The Small RNA Repertoire of Small Extracellular Vesicles Isolated From Donor Kidney Preservation Fluid Provides a Source for Biomarker Discovery for Organ Quality and Posttransplantation Graft Function Background. Delayed graft function (DGF) after kidney transplantation is negatively associated with long-term graft function and survival. Kidney function after transplantation depends on multiple factors, both donor- and recipient-associated. Prediction of posttransplantation graft function would allow timely intervention to optimize patient care and survival. Currently, graft-based predictions can be made based on histological and molecular analyses of 0-hour biopsy samples. However, such analyses are currently not implemented, as biopsy samples represent only a very small portion of the entire graft and are not routinely analyzed in all transplantation centers. Alternatives are thus required. Methods. We analyzed whether donor organ preservation fluid contain small extracellular vesicles (sEV) and whether the RNA content of these vesicles could be used as a source for potential biomarkers for posttransplantation kidney function. Results. We provide proof of principle that sEVs are present in preservation fluid, which contain RNAs associated with donor origin. Furthermore, sEV micro RNA profiles could be associated with graft function during the first 7 days posttransplantation, but no significant correlation with DGF could be established based on the current dataset. Conclusions. Overall, the predictive potential of sEV RNA biomarkers together with relatively easy and noninvasive sample collection and analysis methods could pave the way towards universal screening of donor kidney-associated risk for DGF, optimized patient treatment, and subsequently improved short- and long-term graft function and survival.

Circulating B Cells With Memory and Antibody-Secreting Phenotypes Are Detectable in Pediatric Kidney Transplant Recipients Before the Development of Antibody-Mediated Rejection Background. Development of anti–human leukocyte antigen donor-specific antibodies (DSAs) is associated with antibody-mediated rejection (AMR) and reduced allograft survival in kidney transplant recipients. Whether changes in circulating lymphocytes anticipate DSA or AMR development is unclear. Methods. We used time-of-flight mass cytometry to analyze prospectively collected peripheral blood mononuclear cells (PBMC) from pediatric kidney transplant recipients who developed DSA (DSA-positive recipients [DSAPOS], n = 10). PBMC were obtained at 2 months posttransplant, 3 months before DSA development, and at DSA detection. PBMC collected at the same time points posttransplant from recipients who did not develop DSA (DSA-negative recipients [DSANEG], n = 11) were used as controls. Results. DSAPOS and DSANEG recipients had similar baseline characteristics and comparable frequencies of total B and T cells. Within DSAPOS recipients, there was no difference in DSA levels (mean fluorescence intensity [MFI]: 13 687 ± 4159 vs 11 375 ± 1894 in DSAPOSAMR-positive recipients (AMRPOS) vs DSAPOSAMR-negative recipients (AMRNEG), respectively; P = 0.630), C1q binding (5 DSAPOSAMRPOS [100%] vs 4 DSAPOSAMRNEG [80%]; P = 1.000), or C3d binding (3 DSAPOSAMRPOS [60%] vs 1 DSAPOSAMRNEG [20%]; P = 0.520) between patients who developed AMR and those who did not. However, DSAPOS patients who developed AMR (n = 5; 18.0 ± 3.6 mo post-DSA detection) had increased B cells with antibody-secreting (IgD−CD27+CD38+; P = 0.002) and memory (IgD-CD27+CD38−; P = 0.003) phenotypes compared with DSANEG and DSAPOSAMRNEG recipients at DSA detection. Conclusions. Despite the small sample size, our comprehensive phenotypic analyses show that circulating B cells with memory and antibody-secreting phenotypes are present at DSA onset, >1 year before biopsy-proven AMR in pediatric kidney transplant recipients.

Identification of Antibiotic Administration as a Potentially Novel Factor Associated With Tacrolimus Trough Variability in Kidney Transplant Recipients: A Preliminary Study Background. Tacrolimus trough variability is an important risk factor for kidney allograft outcomes. Recent evidence suggests that the gut microbiota is associated with tacrolimus dosing requirements and direct metabolism of tacrolimus. We hypothesize that administration of antibiotics, which are known to alter the gut microbiota, is associated with tacrolimus trough variability. Methods. We conducted a retrospective chart review of subjects who received kidney transplants at our institution from 2012 to 2013 and evaluated subjects who received antibiotics during the first month of transplantation (Abx Group, N = 60) and subjects who did not (No Abx Group, N = 200). We evaluated whether antibiotic administration in the Abx Group had increased tacrolimus trough concentrations and concentration over tacrolimus dosage (C/D) after antibiotic administration. We also evaluated tacrolimus variability as measured by standard deviation (SD) and coefficient of variation between the Abx Group and No Abx Group. Results. In the Abx Group, tacrolimus trough concentration over tacrolimus dosage (C/D) increased 7 and 15 days after antibiotic administration (P = 0.001, P = 0.07, respectively, Wilcoxon signed-rank test). From postoperative day 31–45, the variability in tacrolimus trough levels in the Abx Group as measured by SD and coefficient of variation was significantly higher than the variability in the No Abx Group (P = 0.03, P = 0.02, Wilcoxon rank sum test, respectively). Conclusions. Our identification of antibiotic administration as a potentially new risk factor for tacrolimus trough variability suggests the need to carefully follow tacrolimus trough levels after antibiotic administration.

