) associated with HIV infection. To better understand this risk, we compared the incidence of ESRD among 41 968 HIV-positive participants of North America AIDS Cohort Collaboration on Research and Design followed for a median of 5 years with the incidence of ESRD among comparable HIV-negative participants of National Health and Nutrition Examination III followed for a median of 14 years. We used risk associations from multivariable Cox proportional hazards regression to derive cumulative incidence estimates for selected HIV-positive scenarios (no history of diabetes, hypertension, AIDS, or hepatitis C virus coinfection) and compared these estimates with those from similarly selected HIV-negative scenarios. For 40-year-old HIV-positive individuals with health characteristics that were similar to those of age-matched kidney donors, viral load <400 copies/mL, and CD4+ count ≥500 cells/μL, the 9-year cumulative incidence of ESRD was higher than that of their HIV-negative peers, yet still low: 2.5 versus 1.1 per 10 000 among white women, 3.0 versus 1.3 per 10 000 among white men, 13.2 versus 3.6 per 10 000 among black women, and 15.8 versus 4.4 per 10 000 among black men. HIV-positive individuals with no comorbidities and well-controlled disease may be considered low-risk kidney donor candidates.
  • HLA Mismatching Favoring Host-Versus-Graft NK Cell Activity Via KIR3DL1 Is Associated With Improved Outcomes Following Lung Transplantation
    Chronic lung allograft dysfunction (CLAD) is linked to rejection and limits survival following lung transplantation. HLA-Bw4 recipients of HLA-Bw6 grafts have enhanced host-versus-graft (HVG) natural killer (NK) cell activity mediated by killer cell immunoglobulin-like receptor (KIR)3DL1 ligand. Because NK cells may promote tolerance by depleting antigen-presenting cells, we hypothesized improved outcomes for HLA-Bw4 recipients of HLA-Bw6 grafts. We evaluated differences in acute cellular rejection and CLAD-free survival across 252 KIR3DL1+ recipients from University of California, San Francisco (UCSF). For validation, we assessed survival and freedom from bronchiolitis obliterans syndrome (BOS), retransplantation, or death in 12 845 non-KIR typed recipients from the United Network for Organ Sharing (UNOS) registry. Cox proportional hazards models were adjusted for age, gender, ethnicity, transplant type, and HLA mismatching. HVG-capable subjects in the UCSF cohort had a decreased risk of CLAD or death (hazard ratio [HR] 0.57, 95% confidence interval [CI] 0.36–0.88) and decreased early lymphocytic bronchitis. The HVG effect was not significant in subjects with genotypes predicting low KIR3DL1 expression. In the UNOS cohort, HVG-capable subjects had a decreased risk of BOS, retransplant, or death (HR 0.95, 95% CI 0.91–0.99). Survival improved with the higher-affinity Bw4-80I ligand and in Bw4 homozygotes. Improved outcomes in HVG-capable recipients are consistent with a protective NK cell role. Augmentation of NK activity could supplement current immunosuppression techniques.
  • Blood Chimerism in Dizygotic Monochorionic Twins During 5 Years Observation
    Dizygotic monochorionic twin pregnancies can result in blood chimerism due to in utero twin-to-twin exchange of stem cells. In this case, we examined the proportion of allogeneic red blood cells by flow cytometry and the proportion of allogeneic nucleated cells by digital polymerase chain reaction at 7 months and again at 5 years. We found an increase in the proportion of allogeneic cells from 63% to 89% in one twin, and a similar increase in autologous cells in the other twin from 57% to 84%. A paradigm for stem cell therapy could be modeled on this case: induction of tolerance and chimerism by antenatal transfusion of donor stem cells. The procedure would hold the promise of transplantation and tolerance induction without myeloablative conditioning for inheritable benign hematological diseases such as sickle cell disease and thalassemia.
  • Prolonged Cold Ischemia Time Results in Local and Remote Organ Dysfunction in a Murine Model of Vascularized Composite Transplantation
    Vascularized composite allotransplantation (VCA) is a viable reconstructive option for complex tissue defects. Although grafts with a large muscular component may be uniquely susceptible to ischemia–reperfusion (I/R) syndrome, the safe cold ischemia time in VCA has not been established. We investigated the effects of cold ischemia on innate immune response and recipient survival in a murine orthotopic hindlimb transplantation model. Surprisingly, mice receiving grafts exposed to 6 h or longer of cold storage demonstrated reduced survival and massive elevations in serum creatinine, blood urea nitrogen, and creatine kinase, compared with 1 h of cold storage recipients. This was accompanied by progressive increase in macrophage and neutrophil cell infiltration in muscle biopsy specimens, altered platelet endothelial cell adhesion molecule-1 expression, and ultimate renal injury. Multiplex immunoassay analysis identified 21 cytokines in serum and 18 cytokines in muscle biopsy specimens that are likely essential in the complex response to I/R-triggered injury in VCA. In conclusion, this study, in a mouse model of orthotopic hindlimb transplantation, is the first to document that prolonged cold ischemia triggers progressive I/R injury with vascular endothelial damage and may lead to irrecoverable local and remote organ damage. These experimental findings are important in guiding future therapies for human VCA recipients.
  • Improved Time to Notification of Impending Brain Death and Increased Organ Donation Using an Electronic Clinical Decision Support System
    Early referral of patients to an organ procurement organization (OPO) may positively affect donation outcomes. We implemented an electronic clinic decision support (CDS) system to automatically notify our OPO of children meeting clinical triggers indicating impending brain death. Medical records of all patients who died in a pediatric critical care unit or were referred for imminent death for 3 years prior to installation of the initial CDS (pre-CDS) and for 1 year after implementation of the final CDS (post-CDS) were reviewed. Mean time to OPO notification decreased from 30.2 h pre-CDS to 1.7 h post-CDS (p = 0.015). Notification within 1 h of meeting criteria increased from 36% pre-CDS to 70% post-CDS (p = 0.003). Although an increase in donor conversion from 50% pre-CDS to 90% post-CDS did not reach statistical significance (p = 0.0743), there were more organ donors post-CDS (11 of 24 deaths) than pre-CDS (seven of 57 deaths; p = 0.002). Positive outcomes were achieved with the use of a fully automated CDS system while simultaneously realizing few false-positive notifications, low costs, and minimal workflow interruption. Use of an electronic CDS system in a pediatric hospital setting improved timely OPO notification and was associated with increased organ donation.
  • Uptake of Cancer Screening Tests Among Recipients of Solid Organ Transplantation
    Population-based cancer screening recommendations are also suggested for solid organ transplant recipients (SOTR); however, recommendation adherence is unknown. In a population-based cohort of SOTR in Ontario between 1997 and 2010, we determined the uptake of breast, cervical, and colorectal cancer screening tests and identified factors associated with up-to-date screening using recurrent event analysis. We identified 4436 SOTR eligible for colorectal, 2252 for cervical, and 1551 for breast cancer screening. Of those, 3437 (77.5%), 1572 (69.8%), and 1417 (91.4%), respectively, were not up-to-date for cancer screening tests during the observation period. However, these rates are likely an overestimate due to the inability to differentiate between tests done for screening or for diagnosis. SOTR with fewer comorbidities had higher rates of becoming screen up-to-date. Assessment by a primary care provider (PCP) was associated with becoming up-to-date with cancer screening (breast relative risk [RR] = 1.40, 95% confidence interval [CI]: 1.12–1.76, cervical RR = 1.29, 95% CI: 1.06–1.57, colorectal RR = 1.30, 95% CI: 1.15–1.48). Similar results were observed for continuity of care by transplant specialist at a transplant center. In conclusion, cancer screening for most SOTR does not adhere to standard recommendations. Involvement of PCPs in posttransplant care and continuity of care at a transplant center may improve the uptake of screening.
  • The Resurgence of Xenotransplantation
    There has been an upsurge of interest in xenotransplantation in recent years. This resurgence can attributed to a combination of factors. First, there has been a dramatic improvement in efficacy in several preclinical models, with maximum xenograft survival times increasing to 950 days for islets, 945 days for hearts, and 310 days for kidneys. Second, the rapid development of genome editing technology (particularly the advent of clustered regularly interspaced short palindromic repeats/Cas9) has revolutionized the capacity to generate new donor pigs with multiple protective genetic modifications; what once took many years to achieve can now be performed in months, with much greater precision and scope. Third, the specter of porcine endogenous retrovirus (PERV) has receded significantly. There has been no evidence of PERV transmission in clinical trials and preclinical models, and improved screening methods and new options for the treatment or even elimination of PERV are now available. Balancing these positive developments are several remaining challenges, notably the heavy and often clinically inapplicable immunosuppression required to prevent xenograft rejection. Nonetheless, the potential for xenotransplantation as a solution to the shortage of human organs and tissues for transplantation continues to grow.
  • Normothermic Ex Vivo Kidney Perfusion Following Static Cold Storage—Brief, Intermediate, or Prolonged Perfusion for Optimal Renal Graft Reconditioning?
