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BACKGROUND: After lung transplantation, both frailty and chronic lung allograft dysfunction (CLAD) commonly develop, and when they do, are associated with poorer outcomes. Given their potential shared mechanisms, we sought to explore the temporal relationship between frailty and CLAD onset. METHODS: In a single center, we prospectively measured frailty by the short physical performance battery (SPPB) repeatedly after transplant. Because of the nature of the relationship between frailty and CLAD is unknown, we tested the association between frailty, modeled as a time-dependent predictor, and CLAD development as well as CLAD development, modeled as a time-dependent predictor, and frailty development. To do so, we used Cox proportional cause-specific hazards and conditional logistic regression models adjusted for age, sex, race, diagnosis, cytomegalovirus serostatus, posttransplant body mass index, and acute cellular rejection episodes as time-dependent covariates. We tested SPPB frailty as a binary (≤9 points) and continuous predictor (12-point scale); as an outcome, we defined frailty as SPPB ≤9. RESULTS: The 231 participants were a mean age of 55.7 y (SD 12.1). After adjusting for covariates, the development of frailty within 3 y after lung transplant was associated with cause-specific CLAD risk (adjusted cause-specific hazard ratio: 1.76; 95% confidence interval [CI], 1.05-2.92 when defining frailty as SPPB ≤9 and adjusted cause-specific hazard ratio: 1.10, 95% CI, 1.03-1.18 per 1-point worsening in SPPB). CLAD onset did not appear to be a risk factor for subsequent frailty (odds ratio, 4.0; 95% CI, 0.4-197.0). CONCLUSIONS: Studying the mechanisms underlying frailty and CLAD could provide new insights into the pathobiology of both and potential targets for intervention.

BackgroundChronic lung allograft dysfunction (CLAD) phenotype determines prognosis and may have therapeutic implications. Despite the clarity achieved by recent consensus statement definitions, their reliance on radiologic interpretation introduces subjectivity. The Center for Computer Vision and Imaging Biomarkers at the University of California, Los Angeles (UCLA) has established protocols for chest high-resolution computed tomography (HRCT)-based computer-aided quantification of both interstitial disease and air-trapping. We applied quantitative image analysis (QIA) at CLAD onset to demonstrate radiographic phenotypes with clinical implications.MethodsWe studied 47 first bilateral lung transplant recipients at UCLA with chest HRCT performed within 90 d of CLAD onset and 47 no-CLAD control HRCTs. QIA determined the proportion of lung volume affected by interstitial disease and air-trapping in total lung capacity and residual volume images, respectively. We compared QIA scores between no-CLAD and CLAD, and between phenotypes. We also assigned radiographic phenotypes based solely on QIA, and compared their survival outcomes.ResultsCLAD onset HRCTs had more lung affected by the interstitial disease (P = 0.003) than no-CLAD controls. Bronchiolitis obliterans syndrome (BOS) cases had lower scores for interstitial disease as compared with probable restrictive allograft syndrome (RAS) (P < 0.0001) and mixed CLAD (P = 0.02) phenotypes. BOS cases had more air-trapping than probable RAS (P < 0.0001). Among phenotypes assigned by QIA, the relative risk of death was greatest for mixed (relative risk [RR] 11.81), followed by RAS (RR 6.27) and BOS (RR 3.15).ConclusionsChest HRCT QIA at CLAD onset appears promising as a method for precise determination of CLAD phenotypes with survival implications.

BackgroundKidney transplant patients are at high risk for coronavirus disease 2019 (COVID-19)-related mortality. However, limited data are available on longer-term clinical, functional, and mental health outcomes in patients who survive COVID-19.MethodsWe analyzed data from adult kidney transplant patients in the European Renal Association COVID-19 Database who presented with COVID-19 between February 1, 2020, and January 31, 2021.ResultsWe included 912 patients with a mean age of 56.7 (±13.7) y. 26.4% were not hospitalized, 57.5% were hospitalized without need for intensive care unit (ICU) admission, and 16.1% were hospitalized and admitted to the ICU. At 3 mo follow-up survival was 82.3% overall, and 98.8%, 84.2%, and 49.0%, respectively, in each group. At 3 mo follow-up biopsy-proven acute rejection, need for renal replacement therapy, and graft failure occurred in the overall group in 0.8%, 2.6%, and 1.8% respectively, and in 2.1%, 10.6%, and 10.6% of ICU-admitted patients, respectively. Of the surviving patients, 83.3% and 94.4% reached their pre-COVID-19 physician-reported functional and mental health status, respectively, within 3 mo. Of patients who had not yet reached their prior functional and mental health status, their treating physicians expected that 79.6% and 80.0%, respectively, still would do so within the coming year. ICU admission was independently associated with a low likelihood to reach prior functional and mental health status.ConclusionsIn kidney transplant recipients alive at 3-mo follow-up, clinical, physician-reported functional, and mental health recovery was good for both nonhospitalized and hospitalized patients. Recovery was, however, less favorable for patients who had been admitted to the ICU.

BackgroundDeceased donor and recipient predictors of posttransplant steatosis/steatohepatitis and fibrosis are not well known. Our aim was to evaluate the prevalence and assess donor and recipient predictors of steatosis, steatohepatitis, and fibrosis in liver transplantation recipients.MethodsUsing the immune tolerance network A-WISH multicenter study (NCT00135694), donor and recipient demographic and clinical features were collected. Liver biopsies were taken from the donor liver at transplant, and from recipients per protocol and for-cause (ie, abnormal transaminases and to rule out rejection) and were interpreted by a central pathologist.ResultsOne hundred eighty-three paired donor/recipients liver biopsies at the time of transplant and posttransplant follow-up (median time 582 d; average time to last biopsies was 704 d [SD ± 402 d]) were analyzed. Donor steatosis did not influence recipient steatosis or fibrosis. Ten of 183 recipients had steatohepatitis on the last biopsy. Recipient body mass index at the time of liver biopsy was the most influential factor associated with posttransplant steatosis. Both donor and recipient metabolic syndrome features were not associated with graft steatosis. Untreated hepatitis C viral (HCV) infection was the most influential factor associated with the development of allograft fibrosis.ConclusionsIn a large experience evaluating paired donor and recipient characteristics, recipient body mass index at the time of liver biopsy was most significantly associated with posttransplant steatosis. Untreated HCV etiology influenced graft fibrosis. Thus relative to untreated HCV, hepatic fibrosis in those with steatosis/steatohepatitis is less common though long-term follow-up is needed to determine the course of posttransplant fibrosis. Emphasis on recipient weight control is essential.

BackgroundWomen with chronic liver disease have lower rates of hepatocellular carcinoma (HCC) as compared to men; it is unknown if there are sex-based differences in HCC recurrence postliver transplant.MethodsWe conducted an analysis of patients who underwent liver transplant for HCC in the United Network for Organ Sharing/Organ Procurement and Transplantation Network from January 1, 2012 through December 31, 2017.ResultsA total of 12 711 patients underwent liver transplant for HCC: 2909 (23%) women and 9802 (73%) men. Women had significantly lower rates of postliver transplant HCC recurrence than men (4.0% versus 5.4%, P = 0.002). A cox-regression analysis for postliver transplant HCC recurrence highlighted that even after accounting for etiology of cirrhosis, alpha-fetoprotein at liver transplant, tumor diameter, tumor pathology, and vascular invasion, female sex was associated with a 25% lower risk of postliver transplant HCC recurrence (95% confidence interval: 0.57-0.99). There were no interactions between female sex and the following variables: age, type of locoregional therapy, alpha-fetoprotein, donor sex, body mass index, or nonalcoholic steatohepatitis etiology (P > 0.05 for each).ConclusionsThis study demonstrates an independent effect of sex on risk for HCC recurrence postliver transplant. Our data highlight an opportunity to better understand HCC tumor biology by investigating the drivers of this sex-based difference in HCC recurrence.

