Loss of end‐differentiated β‐cell phenotype following pancreatic islet transplantation

Replacement of pancreatic β‐cells through deceased donor islet transplantation is a proven therapy for preventing recurrent life‐threatening hypoglycemia in type 1 diabetes. Although near‐normal glucose levels and insulin independence can be maintained for many years following successful islet transplantation, restoration of normal functional β‐cell mass has remained elusive. It has recently been proposed that dedifferentiation/plasticity towards other endocrine phenotypes may play an important role in stress‐induced β‐cell dysfunction in type 2 diabetes. Here we report loss of end‐differentiated β‐cell phenotype in 2 intraportal islet allotransplant recipients. Despite excellent graft function and sustained insulin independence, all examined insulin‐positive cells had lost expression of the end‐differentiation marker, urocortin‐3, or appeared to co‐express the α‐cell marker, glucagon. In contrast, no insulin⁺/urocortin‐3^? cells were seen in nondiabetic deceased donor control pancreatic islets. Loss of end‐differentiated phenotype may facilitate β‐cell survival during the stresses associated with islet isolation and culture, in addition to sustained hypoxia following engraftment. As further refinements in islet isolation and culture are made in parallel with exploration of alternative β‐cell sources, graft sites, and ultimately fully vascularized bioengineered insulin‐secreting microtissues, differentiation status immunostaining provides a novel tool to assess whether fully mature β‐cell phenotype has been maintained.     

Outcomes of organ transplants when the donor is a prior recipient

Organ shortage continues to challenge the field of transplantation. One potential group of donors are those who have been transplant recipients themselves, or Organ Donation After Transplant (ODAT) donors. We conducted a retrospective cohort study to describe ODAT donors and to compare outcomes of ODAT grafts versus conventional grafts. From October 1, 1987 to June 30, 2015, 517 former recipients successfully donated 803 organs for transplant. Former kidney recipients generally survived a median of approximately 4 years before becoming an ODAT donor whereas liver, lung, and heart recipients generally survived less than a month prior to donation. In the period June 1, 2005 to December 31, 2014, liver grafts from ODAT donors had a significantly higher risk of graft failure compared to non‐ODAT liver transplants (P = .008). Kidney grafts donated by ODAT donors whose initial transplant occurred >1 year prior were associated with significantly increased graft failure (P = .012). Despite increased risk of graft failure amongst certain ODAT grafts, 5‐year survival was still high. ODAT donors should be considered another form of expanded criteria donor under these circumstances.     

Impact of spontaneous donor hypothermia on graft outcomes after kidney transplantation

A previous donor intervention trial found that therapeutic hypothermia reduced delayed graft function (DGF) after kidney transplantation. This retrospective cohort study nested in the randomized dopamine trial (ClinicalTrials.gov identifier: NCT000115115) investigates the effects of spontaneous donor hypothermia (core body temperature <36°C) on initial kidney graft function, and evaluates 5‐year graft survival. Hypothermia assessed by a singular measurement in the intensive care unit 4‐20 hours before procurement was associated with less DGF after kidney transplantation (odds ratio [OR] 0.56, 95% confidence interval [CI] 0.34‐0.91). The benefit was greater when need for more than a single posttransplant dialysis session was analyzed (OR 0.48, 95%CI 0.28‐0.82). Donor dopamine ameliorated dialysis requirement independently from hypothermia in a temporal relationship with exposure (OR 0.93, 95%CI 0.87‐0.98, per hour). A lower core body temperature in the donor was associated with lower serum creatinine levels before procurement, which may reflect lower systemic inflammation and attenuated renal injury from brain death. Despite a considerable effect on DGF, our study failed to demonstrate a graft survival advantage (hazard ratio [HR] 0.83, 95%CI 0.54‐1.27), whereas dopamine treatment was associated with improved long‐term outcome (HR 0.95, 95%CI 0.91‐0.99 per hour).     

Factors associated with perceived donation‐related financial burden among living kidney donors

The perception of living kidney donation–related financial burden affects willingness to donate and the experience of donation, yet no existing tools identify donors who are at higher risk of perceived financial burden. We sought to identify characteristics that predicted higher risk of perceived financial burden. We surveyed 51 living kidney donors (LKDs) who donated from 01/2015 to 3/2016 about socioeconomic characteristics, predonation cost concerns, and perceived financial burden. We tested associations between both self‐reported and ZIP code–level characteristics and perceived burden using Fisher's exact test and bivariate modified Poisson regression. Donors who perceived donation‐related financial burden were less likely to have an income above their ZIP code median (14% vs. 72%, P = .006); however, they were more likely than donors who did not perceive burden to rent their home (57% vs. 16%, P = .03), have an income <$60 000 (86% vs. 20%, P = .002), or have had predonation cost concerns (43% vs. 7%, P = .03). Perceived financial burden was 3.6‐fold as likely among those with predonation cost concerns and 10.6‐fold as likely for those with incomes <$60 000. Collecting socioeconomic characteristics and asking about donation‐related cost concerns prior to donation might allow transplant centers to target financial support interventions toward potential donors at higher risk of perceiving donation‐related financial burden.     