    Normothermic ex vivo kidney perfusion (NEVKP) demonstrated superior results compared to hypothermic storage in donation after circulatory death (DCD) kidney transplantation. It is unknown whether an optimal perfusion time exists following hypothermic storage to allow for the recovery of renal grafts from cold ischemic injury. In a porcine model of DCD kidney autotransplantation, the impact of initial static cold storage (SCS) (8 h) followed by various periods of NEVKP recovery was investigated: group A, 8 hSCS only (control); group B, 8 hSCS + 1 hNEVKP (brief NEVKP); group C, 8 hSCS + 8 hNEVKP (intermediate NEVKP); and group D, 8 hSCS + 16 hNEVKP (prolonged NEVKP). All grafts were preserved and transplanted successfully. One animal in group D was sacrificed and excluded by postoperative day 3 due to hind limb paralysis, but demonstrated good renal function. Postoperative graft assessment during 8 days’ follow-up demonstrated lowest levels of peak serum creatinine for intermediate (C) and prolonged (D) NEVKP (p = 0.027). Histological assessment on day 8 demonstrated a significant difference in tubular injury (p = 0.001), with highest values for group B. These results suggest that longer periods of NEVKP following SCS are feasible and safe for postponing surgical transplant procedure and superior to brief NEVKP, reducing the damage caused during cold ischemic storage of renal grafts.
  • Incidence and Predictors of Cancer Following Kidney Transplantation in Childhood
    Cancer risk is increased substantially in adult kidney transplant recipients, but the long-term risk of cancer in childhood recipients is unclear. Using the Australian and New Zealand Dialysis and Transplant Registry, the authors compared overall and site-specific incidences of cancer after transplantation in childhood recipients with population-based data by using standardized incidence ratios (SIRs). Among 1734 childhood recipients (median age 14 years, 57% male, 85% white), 289 (16.7%) developed cancer (196 nonmelanoma skin cancers, 143 nonskin cancers) over a median follow-up of 13.4 years. The 25-year cumulative incidences of any cancer were 27% (95% confidence intervals 24–30%), 20% (17–23%) for nonmelanoma skin cancer, and 14% (12–17%) for nonskin cancer (including melanoma). The SIR for nonskin cancer was 8.23 (95% CI 6.92–9.73), with the highest risk for posttransplant lymphoproliferative disease (SIR 45.80, 95% CI 32.71–62.44) and cervical cancer (29.4, 95% CI 17.5–46.5). Increasing age at transplantation (adjusted hazard ratio [aHR] per year 1.10, 95% CI 1.06–1.14), white race (aHR 3.36, 95% CI 1.61–6.79), and having a functioning transplant (aHR 2.27, 95% CI 1.47–3.71) were risk factors for cancer. Cancer risk, particularly for virus-related cancers, is increased substantially after kidney transplantation during childhood.
  • Novel Magnetic Resonance Imaging for Assessment of Bronchial Stenosis in Lung Transplant Recipients
    Bronchial stenosis in lung transplant recipients is a common disorder that adversely affects clinical outcomes. It is evaluated by spirometry, CT scanning, and bronchoscopy with significant limitations. We hypothesize that MRI using both ultrashort echo time (UTE) scans and hyperpolarized (HP) 129Xe gas can offer structural and functional assessment of bronchial stenosis seen after lung transplantation. Six patients with lung transplantation–related bronchial stenosis underwent HP 129Xe MRI and UTE MRI in the same session. Three patients subsequently underwent airway stent placement and had repeated MRI at 4-week follow-up. HP 129Xe MRI depicted decreased ventilation distal to the stenotic airway. After airway stent placement, MRI showed that low-ventilation regions had decreased (35% vs. 27.6%, p = 0.006) and normal-ventilation regions had increased (17.9% vs. 27.6%, p = 0.04) in the stented lung. Improved gas transfer was also seen on 129Xe MRI. There was a good correlation between UTE MRI and independent bronchoscopic airway diameter assessment (Pearson correlation coefficient = 0.92). This pilot study shows that UTE and HP 129Xe MRI are feasible in patients with bronchial stenosis related to lung transplantation and may provide structural and functional airway assessment to guide treatment. These conclusions need to be confirmed with larger studies.
  • Geographic Disparities in Liver Availability: Accidents of Geography, or Consequences of Poor Social Policy?
    Recently, a redistricting proposal intended to equalize Model for End-stage Liver Disease score at transplant recommended expanding liver sharing to mitigate geographic variation in liver transplantation. Yet, it is unclear whether variation in liver availability is arbitrary and a disparity requiring rectification or reflects differences in access to care. We evaluate the proposal's claim that organ supply is an “accident of geography” by examining the relationship between local organ supply and the uneven landscape of social determinants and policies that contribute to differential death rates across the United States. We show that higher mortality leading to greater availability of organs may in part result from disproportionate risks incurred at the local level. Disparities in public safety laws, health care infrastructure, and public funding may influence the risk of death and subsequent availability of deceased donors. These risk factors are disproportionately prevalent in regions with high organ supply. Policies calling for organ redistribution from high-supply to low-supply regions may exacerbate existing social and health inequalities by redistributing the single benefit (greater organ availability) of greater exposure to environmental and contextual risks (e.g. violent death, healthcare scarcity). Variation in liver availability may not be an “accident of geography” but rather a byproduct of disadvantage.
  • BK Virus Nephropathy: Histological Evolution by Sequential Pathology
    Reactivation of BK virus in renal allografts causes a destructive chronic infection. This single-center retrospective cohort study describes the evolution of BK virus allograft nephropathy (BKVAN) from 63 kidneys (from 61 patients) using sequential histopathology (454 biopsies, averaging 7.8 ± 2.6 per kidney) followed for 60.1 mo. Uninfected protocol biopsies formulated time-matched control Banff scores (n = 975). Interstitial inflammation occurred in 73% at diagnosis, correlating with viral histopathology (r = 0.413, p = 0.008) and amplifying early injury with accelerated interstitial fibrosis and tubular atrophy (IF/TA, p = 0.017) by 3 mo. Prodromal simian virus 40 large T antigen (SV40T)–negative inflammation with viremia preceded the histological diagnosis in 23.8%. Persistent subacute injury from viral cytopathic effect was associated with acute tubular necrosis and ongoing interstitial inflammation, culminating in IF/TA in 86.9%. Overall, cellular interstitial infiltration mitigated the intensity of subsequent tubular injury, SV40T, and tissue viral load, assessed by sequential paired histology (p < 0.001). Graft loss was predicted by high-level viremia (hazard ratio [HR] 4.996, 95% CI 2.19–11.396, p < 0.001), deceased donor (HR 3.201, 95% CI 1.149–8.915, p = 0.026), and late acute rejection (HR 3.124, 95% CI 1.037–9.413, p = 0.043). Transplant failure occurred in 38.1%, with uncontrolled infection (58.3%) and SV40T-negative chronic rejection (41.7%) causing losses. BKVAN is characterized by subacute virus-induced tubular injury, inflammation, and progressive nephron destruction. Effective antiviral therapy remains an unmet clinical need.
  • Cum hoc sed non propter hoc
  • A Memory B Cell Crossmatch Assay for Quantification of Donor-Specific Memory B Cells in the Peripheral Blood of HLA-Immunized Individuals
    Humoral responses against mismatched donor HLA are routinely measured as serum HLA antibodies, which are mainly produced by bone marrow–residing plasma cells. Individuals with a history of alloimmunization but lacking serum antibodies may harbor circulating dormant memory B cells, which may rapidly become plasma cells on antigen reencounter. Currently available methods to detect HLA-specific memory B cells are scarce and insufficient in quantifying the complete donor-specific memory B cell response due to their dependence on synthetic HLA molecules. We present a highly sensitive and specific tool for quantifying donor-specific memory B cells in peripheral blood of individuals using cell lysates covering the complete HLA class I and class II repertoire of an individual. Using this enzyme-linked immunospot (ELISpot) assay, we found a median frequency of 31 HLA class I and 89 HLA class II–specific memory B cells per million IgG-producing cells directed at paternal HLA in peripheral blood samples from women (n = 22) with a history of pregnancy, using cell lysates from spouses. The donor-specific memory B cell ELISpot can be used in HLA diagnostic laboratories as a cross-match assay to quantify donor-specific memory B cells in patients with a history of sensitizing events.
  • B Cell Receptor Genes Associated With Tolerance Identify a Cohort of Immunosuppressed Patients With Improved Renal Allograft Graft Function
    We previously reported that two B cell receptor genes, IGKV1D-13 and IGKV4-1, were associated with tolerance following kidney transplantation. To assess the potential utility of this “signature,” we conducted a prospective, multicenter study to determine the frequency of patients predicted tolerant within a cohort of patients deemed to be candidates for immunosuppressive minimization. At any single time point, 25–30% of patients were predicted to be tolerant, while 13.7% consistently displayed the tolerance “signature” over the 2-year study. We also examined the relationship of the presence of the tolerance “signature” on drug use and graft function. Contrary to expectations, the frequency of predicted tolerance was increased in patients receiving tacrolimus and reduced in those receiving corticosteroids, mycophenolate mofetil, or Thymoglobulin as induction. Surprisingly, patients consistently predicted to be tolerant displayed a statistically and clinically significant improvement in estimated glomerular filtration rate that increased over time following transplantation. These findings indicate that the frequency of patients consistently predicted to be tolerant is sufficiently high to be clinically relevant and confirm recent findings by others that immunosuppressive agents impact putative biomarkers of tolerance. The association of a B cell–based “signature” with graft function suggests that B cells may contribute to the function/survival of transplanted kidneys.