Renal Outcomes of Liver Transplantation Recipients Receiving Standard Immunosuppression and Early Renal Sparing Immunosuppression: A Retrospective Single Center Study Background. New-onset stage 4–5 chronic kidney disease (CKD) after liver transplantation (LT) is associated with high morbidity, mortality, and economic burden. In 2010, we instituted an early renal sparing immunosuppression (RSI) protocol for LT recipients with severe renal dysfunction (pre-LT dialysis/estimated glomerular filtration rate (eGFR)<30mL/min/1.73 m2 or post-LT acute kidney injury) consisting of 2 doses of basiliximab for induction and delaying tacrolimus to post-LT day 4–7. We examined the effect of early RSI on post-LT renal outcomes. Methods. Data on all adults who had LT between January 1, 2010, and December 12, 2014 were collected. We calculated the renal risk index (RRI) score for each LT recipient (https://rri.med.umich.edu). Primary outcome was new-onset post-LT stage 4–5 CKD. Results. Of 214 LT recipients, 121 (57%) received early RSI and 93 (43%) received standard immunosuppression. Cumulative incidence of new-onset stage 4–5 CKD was higher in early RSI compared with standard immunosuppression (P = 0.03). Female sex and RRI score were the significant risk factors for development of post-LT stage CKD in the entire study cohort as well as the LT recipients with RRI ≥ sixth decile (high-risk group). Conclusions. Delaying tacrolimus initiation combined with basiliximab induction did not have a durable effect on long-term renal outcomes in high-risk LT recipients. Further studies are needed to identify the effective strategies to preserve renal function by targeting patients at high risk for CKD progression.

Staged Biliary Reconstruction After Orthotopic Liver Transplantation: A Practical Surgical Strategy for High-Acuity Adult Recipients Background. Biliary complications (BC) following orthotopic liver transplantation (OLT) is strongly associated with inferior patient outcomes and increased healthcare cost. BC in high-acuity patients can be lethal. While the utility of staged biliary reconstruction after liver transplantation (SBRALT) has been reported in adult and pediatric OLT, biliary outcome data are scarce. We sought to evaluate the clinical utility and outcomes of SBRALT in high-acuity transplant recipients. Methods. We conducted an analysis from our prospective database of 149 adult OLT between January 1, 2012, and September 30, 2017. Mean follow-up was 26 months. Variables were compared for Group I: one-stage OLT with biliary reconstruction (N = 58) versus Group II: SBRALT (N = 91). Results. Compared with Group I, patients in Group II had higher acuity of illness: median model for end-stage liver disease scores (19 vs 35 P = 0.002), requirement for pretransplant intensive care unit (29.3% vs 54.9%, P = 0.022), pretransplant renal replacement therapy (15.5% vs 48.4%), estimated blood loss (2000 vs 4750 mL, P < 0.001), and intraoperative packed red blood cells transfusion (4 vs 10 units, P < 0.001). For Group II, biliary reconstruction was performed between 1 and 6 days after OLT. Hepaticojejunostomy was performed in 8.6% (Group I) and 26.4% (Group II), P = 0.010. For Groups I and II, BC rates (8.6% vs 7.7%, P = 0.955) and 1-year graft failure-free survival rates (89.7% vs 88.2%, P = 0.845) were comparable. Conclusions. Graft failure-free survival and biliary outcomes of SBRALT in high-acuity recipients are excellent and comparable to one-stage OLT for low-risk patients. SBRALT is a practical surgical strategy in complex OLT.

Very Late Recurrence of Hepatocellular Carcinoma After Orthotopic Liver Transplantation: Presentation and Management No abstract available

Heart Transplantation From Hepatitis C–Positive Donors in the Era of Direct Acting Antiviral Therapy: A Comprehensive Literature Review Background. While heart transplantation is a highly effective treatment in patients with advanced heart failure, the number of people waiting for a transplant exceeds the number of available donors. With the advent of direct acting antivirals (DAA) for the eradication of Hepatitis C, the heart transplant donor pool has been expanded to include donors with untreated Hepatitis C. To help with the development of future protocols for Hepatitis C–positive heart transplants, we performed a review of the literature on DAA therapy in the context of heart transplantation. Methods. We searched MEDLINE, EMBASE, OVIDE JOURNAL, and GOOGLE SCHOLAR for papers published between 01.01.2011 and 01.06.2019 using key words “heart transplantation” associated with “hepatitis C.” Results. After removing duplicates, we screened 78 articles and retained 16 for primary analysis and 20 for sustained virologic response 12 weeks after completion of the DAA therapy (SVR-12). The data from 62 patients were extracted from these publications. Fifty-six (90%) patients had donor-derived hepatitis C and 6 (10%) patients were chronically infected with hepatitis C before transplantation. All living transplanted patients achieved SVR-12, defined as hepatitis C virus RNA below the limit of detection 12 weeks after treatment completion. Treatment duration ranged from 4 to 24 weeks. Clinically relevant modification to the dosing of immunosuppressive mediations during DAA therapy was documented in only 1 patient (1.6%). Six (14%) patients experienced rejection during DAA therapy. Conclusions. Despite different timings of initiation of DAA therapy across the included studies, there were no differences in sustained viral clearance. Early commencement of DAA with a potentially shorter treatment duration (<8 wk) is appealing; however, further studies are required before recommending this approach.