Functional status,healthcare utilization,and the costs of liver transplantation

The Model for End‐Stage Liver Disease (MELD) score predicts higher transplant healthcare utilization and costs; however, the independent contribution of functional status towards costs is understudied. The study objective was to evaluate the association between functional status, as measured by Karnofsky Performance Status (KPS), and liver transplant (LT) costs in the first posttransplant year. In a cohort of 598 LT recipients from July 1, 2009 to November 30, 2014, multivariable models assessed associations between KPS and outcomes. LT recipients needing full assistance (KPS 10%‐40%) vs being independent (KPS 80%‐100%) were more likely to be discharged to a rehabilitation facility after LT (22% vs 3%) and be rehospitalized within the first posttransplant year (78% vs 57%), all P < .001. In adjusted generalized linear models, in addition to MELD (P < .001), factors independently associated with higher 1‐year post‐LT transplant costs were older age, poor functional status (KPS 10%‐40%), living donor LT, pre‐LT hemodialysis, and the donor risk index (all P < .001). One‐year survival for patients in the top cost decile was 83% vs 93% for the rest of the cohort (log rank P < .001). Functional status is an important determinant of posttransplant resource utilization; therefore, standardized measurements of functional status should be considered to optimize candidate selection and outcomes.     

Short‐term adverse effects of early subclinical allograft inflammation in kidney transplant recipients with a rapid steroid withdrawal protocol

The impact of subclinical inflammation (SCI) noted on early kidney allograft biopsies remains unclear. This study evaluated the outcome of SCI noted on 3‐month biopsy. A total of 273/363 (75%) kidney transplant recipients with a functioning kidney underwent allograft biopsies 3‐months posttransplant. Among those with stable allograft function at 3 months, 200 biopsies that did not meet the Banff criteria for acute rejection were identified. These were Group I: No Inflammation (NI, n = 71) and Group II: Subclinical Inflammation (SCI, n = 129). We evaluated differences in kidney function at 24‐months and allograft histology score at 12‐month biopsy. SCI patients had a higher serum creatinine (1.6 ± 0.7 vs 1.38 ± 0.45; P = .02) at 24‐months posttransplant, and at last follow‐up at a mean of 42.5 months (1.69 ± 0.9 vs 1.46 ± 0.5 mg/dL; P = .027). The allograft chronicity score (ci + ct + cg + cv) at 12‐months posttransplant was higher in the SCI group (2.4 ± 1.35 vs 1.9 ± 1.2; P = .02). The incidence of subsequent rejections within the first year in SCI and NI groups was 24% vs 10%, respectively (P = .015). De novo donor‐specific antibody within 12 months was more prevalent in the SCI group (12/129 vs 1/71, P = .03). SCI is likely not a benign finding and may have long‐term implications for kidney allograft function.     

Isolated vascular “v” lesions in liver allografts: How to approach this unusual finding

According to the Banff criteria for kidney allografts, isolated vascular or “v” lesions are defined as intimal inflammation, age‐inappropriate fibro‐intimal hyperplasia, or both, without the presence of associated interstitial T cell‐mediated rejection (TCMR). In general, these lesions portend a worse outcome for kidney allografts, particularly in those where the “v” lesions are identified in patients with coexistent donor specific antibodies (DSA) or later after transplantation. Although affected arteries are rarely sampled in liver allograft biopsies, we identified nine patients at a mean of 1805 days posttransplantation and compared these to matched controls. Almost half (4 of 9) of the study patient biopsies showed inflammatory arteritis associated with focal or diffuse C4d positivity, which was not observed in matched controls. One “v” lesion patient progressed to rejection‐related graft failure and two developed moderate/severe TCMR in subsequent biopsies, whereas only one rejection episode occurred in follow‐up biopsies, and no rejection‐related deaths or graft failures were detected in controls. In conclusion, patients with liver allograft isolated “v” lesions should undergo further evaluation and closer follow‐up for impending TCMR and/or underlying co‐existent chronic antibody‐mediated rejection (AMR).     