  • Chronic Allograft Deterioration: A Clinical Reality in Vascularized Composite Allotransplantation
  • The Influence of End-of-Life Care on Organ Donor Potential
    Many patients with acute devastating brain injury die outside intensive care units and could go unrecognized as potential organ donors. We conducted a prospective observational study in seven hospitals in the Netherlands to define the number of unrecognized potential organ donors outside intensive care units, and to identify the effect that end-of-life care has on organ donor potential. Records of all patients who died between January 2013 and March 2014 were reviewed. Patients were included if they died within 72 h after hospital admission outside the intensive care unit due to devastating brain injury, and fulfilled the criteria for organ donation. Physicians of included patients were interviewed using a standardized questionnaire regarding logistics and medical decisions related to end-of-life care. Of the 5170 patients screened, we found 72 additional potential organ donors outside intensive care units. Initiation of end-of-life care in acute settings and lack of knowledge and experience in organ donation practices outside intensive care units can result in under-recognition of potential donors equivalent to 11–34% of the total pool of organ donors. Collaboration with the intensive care unit and adjusting the end-of-life path in these patients is required to increase the likelihood of organ donation.
  • Urinary Markers of Fibrosis and Risk of Cardiovascular Events and Death in Kidney Transplant Recipients: The FAVORIT Trial
    Cardiovascular risk remains high in kidney transplant recipients (KTRs) despite improved kidney function after transplant. Urinary markers of kidney fibrosis and injury may help to reveal mechanisms of this risk. In a case–cohort study among stable KTRs who participated in the FAVORIT trial, we measured four urinary proteins known to correlate with kidney tubulointerstitial fibrosis on biopsy (urine alpha 1 microglobulin [α1m], monocyte chemoattractant protein-1 [MCP-1], procollagen type I [PINP] and type III [PIIINP] N-terminal amino peptide) and evaluated associations with cardiovascular disease (CVD) events (n = 300) and death (n = 371). In adjusted models, higher urine α1m (hazard ratio [HR] per doubling of biomarker 1.40 [95% confidence interval [CI] 1.21, 1.62]), MCP-1 (HR 1.18 [1.03, 1.36]), and PINP (HR 1.13 [95% CI 1.03, 1.23]) were associated with CVD events. These three markers were also associated with death (HR per doubling α1m 1.51 [95% CI 1.32, 1.72]; MCP-1 1.31 [95% CI 1.13, 1.51]; PINP 1.11 [95% CI 1.03, 1.20]). Higher concentrations of urine α1m, MCP-1, and PINP may identify KTRs at higher risk for CVD events and death. These markers may identify a systemic process of fibrosis involving both the kidney and cardiovascular system, and give new insights into mechanisms linking the kidney with CVD.
  • Cytoprotective and Antioxidant Effects of Steen Solution on Human Lung Spheroids and Human Endothelial Cells
    Respiratory diseases represent a major healthcare burden worldwide. Lung transplantation (LTx) is the “gold standard” for end-stage patients, strongly limited by shortage of available/suitable donor lungs. Normothermic ex vivo lung perfusion (EVLP) has significantly increased the number of lungs suitable for transplantation. Steen solution is used for EVLP, but the mechanisms involved in its beneficial properties remain to be clarified. We investigated the effects of Steen solution in an in vitro protocol of cold starvation and normothermic recovery on human lung spheroids, named pneumospheres (PSs), containing epithelial/basal cells, and on endothelial human umbilical vein endothelial cells (HUVEC). Steen solution significantly preserved the viability of PSs, reduced reactive oxygen species (ROS) release by PSs and HUVECs, decreased NADPH-oxidase (NOX) activity in PSs, and reduced inflammatory cytokines expression levels in HUVECs. Steen solution was able to specifically reduce NADPH oxidase 2 (NOX2) isoform activation, particularly in PSs, as detected by soluble-NOX2 peptide and p47-phosphorylation. Interestingly, a specific NOX2 inhibitor could partly mimic the pro-survival effect of Steen on PSs. We provide the first evidence that Steen solution can preserve lung epithelial/progenitor cells viability partially through NOX2 downregulation, and exert antioxidant effects on parenchymal cells, with consequent ROS reduction. These results suggest that NOX2 inhibition might be an additional strategy to reduce cellular damage during LTx procedures.
  • BK Polyomavirus-Specific 9mer CD8 T Cell Responses Correlate With Clearance of BK Viremia in Kidney Transplant Recipients: First Report From the Swiss Transplant Cohort Study
    BK polyomavirus (BKPyV) causes premature kidney transplant (KT) failure in 1–15% of patients. Because antivirals are lacking, most programs screen for BKPyV-viremia and, if positive, reduce immunosuppression. To evaluate the relationship of viremia and BKPyV-specific immunity, we examined prospectively cryopreserved plasma and peripheral blood mononuclear cells at the time of transplantation (T0) and at 6 mo (T6) and 12 mo (T12) after transplant from 28 viremic KT patients and 68 nonviremic controls matched for the transplantation period. BKPyV IgG seroprevalence was comparable between cases (89.3%) and controls (91.2%; p = 0.8635), but cases had lower antibody levels (p = 0.022) at T0. Antibody levels increased at T6 and T12 but were not correlated with viremia clearance. BKPyV-specific T cell responses to pools of overlapping 15mers (15mer peptide pool [15mP]) or immunodominant CD8 9mers (9mer peptide pool [9mP]) from the early viral gene region were not different between cases and controls at T0; however, clearance of viremia was associated with stronger 9mP responses at T6 (p = 0.042) and T12 (p = 0.048), whereas 15mP responses were not informative (T6 p = 0.359; T12 p = 0.856). BKPyV-specific T cells could be expanded in vitro from all patients after transplant, permitting identification of 78 immunodominant 9mer epitopes including 50 new ones across different HLA class I. Thus, 9mP-responses may be a novel marker of reconstituting CD8 T cell function that warrants further study as a complement of plasma BKPyV loads for guiding immunosuppression reduction.
  • Pretransplant Numbers of CD16+ Monocytes as a Novel Biomarker to Predict Acute Rejection After Kidney Transplantation: A Pilot Study
    Acute rejection is one of the major immunological determinants of kidney graft function and survival. Early biomarkers to predict rejection are lacking. Emerging evidence reveals a crucial role for the monocyte/macrophage lineage cells in the pathogenesis of rejection. We hypothesized that higher pretransplant numbers of proinflammatory CD16+ monocytes can predict rejection. The study cohort consisted of 104 kidney transplant recipients (58 with no rejection and 46 with biopsy-proven rejection) and 33 healthy persons. Posttransplant median follow-up time was 14.7 mo (interquartile range 0.3–34 mo). Pretransplantation blood samples were analyzed by flow cytometry for monocyte immunophenotypes. Groups were compared by Cox regression models for the occurrence of acute rejection. We documented a significantly increased absolute number of pretransplant CD16+ monocytes in patients who developed biopsy-proven rejection after transplantation compared with those with no rejection (hazard ratio [HR] 1.60, 95% CI 1.28–2.00, p < 0.001) and healthy persons (HR 1.47, 95% CI 1.18–1.82, p < 0.001). In parallel, significantly fewer absolute numbers of CD16− monocytes were observed at pretransplant time points in rejectors versus nonrejectors (HR 0.74, 95% CI 0.58–0.94, p < 0,014). A higher pretransplant number of CD16+ monocytes is significantly associated with a higher risk of acute rejection after kidney transplantation.
  • The Medication Level Variability Index (MLVI) Predicts Poor Liver Transplant Outcomes: A Prospective Multi-Site Study
    Nonadherence to immunosuppressant medications is a leading cause of poor long-term outcomes in transplant recipients. The Medication Level Variability Index (MLVI) provides a vehicle for transplant outcome risk-stratification through continuous assessment of adherence. The MALT (Medication Adherence in children who had a Liver Transplant) prospective multi-site study evaluated whether MLVI predicts late acute rejection (LAR). Four hundred pediatric (1–17-year-old) liver transplant recipients were enrolled and followed for 2 years. The a-priori hypothesis was that a higher MLVI predicts LAR. Predefined secondary analyses evaluated other outcomes such as liver enzyme levels, and sensitivity analyses compared adolescents to pre-adolescents. In the primary analysis sample of 379 participants, a higher prerejection MLVI predicted LAR (mean prerejection MLVI with LAR: 2.4 [3.6 standard deviation] versus without LAR, 1.6 [1.1]; p = 0.026). Fifty-three percent of the adolescents with MLVI>2 in year 1 had LAR by the end of year 2, as compared with 6% of those with year 1 MLVI≤2. A higher MLVI was significantly associated with all secondary outcomes. MLVI, a marker of medication adherence that uses clinically derived information, predicts LAR in pediatric liver transplant recipients.