BackgroundA major discrepancy between clinical and most experimental settings of liver ischemia-reperfusion injury (IRI) is the allogenicity.MethodsIn the current study, we first established a murine model of allogeneic orthotopic liver transplantation with extended cold ischemia time (18 h). Roles of CD4 T cells in the pathogenesis of IRI in liver allografts were determined using a depleting anti-CD4 antibody. The clinical relevance of CD4 as a marker of liver IRI was analyzed retrospectively in 55 liver transplant patients.ResultsCD4 depletion in both donors and recipients resulted in the most effective protection of liver allografts from IRI, as measured by serum transaminase levels and liver histology. CD4 depletion inhibited IR-induced intragraft neutrophil/macrophage infiltration and proinflammatory gene expressions. Quantitative reverse-transcriptase polymerase chain reaction analysis of human liver biopsies (2 h postreperfusion) revealed that posttransplant, rather than pretransplant, CD4 transcript levels correlated positively with proinflammatory gene expression profile. When we divided patients into subgroups according to intragraft CD4 levels, the high CD4 cohort developed a more severe hepatocellular damage than that with low CD4 levels.ConclusionsCD4 T cells play a key pathogenic role in IRI of allogeneic liver transplants, and intragraft CD4 levels in the early postreperfusion phase may serve as a potential biomarker and therapeutic target to ameliorate liver IRI and improve orthotopic liver transplantation outcomes.

BackgroundT lymphocyte-mediated acute rejection is a significant complication following solid organ transplantation. Standard methods of monitoring for acute rejection rely on assessing histological tissue damage but do not define the immunopathogenesis. Additionally, current therapies for rejection broadly blunt cellular immunity, creating a high risk for opportunistic infections. There is, therefore, a need to better understand the process of acute cellular rejection to help develop improved prognostic tests and narrowly targeted therapies.MethodsThrough next-generation sequencing, we characterized and compared the clonal T-cell receptor (TCR) repertoires of graft-infiltrating lymphocytes (GILs) and blood-derived lymphocytes from a hand transplant recipient over 420 days following transplantation. We also tracked the TCR clonal persistence and V beta (BV) gene usage, evaluating overlap between these 2 compartments.ResultsTCR repertoires of blood and GIL populations remained distinct throughout the sampling period, and differential BV usage was consistently seen between these compartments. GIL TCR clones persisted over time and were seen in only limited frequency in the blood T-lymphocyte populations.ConclusionsWe demonstrate that blood monitoring of TCR clones does not reveal the pathogenic process of acute cellular rejection in transplanted tissue. GILs show clonal persistence with biased BV usage, suggesting that tissue TCR clonal monitoring could be useful, although a deeper understanding is necessary to prognosticate rejection based on TCR clonal repertoires. Finally, the distinct TCR BV usage bias in GILs raises the possibility for prevention and therapy of acute cellular rejection based on targeting of specific TCR clones.

BackgroundThe use of living donor liver transplantation (LDLT) for primary liver transplantation (LT) may quell concerns about allocating deceased donor organs if the need for retransplantation (re-LT) arises because the primary LT did not draw from the limited organ pool. However, outcomes of re-LT after LDLT are poorly studied. The purpose of this study was to analyze the Adult to Adult Living Donor Liver Transplantation Study (A2ALL) data to report outcomes of re-LT after LDLT, with a focus on long-term survival after re-LT.MethodsA retrospective review of A2ALL data collected between 1998 and 2014 was performed. Patients were excluded if they received a deceased donor LT. Demographic data, postoperative outcomes and complications, graft and patient survival, and predictors of re-LT and patient survival were assessed.ResultsOf the 1065 patients who underwent LDLT during the study time period, 110 recipients (10.3%) required re-LT. In multivariable analyses, hepatitis C virus, longer length of stay at LDLT, hepatic artery thrombosis, biliary stricture, infection, and disease recurrence were associated with an increased risk of re-LT. Patient survival among re-LT patients was significantly inferior to those who underwent primary transplant only at 1 (86% versus 92%), 5 (64% versus 82%), and 10 years (44% versus 68%).ConclusionsApproximately 10% of A2ALL patients who underwent primary LDLT required re-LT. Compared with patients who underwent primary LT, survival among re-LT recipients was worse at 1, 5, and 10 years after LT, and re-LT was associated with a significantly increased risk of death in multivariable modeling (hazard ratios, 2.29; P

BackgroundWith the implementation of the "Safety Net," we aimed to determine the impact of simultaneous liver-kidney transplantation (SLKT), as compared to kidney transplant after liver transplant (KALT), on kidney allograft failure (KF).MethodsAn analysis of the UNOS database for all adult patients who received either an SLKT or KALT from 2002 to 2017. The outcomes were 90-day KF and 1-year KF (as reported to UNOS, at 90- and 365-day postkidney transplant, respectively). We compared the following groups of patients: SLKT

BackgroundShare 35 was a policy implemented in 2013 to increase regional sharing of deceased donor livers to patients with model for end-stage liver disease ≥ 35 to decrease waitlist mortality for the sickest patients awaiting liver transplantation (LT). The purpose of this study was to determine whether live donor liver transplantation (LDLT) volume was impacted by the shift in allocation of deceased donor livers to patients with higher model for end-stage liver disease scores.MethodsUsing Network for Organ Sharing/Organ Procurement and Transplantation Network Standard Transplant Analysis and Research files, we identified all adults who received a primary LT between October 1, 2008, and March 31, 2018. LT from October 1, 2008, through June 30, 2013, was designated as the pre-Share 35 era and July 1, 2013, through March 31, 2018, as the post-Share 35 era. Primary outcomes included transplant volumes, graft survival, and patient survival in both eras.ResultsIn total, 48 779 primary adult single-organ LT occurred during the study period (22 255 pre-Share 35, 26 524 post). LDLT increased significantly (6.8% post versus 5.7% pre, P

BackgroundCritically ill cirrhotic patients are increasingly transplanted, but there is no consensus about futile liver transplantation (LT). Therefore, the decision to delay or deny LT is often extensively debated. These debates arise from different opinions of futility among transplant team members. This study aims to achieve a multinational and multidisciplinary consensus on the definition of futility in LT and to develop well-articulated criteria for not proceeding with LT due to futility.MethodsThirty-five international experts from anesthesiology/intensive care, hepatology, and transplant surgery were surveyed using the Delphi method. More than 70% of similar answers to a question were necessary to define agreement.ResultsThe panel recommended patient and graft survival at 1 year after LT to define futility. Severe frailty and persistent fever or 1 μg/kg per minute and a serum lactate level >9 mmol/L.ConclusionsOur expert panel provides a consensus on the definition of futile LT and on specific criteria for postponing or denying LT. A framework that may facilitate the decision if a patient is too sick for transplant is presented.

BackgroundNeighborhood socioeconomic deprivation is associated with adverse health outcomes. We sought to determine if neighborhood socioeconomic deprivation was associated with adherence to immunosuppressive medications after liver transplantation.MethodsWe conducted a secondary analysis of a multicenter, prospective cohort of children enrolled in the medication adherence in children who had a liver transplant study (enrollment 2010-2013). Participants (N = 271) received a liver transplant ≥1 year before enrollment and were subsequently treated with tacrolimus. The primary exposure, connected to geocoded participant home addresses, was a neighborhood socioeconomic deprivation index (range 0-1, higher indicates more deprivation). The primary outcome was the medication level variability index (MLVI), a surrogate measure of adherence to immunosuppression in pediatric liver transplant recipients. Higher MLVI indicates worse adherence behavior; values ≥2.5 are predictive of late allograft rejection.ResultsThere was a 5% increase in MLVI for each 0.1 increase in deprivation index (95% confidence interval, -1% to 11%; P = 0.08). Roughly 24% of participants from the most deprived quartile had an MLVI ≥2.5 compared with 12% in the remaining 3 quartiles (P = 0.018). Black children were more likely to have high MLVI even after adjusting for deprivation (adjusted odds ratio 4.0 95% confidence interval, 1.7-10.6).ConclusionsThis is the first study to evaluate associations between neighborhood socioeconomic deprivation and an objective surrogate measure of medication adherence in children posttransplant. These findings suggest that neighborhood context may be an important consideration when assessing adherence. Differential rates of medication adherence may partly explain links between neighborhood factors and adverse health outcomes following pediatric liver transplantation.

BackgroundThe novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) disease has transformed innumerable aspects of medical practice, particularly in the field of transplantation.Main bodyHere we describe a single-center approach to creating a generalizable, comprehensive, and graduated set of recommendations to respond in stepwise fashion to the challenges posed by these conditions, and the underlying principles guiding such decisions.ConclusionsCreation of a stepwise plan will allow transplant centers to respond in a dynamic fashion to the ongoing challenges posed by the COVID-19 pandemic.