Preemptive treatment of early donor‐specific antibodies with IgA‐ and IgM‐enriched intravenous human immunoglobulins in lung transplantation

This retrospective study presents our 4‐year experience of preemptive treatment of early anti‐HLA donor specific antibodies with IgA‐ and IgM‐enriched immunoglobulins. We compared outcomes between patients with antibodies and treatment (case patients) and patients without antibodies (control patients). Records of patients transplanted at our institution between March 2013 and November 2017 were reviewed. The treatment protocol included one single 2 g/kg immunoglobulin infusion followed by successive 0.5 g/kg infusions for a maximum of 6 months, usually combined with a single dose of anti‐CD20 antibody and, in case of clinical rejection or positive crossmatch, with plasmapheresis or immunoabsorption. Among the 598 transplanted patients, 128 (21%) patients formed the case group and 452 (76%) the control group. In 116 (91%) patients who completed treatment, 106 (91%) showed no antibodies at treatment end. Fourteen (13%) patients showed antibody recurrence thereafter. In case versus control patients and at 4‐year follow‐up, respectively, graft survival (%) was 79 versus 81 (P = .59), freedom (%) from biopsy‐confirmed rejection 57 versus 53 (P = .34), and from chronic lung allograft dysfunction 82 versus 78 (P = .83). After lung transplantation, patients with early donor‐specific antibodies and treated with IgA‐ and IgM‐enriched immunoglobulins had 4‐year graft survival similar to patients without antibodies and showed high antibody clearance.     

Subclinical inflammation phenotypes and long‐term outcomes after pediatric kidney transplantation

The implementation of surveillance biopsies in pediatric kidney transplantation remains controversial. Surveillance biopsies detect subclinical injury prior to clinical dysfunction, which could allow for early interventions that prolong allograft survival. We conducted a single‐center retrospective cohort study of 120 consecutive pediatric kidney recipients, of whom 103 had surveillance biopsies ≤6 months posttransplant. We tested the hypothesis that subclinical inflammation (borderline or T cell–mediated rejection without clinical dysfunction) is associated with a 5‐year composite endpoint of acute rejection and allograft failure. Overall, 36% of subjects had subclinical inflammation, which was associated with increased hazard for the composite endpoint (adjusted hazard ratio 2.89 [1.27, 6.57]; P < .01). Subjects with treated vs untreated subclinical borderline rejection had a lower incidence of the composite endpoint (41% vs 67%; P < .001). Subclinical vascular injury (subclinical inflammation with Banff arteritis score > 0) had a 78% incidence of the composite endpoint vs 11% in subjects with no major surveillance abnormalities (P < .001). In summary, we showed that subclinical inflammation phenotypes were prevalent in pediatric kidney recipients without clinical dysfunction and were associated with increased acute rejection and allograft failure. Once prospectively validated, our data would support implementation of surveillance biopsies as standard of care in pediatric kidney transplantation.     

Direct‐acting antivirals are effective and safe in HCV/HIV‐coinfected liver transplant recipients who experience recurrence of hepatitis C: A prospective nationwide cohort study

Direct‐acting antivirals have proved to be highly efficacious and safe in monoinfected liver transplant (LT) recipients who experience recurrence of hepatitis C virus (HCV) infection. However, there is a lack of data on effectiveness and tolerability of these regimens in HCV/HIV‐coinfected patients who experience recurrence of HCV infection after LT. In this prospective, multicenter cohort study, the outcomes of 47 HCV/HIV‐coinfected LT patients who received DAA therapy (with or without ribavirin [RBV]) were compared with those of a matched cohort of 148 HCV‐monoinfected LT recipients who received similar treatment. Baseline characteristics were similar in both groups. HCV/HIV‐coinfected patients had a median (IQR) CD4 T‐cell count of 366 (256‐467) cells/µL. HIV‐RNA was <50 copies/mL in 96% of patients. The DAA regimens administered were SOF + LDV ± RBV (34%), SOF + SMV ± RBV (31%), SOF + DCV ± RBV (27%), SMV + DCV ± RBV (5%), and 3D (3%), with no differences between the groups. Treatment was well tolerated in both groups. Rates of SVR (negative serum HCV‐RNA at 12 weeks after the end of treatment) were high and similar for coinfected and monoinfected patients (95% and 94%, respectively; P = .239). Albeit not significant, a trend toward lower SVR rates among patients with advanced fibrosis (P = .093) and genotype 4 (P = .088) was observed. In conclusion, interferon‐free regimens with DAAs for post‐LT recurrence of HCV infection in HIV‐infected individuals were highly effective and well tolerated, with results comparable to those of HCV‐monoinfected patients.