  • Reciprocity to Increase Participation of Compatible Living Donor and Recipient Pairs in Kidney Paired Donation
    Inclusion of compatible living donor and recipient pairs (CPs) in kidney paired donation (KPD) programs could increase living donor transplantation. We introduce the concept of a reciprocity-based strategy in which the recipient of a CP who participates in KPD receives priority for a repeat deceased donor transplant in the event their primary living donor KPD transplant fails, and then we review the practical and ethical considerations of this strategy. The strategy limits prioritization to CPs already committed to living donation, minimizing the risk of unduly influencing donor behavior. The provision of a tangible benefit independent of the CP's actual KPD match avoids many of the practical and ethical challenges with strategies that rely on finding the CP recipient a better-matched kidney that might provide the CP recipient a future benefit to increase KPD participation. Specifically, the strategy avoids the potential to misrepresent the degree of future benefit of a better-matched kidney to the CP recipient and minimizes delays in transplantation related to finding a better-matched kidney. Preliminary estimates suggest the strategy has significant potential to increase the number of living donor transplants. Further evaluation of the acceptance of this strategy by CPs and by waitlisted patients is warranted.
  • Comment on the Article “OPTN/SRTR 2015 Annual Data Report: Pancreas”
  • Cytotoxicity of Natural Killer Cells Activated Through NKG2D Contributes to the Development of Bronchiolitis Obliterans in a Murine Heterotopic Tracheal Transplant Model
    Bronchiolitis obliterans after lung transplantation is a major cause of postoperative mortality in which T cell–mediated immunity is known to play an important role. However, the exact contribution of natural killer (NK) cells, which have functions similar to CD8+ T cells, has not been defined. Here, we assessed the role of NK cells in murine bronchiolitis obliterans through heterotopic tracheal transplantations and found a greater percentage of NK cells in allografts than in isografts. Depletion of NK cells using an anti-NK1.1 antibody attenuated bronchiolitis obliterans in transplant recipients compared with controls. In terms of NK cell effector functions, an improvement in bronchiolitis obliterans was observed in perforin-KO recipient mice compared to wild type (WT). Furthermore, we found upregulation of NKG2D-ligand in allografts and demonstrated the significance of this using grafts expressing Rae-1, a murine NKG2D-ligand, which induced severe bronchiolitis obliterans in WT and Rag-1 KO recipients. This effect was ameliorated by injection of anti-NKG2D blocking antibody. Together, these results suggest that cytotoxicity resulting from activation of NK cells through NKG2D leads to the development of murine bronchiolitis obliterans.
  • Hemodialysis Clinic Social Networks, Sex Differences, and Renal Transplantation
    This study describes patient social networks within a new hemodialysis clinic and models the association between social network participation and kidney transplantation. Survey and observational data collected between August 2012 and February 2015 were used to observe the formation of a social network of 46 hemodialysis patients in a newly opened clinic. Thirty-two (70%) patients formed a social network, discussing health (59%) and transplantation (44%) with other patients. While transplant-eligible women participated in the network less often than men (56% vs. 90%, p = 0.02), women who participated discussed their health more often than men (90% vs. 45.5%, p = 0.02). Patients in the social network completed a median of two steps toward transplantation compared with a median of 0 for socially isolated patients (p = 0.003). Patients also completed more steps if network members were closely connected (β = 2.23, 95% confidence interval [CI] 0.16–4.29, p = 0.03) and if network members themselves completed more steps (β = 2.84, 95% CI 0.11–5.57, p = 0.04). The hemodialysis clinic patient social network had a net positive effect on completion of transplant steps, and patients who interacted with each other completed a similar number of steps.
  • Nosocomial BK Polyomavirus Infection Causing Hemorrhagic Cystitis Among Patients With Hematological Malignancies After Hematopoietic Stem Cell Transplantation
    BK polyomavirus (BKPyV) is recognized as a pathogen that causes diseases such as hemorrhagic cystitis and nephritis after allogeneic hematopoietic stem cell transplantation (HSCT) or renal transplantation. BKPyV-associated disease is thought to occur through reactivation under immunosuppression. However, the possibility of its nosocomial transmission and the clinical significance of such transmission have not been elucidated. During a 6-month period, nine adult patients (median age: 47 years) who had hematological disorders and who were treated with HSCT (n = 7) or chemotherapy (n = 2) in a single hematology department developed hemorrhagic cystitis due to BKPyV infection. The polymerase chain reaction products of BKPyV DNA obtained from each patient were sequenced. Of the nine patients, six had subtype I, 2 had subtype IV, and 1 had subtype II or III. In the alignment of sequences, four and two of the six subtype I strains were completely homologous (100%). These results strongly suggest that BKPyV has the potential to cause nosocomial infection within a medical facility, especially among recipients of HSCT. Further studies are clearly warranted to elucidate the route(s) of BKPyV transmission in order to establish optimal infection control.
  • Novel Application of Localized Nanodelivery of Anti–Interleukin-6 Protects Organ Transplant From Ischemia–Reperfusion Injuries
    Ischemia–reperfusion injury (IRI) evokes intragraft inflammatory responses, which markedly augment alloimmune responses against the graft. Understanding the mechanisms underlying these responses is fundamental to develop therapeutic regimens to prevent/ameliorate organ IRI. Here, we demonstrate that IRI results in a marked increase in mitochondrial damage and autophagy in dendritic cells (DCs). While autophagy is a survival mechanism for ischemic DCs, it also augments their production of interleukin (IL)-6. Allograft-derived dendritic cells (ADDCs) lacking autophagy-related gene 5 (Atg5) showed higher death rates posttransplantation. Transplanted ischemic hearts from CD11cCre/Atg5 conditional knockout mice showed marked reduction in intragraft expression of IL-6 compared with controls. To antagonize the effect of IL-6 locally in the heart, we synthesized novel anti–IL-6 nanoparticles with capacity for controlled release of anti–IL-6 over time. Compared with systemic delivery of anti–IL-6, localized delivery of anti–IL-6 significantly reduced chronic rejection with a markedly lower amount administered. Despite improved allograft histology, there were no changes to splenic T cell populations, illustrating the importance of local IL-6 in driving chronic rejection after IRI. These data carry potential clinical significance by identifying an innovative, targeted strategy to manipulate organs before transplantation to diminish inflammation, leading to improved long-term outcomes.
  • Response to “Normothermic Machine Perfusion: A New World Deserving Careful Exploration”
  • “White-Out” After Lung Transplantation: A Multicenter Cohort Description of Late Acute Graft Failure
    Graft failure represents a leading cause of mortality after organ transplantation. Acute late-onset graft failure has not been widely reported. The authors describe the demographics, CT imaging–pathology findings, and treatment of patients presenting with the latter. A retrospective review was performed of lung transplant recipients at two large-volume centers. Acute late-onset graft failure was defined as sudden onset of bilateral infiltrates with an oxygenation index <200 without identifiable cause or concurrent extrapulmonary organ failure. Laboratory, bronchoalveolar lavage (BAL), radiology, and histology results were assessed. Between 2005 and 2016, 21 patients were identified. Median survival was 19 (IQR 13–36) days post onset. Twelve patients (57%) required intensive care support at onset, 12 (57%) required mechanical ventilation, and 6 (29%) were placed on extracorporeal life support. Blood and BAL analysis revealed elevated neutrophilia, with CT demonstrating diffuse ground-glass opacities. Transbronchial biopsy samples revealed acute fibrinoid organizing pneumonia (AFOP), organizing pneumonia, and diffuse alveolar damage (DAD). Assessment of explanted lungs confirmed AFOP and DAD but also identified obliterative bronchiolitis. Patients surviving to discharge without redo transplantation (n = 2) subsequently developed restrictive allograft syndrome. This study describes acute late-onset graft failure in lung allograft recipients, without known cause, which is associated with a dismal prognosis.
  • Safety and Outcomes in 100 Consecutive Donation After Circulatory Death Liver Transplants Using a Protocol That Includes Thrombolytic Therapy
    Donation after circulatory death (DCD) liver transplantation (LT) reportedly yields inferior survival and increased complication rates compared with donation after brain death (DBD). We compare 100 consecutive DCD LT using a protocol that includes thrombolytic therapy (late DCD group) to an historical DCD group (early DCD group n = 38) and a cohort of DBD LT recipients (DBD group n = 435). Late DCD LT recipients had better 1- and 3-year graft survival rates than early DCD LT recipients (92% vs. 76.3%, p = 0.03 and 91.4% vs. 73.7%, p = 0.01). Late DCD graft survival rates were comparable to those of the DBD group (92% vs. 93.3%, p = 0.24 and 91.4% vs. 88.2%, p = 0.62). Re-transplantation occurred in 18.4% versus 1% for the early and late DCD groups, respectively (p = 0.001). Patient survival was similar in all three groups. Ischemic-type biliary lesions (ITBL) occurred in 5%, 3%, and 0.2% for early DCD, late DCD, and DBD groups, respectively, but unlike in the early DCD group, in the late DCD group ITBL was endoscopically managed and resolved in each case. Using a protocol that includes a thrombolytic therapy, DCD LT yielded patient and graft survival rates comparable to DBD LT.