BackgroundNon-Hispanic black (NHB) and Hispanic patients have lower access to kidney transplantation compared to non-Hispanic whites (NHWs). We examined whether differences in the prevalence of comorbidities that affect eligibility for transplant contribute to disparities in receipt of transplantation.MethodsWe performed a retrospective study of 986 019 adults who started dialysis between 2005 and 2014, according to the United States Renal Data System. We compared prevalence of comorbidities that could influence transplant eligibility by race/ethnicity. We examined time to first transplant by race/ethnicity in this overall cohort and in a very healthy sub-cohort without conditions that could be contraindications to transplantation.ResultsDuring 2.3 years of mean follow-up, 64 892 transplants occurred. NHBs and Hispanics had a lower prevalence of medical barriers to transplantation at the time of dialysis initiation than NHWs, including age >70 years (26% in NHB versus 47% in NHW) and malignancy (4% in Hispanics versus 10% in NHWs). Access to transplant was 65% lower (95% CI, 0.33-0.37) in NHBs and 43% lower (95% CI, 0.54-0.62) in Hispanics (versus NHWs) in the first year after end-stage renal disease, but by Year 4, access to transplantation was not statistically significantly different between Hispanics or NHBs (versus NHWs). In our very healthy cohort, racial and ethnic disparities in access to transplantation persisted up to Year 5 in NHBs and Year 4 in Hispanics after end-stage renal disease onset.ConclusionsDifferences in medical eligibility do not appear to explain racial/ethnic disparities in receipt of kidney transplantation and may mask the actual magnitude of the inequities that are present.

Risk scoring for patients with cirrhosis has evolved greatly over the past several decades. However, patients with low Model for End-Stage Liver Disease-Sodium scores still suffer from liver-related morbidity and mortality. Unfortunately, it is not clear which of these low Model for End-Stage Liver Disease-Sodium score patients would benefit from earlier consideration of liver transplantation. This article reviews the literature of risk prediction in patients with cirrhosis, identifies which patients may benefit from earlier interventions, such as transplantation, and proposes directions for future research.

BackgroundAlcoholic liver disease (ALD) accounts for 15%-30% of transplants performed in the United States and Europe; however, the data on living donor liver transplantation (LDLT) for ALD remain sparse. The purpose of this study was to examine the outcomes following LDLT for ALD using data from the adult-to-adult living donor liver transplantation (A2ALL) study, which represents the largest Western experience with adult-to-adult LDLT.MethodsA retrospective review of A2ALL data collected between 1998 and 2014 was performed. Patients were excluded if they received a deceased donor liver transplant. Demographic data, postoperative outcomes and complications, graft and patient survival, and predictors of graft and patient survival were assessed.ResultsOf the 1065 patients who underwent LDLT during the study time period, 168 (15.8%) were transplanted for a diagnosis of ALD. Comparing patients who underwent transplant for ALD with those who were transplanted for other etiologies of liver disease, there was no significant difference in graft survival at 1 (88% versus 84%), 5 (76% versus 74%), or 10 years following transplant (55% versus 61%, P = 0.29). Similarly, there was no difference in patient survival at 1 (94% versus 91%), 5 (83% versus 79%), or 10 years following transplant (61% versus 66%, P = 0.32).ConclusionsLDLT for ALD results in excellent 1-, 5-, and 10-year graft and patient survival. Patients with ALD and impaired renal function have a higher risk of graft loss and death. These findings support the notion that early LDLT for patients with ALD may help optimize outcomes.

BackgroundTransplant education in dialysis centers can increase access to kidney transplant; however, dialysis center transplant barriers are common, and limited research identifies the most effective transplant education approaches.MethodsWe surveyed transplant educators in 1694 US dialysis centers about their transplant knowledge, use of 12 education practices, and 8 identified education barriers. Transplant wait-listing rates were calculated using US Renal Data System data.ResultsFifty-two percent of educators orally recommended transplant to patients, 31% had in-center transplant discussions with patients, 17% distributed print educational resources, and 3% used intensive education approaches. Distribution of print education (incident rate ratio: 1.021.151.30) and using >1 intensive education practice (1.001.111.23) within dialysis centers were associated with increased wait-listing rates. Several dialysis center characteristics were associated with reduced odds of using education strategies leading to increased wait-listing. Centers with greater percentages of uninsured patients (odds ratio [OR]: 0.960.970.99), in rural locations (OR: 0.660.790.95), with for-profit ownership (OR: 0.640.770.91), and with more patients older than 65 years (OR: 0.050.110.23) had lower odds of recommending transplant, while centers with a higher patient-to-staff ratio were more likely to do so (OR: 1.011.031.04). Language barriers (OR: 0.480.640.86) and having competing work priorities (OR: 0.400.530.70) reduced the odds of distributing print education. Providers with greater transplant knowledge were more likely to use >1 intensive educational strategy (OR: 1.011.271.60) while providers who reported competing work priorities (OR: 0.510.660.84) and poor communication with transplant centers (OR: 0.580.760.98) were less likely to do so.ConclusionsEducators should prioritize transplant education strategies shown to be associated with increasing wait-listing rates.

BackgroundWe examined the association between sarcopenia and post-transplant mortality in acutely ill inpatients with cirrhosis who underwent urgent liver transplantation.MethodsIncluded were inpatients at 4 centers who were urgently listed as nonstatus 1 and transplanted from 2005 to 2017 with an abdominal computed tomography scan 48 cm/m experienced higher rates of death at 1 year (86% versus 95%) and 3 years (73% versus 95%) (Log-rank P = 0.01). In MELD-adjusted analysis, sarcopenia was strongly associated with post-transplant mortality (HR = 4.39, 95% CI 1.49-12.97). Among women, 35% died. Median SMI was similar in women who died versus survived (45 versus 44 cm/m). SMI was not associated with post-transplant mortality (HR = 1.02, 95% CI 0.96-1.09). Optimal search did not identify any SMI cutoff that predicted post-transplant mortality.ConclusionsAmong patients who underwent urgent inpatient evaluation and liver transplantation, we identified an SMI cutoff value of 48 cm/m to predict post-transplant mortality in men. Our data support the use of SMI as a tool to capture the impact of muscle depletion on post-transplant mortality in acutely ill men with cirrhosis undergoing urgent liver transplantation.

BACKGROUND: Identifying kidney allograft recipients who are predisposed to acute rejection (AR) could allow for optimization of clinical treatment to avoid rejection and prolong graft survival. It has been hypothesized that a part of this predisposition is caused by the inheritance of specific genetic variants. There are many publications reporting a statistically significant association between a genetic variant, usually in the form of a single-nucleotide polymorphism (SNP), and AR. However, there are additional publications reporting a lack of this association when a different cohort of recipients is analyzed for the same single-nucleotide polymorphism. METHODS: In this report, we attempted to validate 75 common genetic variants, which have been previously reported to be associated with AR, using a large kidney allograft recipient cohort of 2390 European Americans and 482 African Americans. RESULTS: Of those variants tested, only 1 variant, rs2910164, which alters the expression of the microRNA MIR146A, was found to exhibit a significant association within the African American cohort. Suggestive variants were found in the genes CTLA and TLR4. CONCLUSIONS: Our results show that most variants previously reported to be associated with AR were not validated in our cohort. This shows the importance of validation when reporting the associations with complex clinical outcomes such as AR. Additional work will need to be done to understand the role of MIR146A in the risk of AR in kidney allograft recipients.

BackgroundKidney transplant is the best treatment for most end-stage renal disease (ESRD) patients, but proportionally few ESRD patients receive kidney transplant. To make an informed choice about whether to pursue kidney transplant, patients must be knowledgeable of its risks and benefits. To reliably and validly measure ESRD patients' kidney transplant knowledge, rigorously tested measures are required. This article describes the development and psychometric testing of the Knowledge Assessment of Renal Transplantation (KART).MethodsWe administered 17 transplant knowledge items to a sample of 1294 ESRD patients. Item characteristics and scale scores were estimated using an Item Response Theory graded response model. Construct validity was tested by examining differences in scale scores between patients who had spent less than 1 and 1 hour or longer receiving various types of transplant education.ResultsItem Response Theory modeling suggested that 15 items should be retained for the KART. This scale had a marginal reliability of 0.75 and evidenced acceptable reliability (>0.70) across most of its range. Construct validity was supported by the KART's ability to distinguish patients who had spent less than 1 and 1 hour or longer receiving different types of kidney transplant education, including talking to doctors/medical staff (effect size [ES], 0.61; P < 0.001), reading brochures (ES, 0.45; P < 0.001), browsing the internet (ES, 0.56; P < 0.001), and watching videos (ES, 0.56; P < 0.001).ConclusionsThe final 15-item KART can be used to determine the kidney transplant knowledge levels of ESRD patients and plan appropriate interventions to ensure informed transplant decision making occurs.