  • Complement Alternative Pathway Deficiency in Recipients Protects Kidney Allograft From Ischemia/Reperfusion Injury and Alloreactive T Cell Response
    Despite the introduction of novel and more targeted immunosuppressive drugs, the long-term survival of kidney transplants has not improved satisfactorily. Early antigen-independent intragraft inflammation plays a critical role in the initiation of the alloimmune response and impacts long-term graft function. Complement activation is a key player both in ischemia/reperfusion injury (IRI) as well as in adaptive antigraft immune response after kidney transplantation. Since the alternative pathway (AP) amplifies complement activation regardless of the initiation pathways and renal IR injured cells undergo uncontrolled complement activation, we speculated whether selective blockade of AP could be a strategy for prolonging kidney graft survival. Here we showed that Balb/c kidneys transplanted in factor b deficient C57 mice underwent reduced IRI and diminished T cell–mediated rejection. In in vitro studies, we found that fb deficiency in T cells and dendritic cells conferred intrinsic impaired alloreactive/allostimulatory functions, respectively, both in direct and indirect pathways of alloantigen presentation. By administering anti-fB antibody to C57 wt recipients in the early post Balb/c kidney transplant phases, we documented that inhibition of AP during both ischemia/reperfusion and early adaptive immune response is necessary for prolonging graft survival. These findings may have implication for the use of AP inhibitors in clinical kidney transplantation.
  • Origin of Enriched Regulatory T Cells in Patients Receiving Combined Kidney–Bone Marrow Transplantation to Induce Transplantation Tolerance
    We examined tolerance mechanisms in patients receiving HLA-mismatched combined kidney–bone marrow transplantation (CKBMT) that led to transient chimerism under a previously published nonmyeloablative conditioning regimen (Immune Tolerance Network study 036). Polychromatic flow cytometry and high-throughput sequencing of T cell receptor-β hypervariable regions of DNA from peripheral blood regulatory T cells (Tregs) and CD4 non-Tregs revealed marked early enrichment of Tregs (CD3+CD4+CD25highCD127lowFoxp3+) in blood that resulted from peripheral proliferation (Ki67+), possibly new thymic emigration (CD31+), and, in one tolerant subject, conversion from non-Tregs. Among recovering conventional T cells, central memory CD4+ and CD8+ cells predominated. A large proportion of the T cell clones detected in posttransplantation biopsy specimens by T cell receptor sequencing were detected in the peripheral blood and were not donor-reactive. Our results suggest that enrichment of Tregs by new thymic emigration and lymphopenia-driven peripheral proliferation in the early posttransplantation period may contribute to tolerance after CKBMT. Further, most conventional T cell clones detected in immunologically quiescent posttransplantation biopsy specimens appear to be circulating cells in the microvasculature rather than infiltrating T cells.
  • Chemotherapy and Transplantation: The Role of Immunosuppression in Malignancy and a Review of Antineoplastic Agents in Solid Organ Transplant Recipients
    It is estimated that solid organ transplant recipients have a two- to fourfold greater overall risk of malignancy than the general population. Some of the most common malignancies after transplant include skin cancers and posttransplant lymphoproliferative disorder. In addition to known risk factors such as environmental exposures, genetics, and infection with oncogenic viruses, immunosuppression plays a large role in the development of cancer through the loss of the immunosurveillance process. The purpose of this article is to explain the role of immunosuppression in cancer and to review the classes of chemotherapeutics. The field of anticancer drugs is continually expanding and developing, with limited data on use in transplant recipients. This article aims to provide information on class review, adverse effects, dose adjustments, and drug interactions that are pertinent to the care of transplant recipients.
  • Cancer in Solid Organ Transplant Recipients: There Is Still Much to Learn and Do
  • Determinants of the Magnitude of Interaction Between Tacrolimus and Voriconazole/Posaconazole in Solid Organ Recipients
    Administration of azole antifungals to tacrolimus-treated solid organ recipients results in a major drug–drug interaction characterized by increased exposure to tacrolimus. The magnitude of this interaction is highly variable but cannot currently be predicted. We performed a retrospective analysis of 126 solid organ recipients (95 lung, 31 kidney) co-treated with tacrolimus and voriconazole (n = 100) or posaconazole (n = 26). Predictors of the change in tacrolimus dose-corrected trough concentrations (C/D) between baseline and tacrolimus–azole co-therapy were assessed using linear mixed modeling. Patients were genotyped for relevant polymorphisms in CYP3A4, CYP3A5, MDR1, CYP2C19, POR, and UGT1A4. Tacrolimus C/D increased by a factor 5.0 ± 2.7 (range 1.0–20.2) for voriconazole and 4.4 ± 2.6 (range 0.9–18.0) for posaconazole, suggesting that a 66% dose reduction is insufficient for the majority of patients. Change in C/D was blunted in CYP3A5 expressors (estimated effect: -43%, p = 0.017) and affected by hematocrit (+8% per %, p = 0.004), baseline C/D (-14% per 100% increase, p < 0.001), and age (+1%, p = 0.008). However, the final model explained only 22% of interindividual variability in C/D change. In conclusion, CYP3A5 genotype and several clinical variables were identified as modulators of the tacrolimus–azole interaction, but these did not permit accurate predictions in individual patients.
  • Laparoscopic Biopsies in Pancreas Transplantation
    As there is no precise laboratory test or imaging study for detection of pancreas allograft rejection, there is increasing interest in obtaining pancreas tissue for diagnosis. Pancreas allograft biopsies are most commonly performed percutaneously, transcystoscopically, or endoscopically, yet pancreas transplant surgeons often lack the skills to perform these types of biopsies. We have performed 160 laparoscopic pancreas biopsies in 95 patients. There were 146 simultaneous kidney–pancreas biopsies and 14 pancreas-only biopsies due to pancreas alone, kidney loss, or extraperitoneal kidney. Biopsies were performed for graft dysfunction (89) or per protocol (71). In 13 cases, an additional laparoscopic procedure was performed at the same operation. The pancreas diagnostic tissue yield was 91.2%; however, the pancreas could not be visualized in eight cases (5%) and in 6 cases the tissue sample was nondiagnostic (3.8%). The kidney tissue yield was 98.6%. There were four patients with intraoperative complications requiring laparotomy (2.5%) with two additional postoperative complications. Half of all these complications were kidney related. There were no episodes of pancreatic enzyme leak and there were no graft losses related to the procedure. We conclude that laparoscopic kidney and pancreas allograft biopsies can be safely performed with very high tissue yields.
  • Mortality Risk Factors Among Patients With Cirrhosis and a Low Model for End-Stage Liver Disease Sodium Score (≤15): An Analysis of Liver Transplant Allocation Policy Using Aggregated Electronic Health Record Data
    Although the Model for End-Stage Liver Disease sodium (MELD Na) score is now used for liver transplant allocation in the United States, mortality prediction may be underestimated by the score. Using aggregated electronic health record data from 7834 adult patients with cirrhosis, we determined whether the cause of cirrhosis or cirrhosis complications was associated with an increased risk of death among patients with a MELD Na score ≤15 and whether patients with the greatest risk of death could benefit from liver transplantation (LT). Over median follow-up of 2.3 years, 3715 patients had a maximum MELD Na score ≤15. Overall, 3.4% were waitlisted for LT. Severe hypoalbuminemia, hepatorenal syndrome, and hepatic hydrothorax conferred the greatest risk of death independent of MELD Na score with 1-year predicted mortality >14%. Approximately 10% possessed these risk factors. Of these high-risk patients, only 4% were waitlisted for LT, despite no difference in nonliver comorbidities between waitlisted patients and those not listed. In addition, risk factors for death among waitlisted patients were the same as those for patients not waitlisted, although the effect of malnutrition was significantly greater for waitlisted patients (hazard ratio 8.65 [95% CI 2.57–29.11] vs. 1.47 [95% CI 1.08–1.98]). Using the MELD Na score for allocation may continue to limit access to LT.
  • Orthogonal Comparison of Molecular Signatures of Kidney Transplants With Subclinical and Clinical Acute Rejection: Equivalent Performance Is Agnostic to Both Technology and Platform
    We performed orthogonal technology comparisons of concurrent peripheral blood and biopsy tissue samples from 69 kidney transplant recipients who underwent comprehensive algorithm-driven clinical phenotyping. The sample cohort included patients with normal protocol biopsies and stable transplant (sTx) function (n = 25), subclinical acute rejection (subAR, n = 23), and clinical acute rejection (cAR, n = 21). Comparisons between microarray and RNA sequencing (RNA-seq) signatures were performed and demonstrated a strong correlation between the blood and tissue compartments for both technology platforms. A number of shared differentially expressed genes and pathways between subAR and cAR in both platforms strongly suggest that these two clinical phenotypes form a continuum of alloimmune activation. SubAR is associated with fewer or less expressed genes than cAR in blood, whereas in biopsy tissues, this clinical phenotype demonstrates a more robust molecular signature for both platforms. The discovery work done in this study confirms a clear ability to detect gene expression profiles for sTx, subAR, and cAR in both blood and biopsy tissue, yielding equivalent predictive performance that is agnostic to both technology and platform. Our data also provide strong biological insights into the molecular mechanisms underlying these signatures, underscoring their logistical potential as molecular diagnostics to improve clinical outcomes following kidney transplantation.
  • Effect of the Anti-C1s Humanized Antibody TNT009 and Its Parental Mouse Variant TNT003 on HLA Antibody–Induced Complement Activation—A Preclinical In Vitro Study
    The classic pathway (CP) of complement is believed to significantly contribute to alloantibody-mediated transplant injury, and targeted complement inhibition is currently considered to be a promising approach for preventing rejection. Here, we investigated the mode of action and efficacy of the humanized anti-C1s monoclonal antibody TNT009 and its parental mouse variant, TNT003, in preclinical in vitro models of HLA antibody–triggered CP activation. In flow cytometric assays, we measured the attachment of C1 subcomponents and C4/C3 split products (C4b/d, C3b/d) to HLA antigen–coated flow beads or HLA-mismatched aortic endothelial cells and splenic lymphocytes. Anti-C1s antibodies profoundly inhibited C3 activation at concentrations >20 μg/mL, in both solid phase and cellular assays. While C4 activation was also prevented, this was not the case for C1 subcomponent attachment. Analysis of serum samples obtained from 68 sensitized transplant candidates revealed that the potency of inhibition was related to the extent of baseline CP activation. This study demonstrates that anti-C1s antibodies TNT009 and TNT003 are highly effective in blocking HLA antibody–triggered complement activation downstream of C1. Our results provide the foundation for clinical studies designed to investigate the potential of TNT009 in the treatment or prevention of complement-mediated tissue injury in sensitized transplant recipients.
  • Filtration Markers, Cardiovascular Disease, Mortality, and Kidney Outcomes in Stable Kidney Transplant Recipients: The FAVORIT Trial
    Cystatin C and beta-2-microglobulin (B2M) are filtration markers associated with adverse outcomes in nontransplant populations, sometimes with stronger associations than for creatinine. We evaluated associations of estimated glomerular filtration rate from cystatin C (eGFRcys), B2M (eGFRB2M), and creatinine (eGFRcr) with cardiovascular outcomes, mortality, and kidney failure in stable kidney transplant recipients using a case–cohort study nested within the Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) Trial. A random subcohort was selected (N = 508; mean age 51.6 years, median transplant vintage 4 years, 38% women, 23.6% nonwhite race) with enrichment for cardiovascular events (N = 306; 54 within the subcohort), mortality (N = 208; 68 within the subcohort), and kidney failure (N = 208; 52 within the subcohort). Mean eGFRcr, eGFRcys, and eGFRB2M were 46.0, 43.8, and 48.8 mL/min/1.73m2, respectively. After multivariable adjustment, hazard ratios for eGFRcys and eGFRB2M <30 versus 60+ were 2.02 (95% confidence interval [CI] 1.09–3.76; p = 0.03) and 2.56 (1.35–4.88; p = 0.004) for cardiovascular events; 3.92 (2.11–7.31) and 4.09 (2.21–7.54; both p < 0.001) for mortality; and 9.49 (4.28–21.00) and 15.53 (6.99–34.51; both p < 0.001) for kidney failure. Associations persisted with additional adjustment for baseline eGFRcr. We conclude that cystatin C and B2M are strongly associated with cardiovascular events, mortality, and kidney failure in stable kidney transplant recipients.
  • Radiological Analysis of Unused Donor Lungs: A Tool to Improve Donor Acceptance for Transplantation?
    Despite donor organ shortage, a large proportion of possible donor lungs are declined for transplantation. Criteria for accepting/declining lungs remain controversial because of the lack of adequate tools to aid in decision-making. We collected, air-inflated, and froze a large series of declined/unused donor lungs and subjected these lung specimens to CT examination. Affected target regions were scanned by using micro-CT. Lungs from 28 donors were collected. Two lungs were unused, six were declined for non–allograft-related reasons (collectively denominated nonallograft declines, n = 8), and 20 were declined because of allograft-related reasons. CT scanning demonstrated normal lung parenchyma in only four of eight nonallograft declines, while relatively normal parenchyma was found in 12 of 20 allograft-related declines. CT and micro-CT examinations confirmed the reason for decline in most lungs and revealed unexpected (unknown from clinical files or physical inspection) CT abnormalities in other lungs. CT-based measurements showed a higher mass and density in the lungs with CT alterations compared with lungs without CT abnormalities. CT could aid in the decision-making to accept or decline donor lungs which could lead to an increase in the quantity and quality of lung allografts.
  • Outcomes of Pediatric Kidney Transplantation in Recipients of a Previous Non-Renal Solid Organ Transplant
    Children who receive a non-renal solid organ transplant may develop secondary renal failure requiring kidney transplantation. We investigated outcomes of 165 pediatric kidney transplant recipients who previously received a heart, lung, or liver transplant using data from 1988 to 2012 reported to the United Network for Organ Sharing. Patient and allograft survival were compared with 330 matched primary kidney transplant (PKT) recipients. Kidney transplantation after solid organ transplant (KASOT) recipients experienced similar allograft survival: 5- and 10-year graft survival was 78% and 60% in KASOT recipients, compared to 80% and 61% in PKT recipients (p = 0.69). However, KASOT recipients demonstrated worse 10-year patient survival (75% KASOT vs. 97% PKT, p < 0.001). Competing risks analysis indicated that KASOT recipients more often experienced graft loss due to patient death (p < 0.001), whereas allograft failure per se was more common in PKT recipients (p = 0.01). To study more recent outcomes, kidney transplants performed from 2006 to 2012 were separately investigated. Since 2006, KASOT and PKT recipients had similar 5-year graft survival (82% KASOT vs. 83% PKT, p = 0.48), although 5-year patient survival of KASOT recipients remained inferior (90% KASOT vs. 98% PKT, p < 0.001). We conclude that despite decreased patient survival, kidney allograft outcomes in pediatric KASOT recipients are comparable to those of PKT recipients.
  • Improved Fetal Hemoglobin With mTOR Inhibitor–Based Immunosuppression in a Kidney Transplant Recipient With Sickle Cell Disease
    Fetal hemoglobin induction is a key point in the management of sickle cell disease (SCD). We report the case of a kidney transplant recipient with SCD who was treated with everolimus, a mammalian target of rapamycin inhibitor. At 10 months after initiating therapy, the patient's fetal hemoglobin level was dramatically increased (from 4.8% to 15%) and there was excellent tolerance to treatment.
  • Improving the Outcomes of Organs Obtained From Controlled Donation After Circulatory Death Donors Using Abdominal Normothermic Regional Perfusion
    The use of donation after circulatory death (DCD) has increased significantly during the past decade. However, warm ischemia results in a greater risk for transplantation. Indeed, controlled DCD (cDCD) was associated with inferior outcomes compared with donation after brain death. The use of abdominal normothermic regional perfusion (nRP) to restore blood flow before organ recovery in cDCD has been proposed as better than rapid recovery to reverse the effect of ischemia and improve recipients’ outcome. Here, the first Spanish series using abdominal nRP as an in situ conditioning method is reported. A specific methodology to avoid restoring circulation to the brain after death determination is described. Twenty-seven cDCD donors underwent abdominal nRP during at least 60 min. Thirty-seven kidneys, 11 livers, six bilateral lungs, and one pancreas were transplanted. The 1-year death-censored kidney survival was 91%, and delayed graft function rate was 27%. The 1-year liver survival rate was 90.1% with no cases of ischemic cholangiopathy. Transplanted lungs and pancreas exhibited primary function. The use of nRP may represent an advance to increase the number and quality of grafts in cDCD. Poor results in cDCD livers could be reversed with nRP. Concerns about restoring brain circulation after death are easily solved.
  • American Journal of Transplantation: Volume 17, Number 6, June 2017
    On the cover this month: Transplantation has long been known for its innovation in multidisciplinary care and long-term follow-up. This care is highly detailed and resource-intensive. In this month's AJT, Schmid et al (page 1594) report on a randomized controlled trial in living donor renal transplant recipients testing the effectiveness of telemedicine to facilitate outpatient case management. They demonstrate that it leads to a reduction in healthcare utilization, reduced healthcare costs, lower nonadherence, and better disease-specific quality of life. As the number of patients surviving with transplants continues to grow, innovations like these will be important in continuing high-quality, lifelong, multidisciplinary care. Cover design by Lauren Halligan, Duke University Department of Surgery.
  • Transplantation in Africa
    This issue of “The AJT Report” looks at the state of transplantation surgery in Africa, and the future of the specialty in the region. We also review the growing crisis of end-stage kidney disease in sub-Saharan countries and what healthcare authorities have done to address the problem.
  • Timing Is Everything
    Druzd and colleagues show that internal clocks govern entry and egress of lymphocytes within lymph nodes, imparting a time-dependent impact to the magnitude of an immune response.
  • Metrics and Data Analysis in Transplantation: Quality Improvement via Transparency
    Refinement of transplant analytics should reflect changes in clinical practice and allow meaningful comparisons between programs that could improve transplant outcomes. See the review from Kotton et al on page 1439.