BackgroundIn the United States, 1 in 10 infants and 1 in 20 older children die on the liver transplant waiting list. Increasing split liver transplantation could increase organ availability for these children, without decreasing transplants in adults.MethodsUsing United Network for Organ Sharing Standard Transplant Analysis and Research data, we identified livers transplanted 2010 to 2015 that could potentially have been used for split transplant, based on strict criteria. Livers not suitable for pediatric patients or allocated to high-risk recipients were excluded. Number and distribution of potentially "split-able" livers were compared to pediatric waitlist deaths in each region.ResultsOf 37 333 deceased donor livers transplanted, 6.3% met our strict criteria for utilization in split liver transplant. Only 3.8% of these were actually utilized for split liver transplantation. 96% were used for a single adult recipient. Of the 2253 transplanted as whole livers, 82% of their recipients were listed as willing to accept a segmental liver, and only 3% were listed as requiring a cold ischemia time less than 6 hours. Over the same 5 years, 299 children died on the waitlist. In every United Network for Organ Sharing region, there were more potentially "split-able" livers than pediatric waitlist deaths. Thirty-seven percent of pediatric waitlist deaths occurred at transplant centers that averaged 1 or less pediatric split liver transplantation annually during the study period.ConclusionsThis comparison, although not conclusive, suggests that we might be missing opportunities to reduce pediatric waitlist mortality without decreasing access for adults-using split liver transplant. Barriers are significant, but further work on strategies to increase split liver transplant is warranted.

BackgroundCytomegalovirus (CMV) infection is a risk factor for chronic lung allograft dysfunction (CLAD), which limits survival in lung allograft recipients. Natural killer (NK) cells that express the NKG2C receptor mediate CMV-specific immune responses. We hypothesized that NKG2C NK cells responding to CMV in the lung allograft would reduce CMV-related inflammation and would improve CLAD-free survival.MethodsWe prospectively followed 130 subjects who underwent lung transplantation from 2012 to 2016. Bronchoalveolar lavage (BAL) NK cells were immunophenotyped for NKG2C, maturation, and proliferation markers. CMV viral load, serologies, serial spirometry, and mortality were recorded from medical records. Natural killer cell subset association with CMV endpoints were made using generalized estimating equation-adjusted linear models. BAL NKG2C NK cell association with CLAD-free survival was assessed by Cox proportional hazards modeling.ResultsNKG2C NK cells were more mature and proliferative than NKG2C NK cells and represented a median of 7.8% of BAL NK cells. The NKG2C NK cell proportion increased prior to the first detection of viremia and was nearly tripled in subjects with high level viremia (>1000 copies/mL) compared with no detected viremia. Subjects with increased BAL NKG2C NK cells, relative to the median, had a significantly increased risk for CLAD or death (hazard ratio, 4.2; 95% confidence interval, 1.2-13.3).ConclusionsThe BAL NKG2C NK cell proportion may be a relevant biomarker for assessing risk of CMV viremia and quantifying potential CMV-related graft injury that can lead to CLAD or death.

BackgroundDonor-specific HLA antibodies (DSA) are associated with increased rates of rejection and of graft failure in cardiac transplantation. The goal of this study was to determine the association of preformed and posttransplant development of newly detected DSA (ndDSA) with antibody-mediated rejection (AMR) and characterize the clinical relevance of complement-activating DSA in heart allograft recipients.MethodsThe study included 128 adult and 48 pediatric heart transplant patients transplanted between 2010 and 2013. Routine posttransplant HLA antibody testing was performed by IgG single-antigen bead test. The C3d single-antigen bead assay was used to identify complement-activating antibodies. Rejection was diagnosed using International Society for Heart and Lung Transplantation criteria.ResultsIn this study, 22 patients were transplanted with preexisting DSA, and 43 patients developed ndDSA posttransplant. Pretransplant (P < 0.05) and posttransplant (P < 0.001) ndDSA were associated with higher incidence of AMR. Patients with C3d + DSA had significantly higher incidence of AMR compared with patients with no DSA (P < 0.001) or patients with C3d-DSA (P = 0.02). Nine (36%) of 25 patients with AMR developed transplant coronary artery disease compared with 17 (15.9%) of 107 patients without AMR (P < 0.05). Among the 47 patients who received ventricular assistant device (VAD), 7 of 9 VAD+ patients with preformed DSA experienced AMR compared with 7 of 38 VAD+ patients without preformed DSA, indicating presensitization to donor HLA significantly increased the risk of AMR (P < 0.01).ConclusionsPreformed and posttransplant ndDSA were associated with AMR. C3d + DSA correlates with complement deposition on the graft and higher risk of AMR which may permit the application of personalized immunotherapy targeting the complement pathway.

Beta cell replacement has the potential to restore euglycemia in patients with insulin-dependent diabetes. Although great progress has been made in establishing allogeneic islet transplantation from deceased donors as the standard of care for those with the most labile diabetes, it is also clear that the deceased donor organ supply cannot possibly treat all those who could benefit from restoration of a normal beta cell mass, especially if immunosuppression were not required. Against this background, the International Pancreas and Islet Transplant Association in collaboration with the Harvard Stem Cell Institute, the Juvenile Diabetes Research Foundation (JDRF), and the Helmsley Foundation held a 2-day Key Opinion Leaders Meeting in Boston in 2016 to bring together experts in generating and transplanting beta cells derived from stem cells. The following summary highlights current technology, recent significant breakthroughs, unmet needs and roadblocks to stem cell-derived beta cell therapies, with the aim of spurring future preclinical collaborative investigations and progress toward the clinical application of stem cell-derived beta cells.

BackgroundKidney transplantation from hepatitis C seropositive (HCV+) donors may benefit hepatitis C RNA-positive (RNA+) candidates, but it is unclear how the willingness to be listed for and accept such kidneys affects waitlist and transplant outcomes.MethodsIn a single-center retrospective analysis, HCV+ transplant candidates (N = 169) listed from March 2004 to February 2015 were evaluated. All RNA+ candidates were offered the option to be listed for HCV+ donors. RNA- candidates were listed only for HCV- donors.ResultsFifty-seven patients (51% of all RNA+ transplant candidates) willing to accept HCV+ donors were listed for both HCV+ and HCV- donor kidneys. During 6-year follow up, 43 (75%) of 57 patients accepting HCV+ versus 19 (35%) of 55 patients not accepting HCV+ received a deceased donor kidney transplant (P < 0.0001). Multivariable analysis demonstrated that willingness to be listed for and accept HCV+ kidneys was associated with receiving deceased donor kidney transplant (P = 0.0016). Fewer patients accepting HCV+ donors (7 [12%] vs 16 [29%]) were removed from the list due to death or deteriorated medical condition (P = 0.0117). Posttransplant patient and graft survival rates were not significantly different. Overall patient survival since the listing (combined waitlist and posttransplant survival) was similar among the groups.ConclusionsHCV RNA+ candidates had better access to transplantation and similar overall survival before the era of widespread use of direct-acting anti-HCV agents.

BackgroundAspergillus colonization after lung transplant is associated with an increased risk of chronic lung allograft dysfunction (CLAD). We hypothesized that gene expression during Aspergillus colonization could provide clues to CLAD pathogenesis.MethodsWe examined transcriptional profiles in 3- or 6-month surveillance bronchoalveolar lavage fluid cell pellets from recipients with Aspergillus fumigatus colonization (n = 12) and without colonization (n = 10). Among the Aspergillus colonized, we also explored profiles in those who developed CLAD (n = 6) or remained CLAD-free (n = 6). Transcription profiles were assayed with the HG-U133 Plus 2.0 microarray (Affymetrix). Differential gene expression was based on an absolute fold difference of 2.0 or greater and unadjusted P value less than 0.05. We used NIH Database for Annotation, Visualization and Integrated Discovery for functional analyses, with false discovery rates less than 5% considered significant.ResultsAspergillus colonization was associated with differential expression of 489 probe sets, representing 404 unique genes. "Defense response" genes and genes in the "cytokine-cytokine receptor" Kyoto Encyclopedia of Genes and Genomes pathway were notably enriched in this list. Among Aspergillus colonized patients, CLAD development was associated with differential expression of 69 probe sets, representing 64 unique genes. This list was enriched for genes involved in "immune response" and "response to wounding", among others. Notably, both chitinase 3-like-1 and chitotriosidase were associated with progression to CLAD.ConclusionsAspergillus colonization is associated with gene expression profiles related to defense responses including cytokine signaling. Epithelial wounding, as well as the innate immune response to chitin that is present in the fungal cell wall, may be key in the link between Aspergillus colonization and CLAD.