  • The Effects of Center Volume on Mortality in Pediatric Heart Transplantation—The Rest of the Story
    In pediatric heart transplantation, waitlist mortality is affected by center volume more than posttransplant mortality, and it may be an important additional quality marker in the assessment of a center's performance. See Rana et al's article on page 1515.
  • Transplant Infectious Diseases: A Review of the Scientific Registry of Transplant Recipients Published Data
    The Scientific Registry of Transplant Recipients (SRTR) serves to collect data on organ transplants performed in the United States. Although the infectious diseases data are limited and include mostly pretransplant serologies and other nonspecific infection-related outcomes, this multicenter data collection allows for insightful national data and the ability to monitor trends over time. We reviewed the published concise reports for each organ type in SRTR reports containing data from 2005 to 2014, and summarized our findings with respect to cytomegalovirus (CMV), Epstein-Barr virus, posttransplant lymphoproliferative disorder (PTLD), hepatitis B virus (HBV), hepatitis C virus (HCV), HIV, general infection, and prophylaxis. Our review highlights a few developments. While rates of donor–recipient CMV serology combinations remain fairly constant over time, there are generally more seronegative donors and recipients among living donor transplants. There has been a reduction in PTLD for pediatric transplant recipients. There has also been a slight reduction in anti-HBV core antibody–positive donor organs and stable reporting of HCV-positive donor organs and HIV-positive recipients.
  • How Spain Reached 40 Deceased Organ Donors per Million Population
    With 40 donors and more than 100 transplant procedures per million population in 2015, Spain holds a privileged position worldwide in providing transplant services to its patient population. The Spanish success derives from a specific organizational approach to ensure the systematic identification of opportunities for organ donation and their transition to actual donation and to promote public support for the donation of organs after death. The Spanish results are to be highlighted in the context of the dramatic decline in the incidence of brain death and the changes in end-of-life care practices in the country since the beginning of the century. This prompted the system to conceive the 40 donors per million population plan, with three specific objectives: (i) promoting the identification and early referral of possible organ donors from outside of the intensive care unit to consider elective non-therapeutic intensive care and incorporate the option of organ donation into end-of-life care; (ii) facilitating the use of organs from expanded criteria and non–standard risk donors; and (iii) developing the framework for the practice of donation after circulatory death. This article describes the actions undertaken and their impact on donation and transplantation activities.
  • The Road to HLA Antibody Evaluation: Do Not Rely on MFI
    Technological advances in HLA laboratory testing undoubtedly improved the sensitivity and specificity of HLA antibody assessment but not without introducing a set of challenges regarding data interpretation. In particular, the introduction of solid-phase single-antigen bead (SAB) antibody assessment brought the belief that mean fluorescence intensity (MFI) was a quantifiable value. As such, MFI levels heavily influenced HLA antibody reporting, monitoring, and clinical practice. However, given that SAB testing was neither intended for nor approved to be quantifiable, is the use of MFI in current clinical and laboratory practice valid? What, if anything, does this numerical value actually reveal about the pathogenic potential of the antibody? What are the pitfalls and caveats associated with reporting MFI? Herein, we travel the road to HLA antibody assessment and explore the reliability of MFI values to make clinical decisions.
  • A Soluble Form of P Selectin Glycoprotein Ligand 1 Requires Signaling by Nuclear Factor Erythroid 2–Related Factor 2 to Protect Liver Transplant Endothelial Cells Against Ischemia–Reperfusion Injury
    Liver endothelial cell (LEC) damage is essential in the pathogenesis of ischemia–reperfusion injury (IRI) in transplant recipients. We analyzed the mechanism of LEC resistance against IRI by using a novel recombinant soluble form of P selectin glycoprotein ligand 1, tandem P selectin glycoprotein ligand immunoglobulin (TSGL-Ig), in a mouse model of hepatic cold preservation (4°C in University of Wisconsin solution for 20 h) and syngeneic orthotopic liver transplantation (OLT). Unlike controls, TSGL-Ig protected orthotopic liver transplants against ischemia–reperfusion (IR) stress, shown by depressed serum alanine aminotransferase levels, well-preserved hepatic architecture, and improved survival (42% vs. 92%). TSGL-Ig suppressed neutrophil/macrophage sequestration and proinflammatory cytokine/chemokine programs in OLT. Treatment with TSGL-Ig mitigated LEC activation (P and E selectin, VCAM-1 and intercellular adhesion molecule 1 expression). In parallel in vitro studies, TSGL-Ig diminished cellular damage in H2O2-stressed LEC cultures (lactic acid dehydrogenase and alanine aminotransferase levels). Increased thioredoxin, glutamate-cysteine ligase, NAD(P)H quinone dehydrogenase 1, and hypoxia-inducible factor 1α expression, along with transcription factor nuclear factor erythroid 2–related factor 2 (Nrf2), implied that TSGL-Ig exerts antioxidant functions in IR-stressed OLT and H2O2-stressed LECs. Indeed, Nrf2-deficient livers suffered fulminant IRI compared with WT despite concomitant TSGL-Ig therapy. Thus, TSGL-Ig is not only acting as a competitive antagonist blocking leukocyte migration into IR-stressed liver, but it may also act directly as an agonist stimulating Nrf2-mediated cytoprotection in LECs. This study supports the role of P selectin signaling in hepatic homeostasis in OLT, with broad implications for tissue damage conditions.
  • Renal Allograft Survival in Nonhuman Primates Infused With Donor Antigen-Pulsed Autologous Regulatory Dendritic Cells
    Systemic administration of autologous regulatory dendritic cells (DCreg; unpulsed or pulsed with donor antigen [Ag]), prolongs allograft survival and promotes transplant tolerance in rodents. Here, we demonstrate that nonhuman primate (NHP) monocyte-derived DCreg preloaded with cell membrane vesicles from allogeneic peripheral blood mononuclear cells induce T cell hyporesponsiveness to donor alloantigen (alloAg) in vitro. These donor alloAg-pulsed autologous DCreg (1.4–3.6 × 106/kg) were administered intravenously, 1 day before MHC-mismatched renal transplantation to rhesus monkeys treated with costimulation blockade (cytotoxic T lymphocyte Ag 4 immunoglobulin [CTLA4] Ig) and tapered rapamycin. Prolongation of graft median survival time from 39.5 days (no DCreg infusion; n = 6 historical controls) and 29 days with control unpulsed DCreg (n = 2), to 56 days with donor Ag-pulsed DCreg (n = 5) was associated with evidence of modulated host CD4+ and CD8+ T cell responses to donor Ag and attenuation of systemic IL-17 production. Circulating anti-donor antibody (Ab) was not detected until CTLA4 Ig withdrawal. One monkey treated with donor Ag-pulsed DCreg rejected its graft in association with progressively elevated anti-donor Ab, 525 days posttransplant (160 days after withdrawal of immunosuppression). These findings indicate a modest but not statistically significant beneficial effect of donor Ag-pulsed autologous DCreg infusion on NHP graft survival when administered with a minimal immunosuppressive drug regimen.
  • Renal Operational Tolerance Is Associated With a Defect of Blood Tfh Cells That Exhibit Impaired B Cell Help
    Renal operationally tolerant patients (TOL) display a defect in B cell differentiation, with a deficiency in plasma cells. Recently described, T follicular helper (Tfh) cells play a critical role in B cell differentiation. We analyzed blood Tfh subsets in TOL and transplanted patients with stable graft function under immunosuppression (STA). We observed a reduced proportion of blood activated and highly functional Tfh subsets in TOL, without affecting Tfh absolute numbers. Functionally, Tfh cells from TOL displayed a modified gene expression profile, failed to produce interleukin-21, and were unable to induce IgG production by naive B cells. This Tfh defect is linked to a low incidence of postgraft de novo donor-specific antibody (dnDSA) immunization, suggesting that the lack of Tfh cells in TOL may induce a protolerogenic environment with reduced risk of developing dnDSA. Finally, we showed that elevated Tfh in STA precedes the occurrence of dnDSA during an alloresponse. These data provide new insights into the mechanisms of antibody response in operational tolerance. Disrupted homeostasis and impaired Tfh function in TOL could lead to a reduced risk of developing dnDSA and suggest a predictive role of blood Tfh cells on the occurrence of dnDSA in transplant recipients.
  • T Cells Promote Bronchial Epithelial Cell Secretion of Matrix Metalloproteinase-9 via a C-C Chemokine Receptor Type 2 Pathway: Implications for Chronic Lung Allograft Dysfunction
    Chronic lung allograft dysfunction (CLAD) is the major limitation of long-term survival after lung transplantation. CLAD manifests as bronchiolitis obliterans syndrome (BOS) or restrictive allograft syndrome (RAS). Alloimmune reactions and epithelial-to-mesenchymal transition have been suggested in BOS. However, little is known regarding the role of allogenicity in epithelial cell differentiation. Primary human bronchial epithelial cells (BECs) were treated with activated T cells in the presence or absence of transforming growth factor (TGF)-β. The expression of epithelial and mesenchymal markers was investigated. The secretion of inflammatory cytokines and matrix metalloproteinase (MMP)-9 was measured in culture supernatants and in plasma from lung transplant recipients (LTRs): 49 stable, 29 with BOS, and 16 with RAS. We demonstrated that C-C motif chemokine 2 secreted by T cells supports TGF-β–induced MMP-9 production by BECs after binding to C-C chemokine receptor type 2. Longitudinal investigation in LTRs revealed a rise in plasma MMP-9 before CLAD onset. Multivariate analysis showed that plasma MMP-9 was independently associated with BOS (odds ratio [OR] = 6.19, p = 0.002) or RAS (OR = 3.9, p = 0.024) and predicted the occurrence of CLAD 12 months before the functional diagnosis. Thus, immune cells support airway remodeling through the production of MMP-9. Plasma MMP-9 is a potential predictive biomarker of CLAD.