BackgroundData are limited on marijuana use and its impact on liver transplant (LT) waitlist outcomes. We aimed to assess the risk of waitlist mortality/delisting and likelihood of LT among prior marijuana users and to determine the prevalence and factors associated with marijuana use.MethodsRetrospective cohort of adults evaluated for LT over 2 years at a large LT center. Marijuana use was defined by self-report in psychosocial assessment and/or positive urine toxicology. Ongoing marijuana use was not permitted for LT listing during study period.ResultsEight hundred eighty-four adults were evaluated, and 585 (66%) were listed for LT (median follow-up, 1.4 years; interquartile range, 0.5-2.0). Prevalence of marijuana use was 48%, with 7% being recent users and 41% prior users. Marijuana use had statistically significant association with alcoholic cirrhosis (incidence rate ratio [IRR], 1.9) and hepatitis C (IRR, 2.1) versus hepatitis B, tobacco use (prior IRR, 1.4; recent IRR, 1.3 vs never), alcohol use (never IRR 0.1; heavy use/abuse IRR 1.2 vs social), and illicit drug use (prior IRR, 2.3; recent, 1.9 vs never). In adjusted competing risk regression, marijuana use was not associated with the probability of LT (prior hazard ratio [HR], 0.9; recent HR, 0.9 vs never) or waitlist mortality/delisting (prior HR, 1.0; recent HR, 1.0 vs never). However, recent illicit drug use was associated with higher risk of death or delisting (HR, 1.8; P = 0.004 vs never).ConclusionsUnlike illicit drug use, marijuana use was not associated with worse outcomes on the LT waitlist. Prospective studies are needed to assess ongoing marijuana use on the LT waitlist and post-LT outcomes.

BackgroundRising alpha-fetoprotein (AFP) is a potential marker of worse prognosis after liver transplant (LT) for hepatocellular carcinoma (HCC), but prior studies relied on only 2 data points and were imprecise in assessing AFP slope. The aim of this study was to examine the association between AFP slope and post-LT HCC recurrence, with AFP slope estimated from multiple data points over time.MethodsOur cohort included 336 patients undergoing LT with Model for End Stage Liver Disease exception for HCC within Milan criteria from 2003 to 2013. Most (98%) had pre-LT locoregional therapy. AFP slope was estimated by fitting a regression line to the AFP levels over time.ResultsThe 1- and 5-year post-LT survivals were 94% and 77% and 1- and 5-year recurrence-free probabilities were 95% and 86%, respectively. In univariate analysis, HCC recurrence was significantly associated with microvascular invasion (hazard ratio [HR], 13.1; PMilan criteria (HR, 8.9; P7.5 (HR, 3.0; P=0.03) were significantly associated with HCC recurrence. AFP slope greater than 7.5 was also associated with microvascular invasion (odds ratio, 6.8; P=0.008).ConclusionsAFP slope increasing greater than 7.5 ng/mL per month despite locoregional therapy is associated with post-LT HCC recurrence and may serve as a surrogate for microvascular invasion. These findings support incorporating changes in the AFP into candidate selection for LT.

BACKGROUND:Focal segmental glomerulosclerosis (FSGS) is a common cause of end-stage renal disease with a high rate of recurrence after kidney transplantation. Several factors, such as white race, rapid progression, and previous allograft failure due to recurrence, were found to be risks of recurrence. Data are limited on the benefits of rituximab and/or therapeutic plasma exchange (TPE) in preventing recurrence. In this study, we sought to assess the efficacy of rituximab and TPE for the prevention and treatment of recurrent FSGS after kidney transplantation. METHODS:We enrolled 66 patients with FSGS in this prospective observational study and followed their outcomes. Patients with high risk for recurrence received preventative therapy with TPE and/or rituximab. RESULTS:Twenty-three (62%) of the 37 patients who received preventative therapy developed recurrence compared with 14 (51%) recurrences of the 27 patients who did not receive any therapy (P = 0.21). There was a trend for less relapse when rituximab was used as a therapy for recurrent FSGS (6/22 vs 9/18, P = 0.066). We used a clinical score of 5 values to assess the prediction of FSGS recurrence. A score of 3 or more had a predictive receiver operating characteristic curve of 0.72. Treatment with TPE and/or rituximab resulted in better allograft survival than historical studies. Allograft failure because of recurrent FSGS occurred in only 6 (9%) patients. CONCLUSIONS:Preventative therapies do not decrease the recurrence rate of recurrent FSGS. However, prompt treatment of recurrence with these therapies may result in improved outcomes.

Despite the rapidly increasing prevalence of obesity in the transplant population, the optimal management of obese liver transplant candidates remains undefined. Setting strict body mass index cutoffs for transplant candidacy remains controversial, with limited data to guide this practice. Body mass index is an imperfect measure of surgical risk in this population, partly due to volume overload and variable visceral adiposity. Weight loss before transplantation may be beneficial, but it remains important to avoid protein calorie malnutrition and sarcopenia. Intensive lifestyle modifications appear to be successful in achieving weight loss, though the durability of these interventions is not known. Pretransplant and intraoperative bariatric surgeries have been performed, but large randomized controlled trials are lacking. Traditional cardiovascular comorbidities are more prevalent in obese individuals and remain the basis for pretransplant cardiovascular evaluation and risk stratification. The recent US liver transplant experience demonstrates comparable patient and graft survival between obese and nonobese liver transplant recipients, but obesity presents important medical and surgical challenges during and after transplant. Specifically, obesity is associated with an increased incidence of wound infections, wound dehiscence, biliary complications and overall infection, and confers a higher risk of posttransplant obesity and metabolic syndrome-related complications. In this review, we examine current practices in the obese liver transplant population, offer recommendations based on the currently available data, and highlight areas where additional research is needed.

BackgroundIt has been postulated that short wait time before liver transplant (LT) for hepatocellular carcinoma (HCC) results in the inclusion of tumors with aggressive biology, but prolonged wait time could result in a shift to more aggressive tumor behavior. We therefore test the hypothesis that a wait time "sweet spot" exists with a lower risk for HCC recurrence compared with the other 2 extremes.MethodsThis multicenter study included 911 patients from 3 LT centers with short, medium, and long wait times (median of 4, 7, and 13 months, respectively) who received Model for End Stage Liver Disease exception listing for HCC from 2002 to 2012.ResultsWait time, defined as time from initial HCC diagnosis to LT, was less than 6 months in 32.4%, 6 to 18 months in 53.7%, and greater than 18 months in 13.9%. Waitlist dropout was observed in 18.4% at a median of 11.3 months. Probability of HCC recurrence at 1 and 5 years were 6.4% and 15.5% with wait time of less than 6 or greater than 18 months (n = 343) versus 4.5% and 9.8% with wait time of 6 to 18 months (n = 397), respectively (P = 0.049). When only pre-LT factors were considered, wait time of less than 6 or greater than 18 months (HR, 1.6; P = 0.043) and AFP greater than 400 at HCC diagnosis (HR, 3.0; P < 0.001) predicted HCC recurrence in multivariable analysis.ConclusionsThis large multicenter study provides evidence of an association between very short (18 months) wait times and an increased risk for HCC recurrence post-LT. The so-called sweet spot of 6 to 18 months should be the target to minimize HCC recurrence.

BackgroundThe waiting list for kidney transplantation is long. The creation of "vouchers" for future kidney transplants enables living donation to occur when optimal for the donor and transplantation to occur later, when and if needed by the recipient.MethodsThe donation of a kidney at a time that is optimal for the donor generates a "voucher" that only a specified recipient may redeem later when needed. The voucher provides the recipient with priority in being matched with a living donor from the end of a future transplantation chain. Besides its use in persons of advancing age with a limited window for donation, vouchers remove a disincentive to kidney donation, namely, a reluctance to donate now lest one's family member should need a transplant in the future.ResultsWe describe the first three voucher cases, in which advancing age might otherwise have deprived the donors the opportunity to provide a kidney to a family member. These 3 voucher donations functioned in a nondirected fashion and triggered 25 transplants through kidney paired donation across the United States.ConclusionsThe provision of a voucher to potential recipients whose need for a transplant makes them "chronologically incompatible" with their donors may increase the number of living donor transplants.