  • Inferior Outcomes on the Waiting List in Low-Volume Pediatric Heart Transplant Centers
    Low case volume has been associated with poor outcomes in a wide spectrum of procedures. Our objective was to study the association of low case volume and worse outcomes in pediatric heart transplant centers, taking the novel approach of including waitlist outcomes in the analysis. We studied a cohort of 6482 candidates listed in the Organ Procurement and Transplantation Network for pediatric heart transplantation between 2002 and 2014; 4665 (72%) of the candidates underwent transplantation. Candidates were divided into groups according to the average annual transplantation volume of the listing center during the study period: more than 10, six to 10, three to five, or fewer than three transplantations. We used multivariate Cox regression analysis to identify independent risk factors for waitlist and posttransplantation mortality. Of the 6482 candidates, 24% were listed in low-volume centers (fewer than three annual transplantations). Of these listed candidates in low-volume centers, only 36% received a transplant versus 89% in high-volume centers (more than 10 annual transplantations) (p < 0.001). Listing at a low-volume center was the most significant risk factor for waitlist death (hazard ratio [HR] 4.5, 95% confidence interval [CI] 3.5–5.7 in multivariate Cox regression and HR 5.6, CI 4.4–7.3 in multivariate competing risk regression) and was significant for posttransplantation death (HR 1.27, 95% CI 1.0–1.6 in multivariate Cox regression). During the study period, one-fourth of pediatric transplant candidates were listed in low-volume transplant centers. These children had a limited transplantation rate and a much greater risk of dying while on the waitlist.
  • The Influence of Race and Common Genetic Variations on Outcomes After Pediatric Heart Transplantation
    Significant racial disparity remains in the incidence of unfavorable outcomes following heart transplantation. We sought to determine which pediatric posttransplantation outcomes differ by race and whether these can be explained by recipient demographic, clinical, and genetic attributes. Data were collected for 80 black and 450 nonblack pediatric recipients transplanted at 1 of 6 centers between 1993 and 2008. Genotyping was performed for 20 candidate genes. Average follow-up was 6.25 years. Unadjusted 5-year rates for death (p = 0.001), graft loss (p = 0.015), acute rejection with severe hemodynamic compromise (p = 0.001), late rejection (p = 0.005), and late rejection with hemodynamic compromise (p = 0.004) were significantly higher among blacks compared with nonblacks. Black recipients were more likely to be older at the time of transplantation (p < 0.001), suffer from cardiomyopathy (p = 0.004), and have public insurance (p < 0.001), and were less likely to undergo induction therapy (p = 0.0039). In multivariate regression models adjusting for age, sex, cardiac diagnosis, insurance status, and genetic variations, black race remained a significant risk factor for all the above outcomes. These clinical and genetic variables explained only 8–19% of the excess risk observed for black recipients. We have confirmed racial differences in survival, graft loss, and several rejection outcomes following heart transplantation in children, which could not be fully explained by differences in recipient attributes.
  • Effect of Replacing Race With Apolipoprotein L1 Genotype in Calculation of Kidney Donor Risk Index
    Renal allografts from deceased African American donors with two apolipoprotein L1 gene (APOL1) renal-risk variants fail sooner than kidneys from donors with fewer variants. The Kidney Donor Risk Index (KDRI) was developed to evaluate organ offers by predicting allograft longevity and includes African American race as a risk factor. Substituting APOL1 genotype for race may refine the KDRI. For 622 deceased African American kidney donors, we applied a 10-fold cross-validation approach to estimate contribution of APOL1 variants to a revised KDRI. Cross-validation was repeated 10 000 times to generate distribution of effect size associated with APOL1 genotype. Average effect size was used to derive the revised KDRI weighting. Mean current-KDRI score for all donors was 1.4930 versus mean revised-KDRI score 1.2518 for 529 donors with no or one variant and 1.8527 for 93 donors with two variants. Original and revised KDRIs had comparable survival prediction errors after transplantation, but the spread in Kidney Donor Profile Index based on presence or absence of two APOL1 variants was 37 percentage points. Replacing donor race with APOL1 genotype in KDRI better defines risk associated with kidneys transplanted from deceased African American donors, substantially improves KDRI score for 85–90% of kidneys offered, and enhances the link between donor quality and recipient need.
  • Relationship Among Viremia/Viral Infection, Alloimmunity, and Nutritional Parameters in the First Year After Pediatric Kidney Transplantation
    The Immune Development in Pediatric Transplantation (IMPACT) study was conducted to evaluate relationships among alloimmunity, protective immunity, immune development, physical parameters, and clinical outcome in children undergoing kidney transplantation. We prospectively evaluated biopsy-proven acute rejection (BPAR), de novo donor-specific antibody (dnDSA) formation, viremia, viral infection, T cell immunophenotyping, and body mass index (BMI)/weight Z scores in the first year posttransplantation in 106 pediatric kidney transplant recipients. Outcomes were excellent with no deaths and 98% graft survival. Rejection and dnDSAs occurred in 24% and 22%, respectively. Pretransplant cytomegalovirus (CMV) and Epstein–Barr virus (EBV) serologies and subsequent viremia were unrelated to BPAR or dnDSA. Viremia occurred in 73% of children (EBV, 34%; CMV, 23%; BMK viremia, 23%; and JC virus, 21%). Memory lymphocyte phenotype at baseline was not predictive of alloimmune complications. Patients who developed viral infection had lower weight (−2.1) (p = 0.028) and BMI (−1.2) (p = 0.048) Z scores at transplantation. The weight difference persisted to 12 months compared with patients without infection (p = 0.038). These data indicate that there is a high prevalence of viral disease after pediatric kidney transplantation, and underweight status at transplantation appears to be a risk factor for subsequent viral infection. The occurrence of viremia/viral infection is not associated with alloimmune events.
  • Reactivation of Latent HPV Infections After Renal Transplantation
    Female renal transplant recipients (RTRs) have an increased risk for developing human papillomavirus (HPV)–related (pre)malignant lesions of the genital tract. This study aims to assess the genital prevalence of HPV before and after renal transplantation (RT). In female patients who were counseled for RT at the Radboud University Medical Center Nijmegen, the Netherlands, gynecological examination was performed at first visit, and 1 and 2 years later. HPV self-sampling and questionnaires on sexual behavior were performed every 3 months. In 65 patients who underwent RT, the high-risk human papillomavirus (hrHPV) prevalence as assessed with the highly sensitive SPF10 -LiPA25 test increased significantly from 19% before to 31% after RT (p = 0.045). Based upon the clinically validated Cobas 4800 HPV test, the hrHPV prevalence increased from 10% before to 14% after RT (p = 0.31). During follow-up, no changes in sexual behavior were reported. Thirty-three patients who did not undergo RT showed a hrHPV prevalence of 21% at study entry and of 27% after 12 months with the sensitive test, and a stable prevalence of 16% with the clinically validated test. The results of this study indicate that activation of latent HPV infections may contribute to the increased risk of HPV-related (pre)malignant lesions in female RTRs.
  • The Value of Protocol Biopsies to Identify Patients With De Novo Donor-Specific Antibody at High Risk for Allograft Loss
    De novo donor-specific antibody (dnDSA) is associated with antibody-mediated rejection (AMR) and allograft loss, yet the allograft histology associated with dnDSA remains unclear. The aim of this study was to examine the allograft histology associated with dnDSA in patients with serial surveillance biopsies. We retrospectively studied adult conventional solitary kidney transplant recipients from October 2007 to May 2014. The definition of dnDSA was new donor-specific antibody (DSA) with mean fluorescence intensity (MFI) >1000. The incidence of dnDSA was 7.0% (54 of 771) over mean follow-up of 4.2 ± 1.9 years. Patients with dnDSA had reduced death-censored allograft survival (87.0% vs. 97.0% no dnDSA, p < 0.01). Moreover, 94% of patients received a biopsy after dnDSA (mean of three biopsies per patient). AMR was present in 25.0% and 52.9% of patients at dnDSA detection and at 1 year, respectively. Patients with both class I and II dnDSA had the highest rate of allograft loss. The higher the sum MFI at dnDSA detection, the higher the incidence of AMR. In conclusion, patients with dnDSA without AMR at time of detection may benefit from a follow-up biopsy within 1 year because AMR can be missed initially. In addition, the dnDSA class and sum MFI at baseline appear to be prognostic. The higher the sum MFI of dnDSA at baseline, the higher the incidence of AMR.
 

 

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