BackgroundInconsistencies in outcome reporting and frequent omission of patient-centered outcomes can diminish the value of trials in treatment decision making. We identified critically important outcome domains in kidney transplantation based on the shared priorities of patients/caregivers and health professionals.MethodsIn a 3-round Delphi survey, patients/caregivers and health professionals rated the importance of outcome domains for trials in kidney transplantation on a 9-point Likert scale and provided comments. During rounds 2 and 3, participants rerated the outcomes after reviewing their own score, the distribution of the respondents' scores, and comments. We calculated the median, mean, and proportion rating 7 to 9 (critically important), and analyzed comments thematically.ResultsOne thousand eighteen participants (461 [45%] patients/caregivers and 557 [55%] health professionals) from 79 countries completed round 1, and 779 (77%) completed round 3. The top 8 outcomes that met the consensus criteria in round 3 (mean, ≥7.5; median, ≥8; proportion, >85%) in both groups were graft loss, graft function, chronic rejection, acute rejection, mortality, infection, cancer (excluding skin), and cardiovascular disease. Compared with health professionals, patients/caregivers gave higher priority to 6 outcomes (mean difference of 0.5 or more): skin cancer, surgical complications, cognition, blood pressure, depression, and ability to work. We identified 5 themes: capacity to control and inevitability, personal relevance, debilitating repercussions, gaining awareness of risks, and addressing knowledge gaps.ConclusionsGraft complications and severe comorbidities were critically important for both stakeholder groups. These stakeholder-prioritized outcomes will inform the core outcome set to improve the consistency and relevance of trials in kidney transplantation.

BackgroundTreatment decisions in kidney transplantation requires patients and clinicians to weigh the benefits and harms of a broad range of medical and surgical interventions, but the heterogeneity and lack of patient-relevant outcomes across trials in transplantation makes these trade-offs uncertain, thus, the need for a core outcome set that reflects stakeholder priorities.MethodsWe convened 2 international Standardized Outcomes in Nephrology-Kidney Transplantation stakeholder consensus workshops in Boston (17 patients/caregivers; 52 health professionals) and Hong Kong (10 patients/caregivers; 45 health professionals). In facilitated breakout groups, participants discussed the development and implementation of core outcome domains for trials in kidney transplantation.ResultsSeven themes were identified. Reinforcing the paramount importance of graft outcomes encompassed the prevailing dread of dialysis, distilling the meaning of graft function, and acknowledging the terrifying and ambiguous terminology of rejection. Reflecting critical trade-offs between graft health and medical comorbidities was fundamental. Contextualizing mortality explained discrepancies in the prioritization of death among stakeholders-inevitability of death (patients), preventing premature death (clinicians), and ensuring safety (regulators). Imperative to capture patient-reported outcomes was driven by making explicit patient priorities, fulfilling regulatory requirements, and addressing life participation. Specificity to transplant; feasibility and pragmatism (long-term impacts and responsiveness to interventions); and recognizing gradients of severity within outcome domains were raised as considerations.ConclusionsStakeholders support the inclusion of graft health, mortality, cardiovascular disease, infection, cancer, and patient-reported outcomes (ie, life participation) in a core outcomes set. Addressing ambiguous terminology and feasibility is needed in establishing these core outcome domains for trials in kidney transplantation.

BackgroundBK virus infection remains an important cause of loss of allograft function after kidney transplantation. We sought to determine whether polyfunctional T cells secreting multiple cytokines simultaneously, which have been shown to be associated with viral control, could be detected early after start of BK viremia, which would provide insight into the mechanism of successful antiviral control.MethodsPeripheral blood mononuclear cells collected during episodes of BK viral replication were evaluated by multiparameter flow cytometry after stimulation by overlapping peptide pools of BK virus antigen to determine frequency of CD8+ and CD4+ T cells expressing 1 or more cytokines simultaneously, as well as markers of T-cell activation, exhaustion, and maturation.ResultsBK virus controllers, defined as those with episodes of BK viremia of 3 months or less, had an 11-fold increase in frequency of CD8+ polyfunctional T cells expressing multiple cytokines, as compared with patients with prolonged episodes of BK viremia. Patients with only low level BK viremia expressed low frequencies of polyfunctional T cells. Polyfunctional T cells were predominantly of the effector memory maturation subtype and expressed the cytotoxicity marker CD107a.ConclusionsNoninvasive techniques for immune assessment of peripheral blood can provide insight into the mechanism of control of BK virus replication and may allow for future patient risk stratification and customization of immune suppression at the onset of BK viremia.

BackgroundMost current scoring tools to predict allograft and patient survival upon kidney transplantion are based on variables collected posttransplantation. We developed a novel score to predict posttransplant outcomes using pretransplant information including routine laboratory data available before or at the time of transplantation.MethodsLinking the 5-year patient data of a large dialysis organization to the Scientific Registry of Transplant Recipients, we identified 15 125 hemodialysis patients who underwent first deceased transplantion. Prediction models were developed using Cox models for (a) mortality, (b) allograft loss (death censored), and (c) combined death or transplant failure. The cohort was randomly divided into a two thirds set (Nd = 10 083) for model development and a one third set (Nv = 5042) for validation. Model predictive discrimination was assessed using the index of concordance, or C statistic, which accounts for censoring in time-to-event models (a-c). We used the bootstrap method to assess model overfitting and calibration using the development dataset.ResultsPatients were 50 ± 13 years of age and included 39% women, 15% African Americans, and 36% persons with diabetes. For prediction of posttransplant mortality and graft loss, 10 predictors were used (recipients' age, cause and length of end-stage renal disease, hemoglobin, albumin, selected comorbidities, race and type of insurance as well as donor age, diabetes status, extended criterion donor kidney, and number of HLA mismatches). The new model (www.TransplantScore.com) showed the overall best discrimination (C-statistics, 0.70; 95% confidence interval [95% CI], 0.67-0.73 for mortality; 0.63; 95% CI, 0.60-0.66 for graft failure; 0.63; 95% CI, 0.61-0.66 for combined outcome).ConclusionsThe new prediction tool, using data available before the time of transplantation, predicts relevant clinical outcomes and may perform better to predict patients' graft survival than currently used tools.

BackgroundHepatitis C virus (HCV)(+) donors represent an effective strategy to increase liver donor availability to HCV-infected recipients. However, many HCV(+) transplant candidates are now receiving treatment with direct-acting anti-viral (DAA) agents that lower the risk of posttransplant HCV recurrence but could make the patient ineligible for HCV(+) livers.MethodsWe compared pretransplant DAA treatment versus deferred DAA treatment using a cost-effectiveness decision analysis model to estimate incremental cost-effectiveness ratios (cost per quality-adjusted life year gained) from the societal perspective across a range of HCV(+) liver availability rates. For practical considerations, the population modeled was restricted to well-compensated HCV(+) cirrhotics listed for liver transplantation with hepatocellular carcinoma MELD exception points.ResultsUnder base case conditions, the deferred DAA treatment strategy was found to be the "dominant" strategy. That is, it provided superior health outcomes at cost savings compared to the pretransplant DAA treatment strategy. The pretransplant DAA treatment strategy trended towards cost-effectiveness as HCV(+) donor liver availability declined. However, only in 1 scenario that was highly optimized for favorable outcomes in the pretransplant DAA treatment arm (low availability of HCV(+) organs, low cost of DAA treatment, high cost of HCV recurrence) was the incremental cost-effectiveness ratio associated with HCV DAA treatment before transplant less than US $150 000/quality-adjusted life-year gained.ConclusionsDeferring HCV treatment until after liver transplant and maintaining access to the expanded pool of HCV(+) donors appears to be the most cost-effective strategy for well-compensated HCV-infected cirrhotics listed for liver transplantation with hepatocellular carcinoma, even in geographic areas of relatively low HCV(+) donor availability.

BackgroundWe examined if African or Asian ethnicity was associated with lower access to kidney transplantation (KT) in a Canadian setting.MethodsPatients referred for KT to the Toronto General Hospital from January 1, 2003, to December 31, 2012, who completed social work assessment, were included (n = 1769). The association between ethnicity and the time from referral to completion of KT evaluation or receipt of a KT were examined using Cox proportional hazards models.ResultsAbout 54% of the sample was white, 13% African, 11% East Asian, and 11% South Asian; 7% had "other" (n = 121) ethnic background. African Canadians (hazard ratio [HR], 0.75; 95% CI: 0.62-0.92]) and patients with "other" ethnicity (HR, 0.71; 95% CI, 0.55-0.92) were less likely to complete the KT evaluation compared with white Canadians, and this association remained statistically significant in multivariable adjusted models. Access to KT was significantly reduced for all ethnic groups assessed compared with white Canadians, and this was primarily driven by differences in access to living donor KT. The adjusted HRs for living donor KT were 0.35 (95% CI, 0.24-0.51), 0.27 (95% CI, 0.17-0.41), 0.43 (95% CI, 0.30-0.61), and 0.34 (95% CI, 0.20-0.56) for African, East or South Asian Canadians and for patients with "other" ethnic background, respectively.ConclusionsSimilar to other jurisdictions, nonwhite patients face barriers to accessing KT in Canada. This inequity is very substantial for living donor KT. Further research is needed to identify if these inequities are due to potentially modifiable barriers.

BackgroundRejection remains the leading cause of allograft loss, and a major barrier to improving long-term outcomes after intestinal transplantation. Our aim is to define the prevalence and investigate the role of donor-specific antibody (DSA) on intestinal graft outcomes.MethodsThe study includes 109 transplants performed in 95 recipients at a single center. Patients were screened for DSA pretransplant, monitored regularly posttransplant and when clinically indicated using the single-antigen bead Luminex assay. Standard induction immunosuppression was with interleukin-2 receptor antagonists, and antithymocyte globulin in high-risk recipients. Maintenance regimens were tacrolimus-based.ResultsPretransplant DSA was detected in 12 (11%) recipients with 50% continuing to have circulating antibodies posttransplant. An additional 24 (25%) patients developed de novo DSA, and of these, 71% had persistent antibodies. Recipients with preformed DSA demonstrated elevated risks of early graft failure, whereas those with de novo DSA experienced accelerated graft loss once DSA was detected, reaching a 28% failure rate within 2 years. HLA-DQ mismatch is a significant risk factor for de novo DSA emergence, whereas the persistence of antibodies is predicted by DSA strength and specificity. Although inclusion of the liver in the intestinal allograft imparts an immunological advantage against rejection-related graft loss, this protective effect was lost among recipients with persistent DSA.ConclusionsThe presence of DSA is associated with inferior graft outcomes among intestinal transplant recipients. An enhanced understanding of the mechanisms by which DSA causes allograft injury, and effective strategies targeting humoral immune reactivity are needed to improve long-term intestinal graft outcomes.

BackgroundThe liver as transplantation site for human pancreatic islets is a harsh microenvironment for islets and it lacks the ability to retrieve the graft. A retrievable, extrahepatic transplantation site that mimics the pancreatic environment is desired. Ideally, this transplantation site should be located subdermal for easy surgical-access but this never resulted in normoglycemia. Here, we describe the design and efficacy of a novel prevascularized, subcutaneously implanted, retrievable poly (D,L-lactide-co-ε-caprolactone) scaffold.MethodThree dosages of rat islets, that is, 400, 800, and 1200, were implanted in immune compromised mice to test the efficacy (n = 5). Islet transplantation under the kidney capsule served as control (n = 5). The efficacy was determined by nonfasting blood glucose measurements and glucose tolerance tests.ResultsTransplantation of 800 (n = 5) and 1200 islets (n = 5) into the scaffold reversed diabetes in respectively 80 and 100% of the mice within 6.8 to 18.5 days posttransplant. The marginal dose of 400 islets (n = 5) induced normoglycemia in 20%. The glucose tolerance test showed major improvement of the glucose clearance in the scaffold groups compared to diabetic controls. However, the kidney capsule was slightly more efficacious because all 800 (n = 5) and 1200 islets (n = 5) recipients and 40% of the 400 islets (n = 5) recipients became normoglycemic within 8 days. Removal of the scaffolds or kidney grafts resulted in immediate return to hyperglycemia. Normoglycemia was not achieved with 1200 islets in the unmodified skin group.ConclusionsOur findings demonstrate that the prevascularized poly (D,L-lactide-co-ε-caprolactone) scaffold maintains viability and function of islets in the subcutaneous site.

BackgroundCommunity-acquired respiratory virus (CARV) infections occur frequently after lung transplantation and may adversely impact outcomes. We hypothesized that while asymptomatic carriage would not increase the risk of chronic lung allograft dysfunction (CLAD) and graft loss, severe infection would.MethodsAll lung transplant cases between January 2000 and July 2013 performed at our center were reviewed for respiratory viral samples. Each isolation of virus was classified according to clinical level of severity: asymptomatic, symptomatic without pneumonia, and viral pneumonia. Multivariate Cox modeling was used to assess the impact of CARV isolation on progression to CLAD and graft loss.ResultsFour thousand four hundred eight specimens were collected from 563 total patients, with 139 patients producing 324 virus-positive specimens in 245 episodes of CARV infection. Overall, the risk of CLAD was elevated by viral infection (hazard ratio [HR], 1.64; P < 0.01). This risk, however, was due to viral pneumonia alone (HR, 3.94; P < 0.01), without significant impact from symptomatic viral infection (HR, 0.97; P = 0.94) nor from asymptomatic viral infection (HR, 0.99; P = 0.98). The risk of graft loss was not increased by asymptomatic CARV infection (HR, 0.74; P = 0.37) nor symptomatic CARV infection (HR, 1.39; P = 0.41). Viral pneumonia did, however, significantly increase the risk of graft loss (HR, 2.78; P < 0.01).ConclusionsWith respect to CARV, only viral pneumonia increased the risk of both CLAD and graft loss after lung transplantation. In the absence of pneumonia, respiratory viruses had no impact on measured outcomes.

BackgroundSolid organ transplant recipients have heightened risk for diffuse large B cell lymphoma (DLBCL). The role of donor-recipient HLA mismatch and recipient HLA type on DLBCL risk are not well established.MethodsWe examined 172 231 kidney, heart, pancreas, and lung recipients transplanted in the United States between 1987 and 2010, including 902 with DLBCL. Incidence rate ratios (IRRs) were calculated using Poisson regression for DLBCL risk in relation to HLA mismatch, types, and zygosity, adjusting for sex, age, race/ethnicity, year, organ, and transplant number.ResultsCompared with recipients who had 2 HLA-DR mismatches, those with zero or 1 mismatch had reduced DLBCL risk, (zero: IRR, 0.76, 95% confidence interval [95% CI], 0.61-0.95; one: IRR, 0.83; 95% CI, 0.69-1.00). In stratified analyses, recipients matched at either HLA-A, -B, or -DR had a significantly reduced risk of late-onset (>2 years after transplantation), but not early-onset DLBCL, and there was a trend for decreasing risk with decreasing mismatch across all 3 loci (P = 0.0003). Several individual recipient HLA-A, -B, -C, -DR, and -DQ antigens were also associated with DLBCL risk, including DR13 (IRR, 0.74; 95% CI, 0.57-0.93) and B38 (IRR, 1.48; 95% CI, 1.10-1.93), confirming prior findings that these 2 antigens are associated with risk of infection-associated cancers.ConclusionsIn conclusion, variation in HLA is related to susceptibility to DLBCL, perhaps reflecting intensity of immunosuppression, control of Epstein-Barr virus infection among transplant recipients or chronic immune stimulation.

BackgroundThe probability of liver transplant and death on the waiting list in the United States varies greatly by donation service area (DSA) due to geographic differences in availability of organs and allocation of priority points, making it difficult for providers to predict likely outcomes after listing. We aimed to develop an online calculator to report outcomes by region and patient characteristics.MethodsUsing the Scientific Registry of Transplant Recipients database, we included all prevalent US adults aged 18 years or older waitlisted for liver transplant, examined on 24 days at least 30 days apart over a 2-year period. Outcomes were determined at intervals of 30 to 365 days. Outcomes are reported by transplant program, DSA, region, and the nation for comparison, and can be shown by allocation or by laboratory model for end-stage liver disease (MELD) score (6-14, 15-24, 25-29, 30-34, 35-40), age, and blood type.ResultsOutcomes varied greatly by DSA; for candidates with allocation MELD 25-29, the 25th and 75th percentiles of liver transplant probability were 30% and 67%, respectively, at 90 days. Corresponding percentiles for death or becoming too sick to undergo transplant were 5% and 9%. Outcomes also varied greatly for candidates with and without MELD exception points.ConclusionsThe waitlist outcome calculator highlights ongoing disparities in access to liver transplant and may assist providers in understanding and counseling their patients about likely outcomes on the waiting list.

BackgroundPolyomavirus nephropathy (PVAN) is a common cause of kidney allograft dysfunction and loss. To identify PVAN-specific gene expression and underlying molecular mechanisms, we analyzed kidney biopsies with and without PVAN.MethodsThe study included 168 posttransplant renal allograft biopsies (T cell-mediated rejection [TCMR] = 26, PVAN = 10, normal functioning graft = 73, and interstitial fibrosis/tubular atrophy = 59) from 168 unique kidney allograft recipients. We performed gene expression assays and bioinformatics analysis to identify a set of PVAN-specific genes. Validity and relevance of a subset of these genes are validated by quantitative polymerase chain reaction and immunohistochemistry.ResultsUnsupervised hierarchical clustering analysis of all the biopsies revealed high similarity between PVAN and TCMR gene expression. Increased statistical stringency identified 158 and 252 unique PVAN and TCMR injury-specific gene transcripts respectively. Although TCMR-specific genes were overwhelmingly involved in immune response costimulation and TCR signaling, PVAN-specific genes were mainly related to DNA replication process, RNA polymerase assembly, and pathogen recognition receptors. A principal component analysis (PCA) using these genes further confirmed the most optimal separation between the 3 different clinical phenotypes. Validation of 4 PVAN-specific genes (RPS15, complement factor D, lactotransferrin, and nitric oxide synthase interacting protein) by quantitative polymerase chain reaction and confirmation by immunohistochemistry of 2 PVAN-specific proteins with antiviral function (lactotransferrin and IFN-inducible transmembrane 1) was done.ConclusionsIn conclusion, even though PVAN and TCMR kidney allografts share great similarities on gene perturbation, PVAN-specific genes were identified with well-known antiviral properties that provide tools for discerning PVAN and AR as well as attractive targets for rational drug design.

BackgroundPrevious studies have indicated that patients on maintenance hemodialysis have worse survival compared with kidney transplant (KTx) recipients. However, none of these studies have compared mortality of the US patients using alternative dialysis modalities such as home hemodialysis (HHD) with KTx recipients.MethodsComparing patients who started HHD with those who received kidney transplantation in the United States between 2007 and 2011, we created a 1:1 propensity score-matched cohort of 4000 patients and examined the association between treatment modality and all-cause mortality using Cox proportional hazard models.ResultsThe mean ± SD age of the propensity score-matched HHD and KTx patients at baseline were 54 ± 15 years and 54 ± 14 years, 65% were men (both groups), 70% and 72% of patients were whites, and 19% were African American (both groups), respectively. Over 5 years of follow-up, HHD patients had 4 times higher mortality risk compared with KTx recipients in the entire patient population (hazard ratio [HR], 4.06; 95% confidence interval [95% CI], 3.27-5.04); total event number, 411), and similar difference was found across each race stratum. However, during the first year of therapy, although the white HHD patients had higher mortality risk (HR, 4.21; 95% CI, 3.10-5.73; total event number, 332) compared with their KTx counterparts, there was no significant difference in mortality risk between African American HHD and KTx patients (HR, 1.62; 95% CI, 0.77-3.39; total event number, 55). This result was consistent across different types of kidney donors.ConclusionsThe HHD patients appear to have 4 times higher mortality compared with KTx recipients regardless of the type of kidney donor. Further studies are needed to understand the reasons underlying racial differenes during the first year of therapy.

BackgroundAcute cellular rejection is a major cause of morbidity after lung transplantation. Because regulatory T (Treg) cells limit rejection of solid organs, we hypothesized that donor-reactive Treg increase after transplantation with development of partial tolerance and decrease relative to conventional CD4 (Tconv) and CD8 T cells during acute cellular rejection.MethodsTo test these hypotheses, we prospectively collected 177 peripheral blood mononuclear cell specimens from 39 lung transplant recipients at the time of transplantation and during bronchoscopic assessments for acute cellular rejection. We quantified the proportion of Treg, CD4 Tconv, and CD8 T cells proliferating in response to donor-derived, stimulated B cells. We used generalized estimating equation-adjusted regression to compare donor-reactive T cell frequencies with acute cellular rejection pathology.ResultsAn average of 16.5 ± 9.0% of pretransplantation peripheral blood mononuclear cell Treg cell were donor-reactive, compared with 3.8% ± 2.9% of CD4 Tconv and 3.4 ± 2.6% of CD8 T cells. These values were largely unchanged after transplantation. Donor-reactive CD4 Tconv and CD8 T cell frequencies both increased 1.5-fold (95% confidence interval [95% CI], 1.3-1.6; P < 0.001 and 95% CI, 1.2-1.6; P = 0.007, respectively) during grade A2 rejection compared with no rejection. Surprisingly, donor-reactive Treg frequencies increased by 1.7-fold (95% CI, 1.4-1.8; P < 0.001).ConclusionsContrary to prediction, overall proportions of donor-reactive Treg cells are similar before and after transplantation and increase during grade A2 rejection. This suggests how A2 rejection can be self-limiting. The observed increases over high baseline proportions in donor-reactive Treg were insufficient to prevent acute lung allograft rejection.

BackgroundThe dual role of B cells as drivers and suppressors of the immune responses have underscored the need to trace the fate of B cells recognizing donor major histocompatibility complex class I and class II after allograft transplantation.MethodsIn this study, we used donor class II tetramers to trace the fate of I-E-specific B cells after immunization with BALB/c spleen cells or cardiac transplantation, in naive or sensitized C57BL/6 recipients. We combined this approach with genetic lineage tracing of memory B cells in activation-induced cytidine deaminase regulated Cre transgenic mice crossed to the ROSA26-enhanced yellow fluorescent protein reporter mice to track endogenous I-E-specific memory B cell generation.ResultsImmunization with BALB/c splenocytes or heart transplantation induced an expansion and differentiation of I-E-specific B cells into germinal center B cells, whereas BALB/c heart transplantation into sensitized recipients induced the preferential differentiation into antibody-secreting cells. A 10.8-fold increase in the frequency of I-E-specific memory B cells was observed by day 42 postimmunization. Treatment with CTLA4-Ig starting on day 0 or day 7 postimmunization abrogated I-E-specific memory B cell generation and sensitized humoral responses, but not if treatment commenced on day 14.ConclusionsThe majority of donor-specific memory B cells are generated between days 7 and 14 postimmunization, thus revealing a flexible timeframe whereby delayed CTLA4-Ig administration can inhibit sensitization and the generation of memory graft-reactive B cells.

BackgroundEarly allograft dysfunction (EAD) after living donor liver transplantation (LDLT) has often been attributed to inadequate graft size, and termed small-for-size syndrome. Early allograft dysfunction definitions include a variable constellation of findings, including hyperbilirubinemia, coagulopathy, encephalopathy, and ascites formation. Among putative causes of EAD after LDLT are excessive portal pressure and/or flow. Our objective was to evaluate patterns of EAD after LDLT.MethodsIn this study, 631 LDLT recipients were monitored for complications, EAD (defined by postoperative day 7 bilirubin >10 mg/dL or international normalized ratio >1.6), and graft failure. Approximately 200 had portal venous and arterial pressure and flow measurements before and after LDLT. Portal inflow modification (splenic artery ligation, hemiportocaval shunt, or splenectomy) was performed at the discretion of the operating surgeon. Associations between EAD and recipient, donor, and transplant factors were examined using multivariable logistic regression.ResultsRisk of EAD was associated with left lobe grafts, lower graft weight among left lobes, higher preoperative bilirubin, higher portal reperfusion pressure, higher donor age, and higher donor body mass index. The risk of graft loss within the first 90 days was 5.2 times higher for recipients with EAD versus those without EAD (P < 0.001).ConclusionsEarly allograft dysfunction can be defined using postoperative day 7 laboratory values that are highly predictive of early graft failure within 90 days. Risk factors associated with EAD after LDLT include: graft type and size, preoperative bilirubin, portal reperfusion pressure, donor age, and donor body mass index.

BackgroundEmbryonic stem cell (ESC)-derived β cells hold the promise of providing a renewable source of tissue for the treatment of insulin-dependent diabetes. Encapsulation may allow ESC-derived β cells to be transplanted without immunosuppression, thus enabling wider application of this therapy.MethodsIn this study, we investigated the immunogenicity of mouse pancreatic progenitor cells and efficacy of a new macroencapsulation device in protecting these cells against alloimmune and autoimmune responses in mouse models.ResultsMouse pancreatic progenitor cells activated the indirect but not the direct pathway of alloimmune response and were promptly rejected in immune competent hosts. The new macroencapsulation device abolished T cell activation induced by allogeneic splenocytes and protected allogeneic MIN6 β cells and pancreatic progenitors from rejection even in presensitized recipients. In addition, the device was effective in protecting MIN6 cells in spontaneously diabetic nonobese diabetic recipients against both alloimmune and recurring autoimmune responses.ConclusionsOur results demonstrate that macroencapsulation can effectively prevent immune sensing and rejection of allogeneic pancreatic progenitor cells in fully sensitized and autoimmune hosts.