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Background. Mesangial expansion (ME) is an understudied histologic lesion in renal allografts. The current Banff mm score is not reproducible and may miss important ME features. The study aimed to improve the quantification of ME using morphometry, assess changes over time, and determine its association with allograft loss. Methods. We studied ME in 1-y and 5-y surveillance biopsies in 835 kidney transplants performed between January 2000 and December 2013. ME was assessed using the Banff mm score by a central pathologist and by morphometry. We derived 3 different morphometric measures: (1) %MEmm (%glomeruli with ME in ≥2 lobules, like Banff mm); (2) %MEany (%glomeruli with any ME lesion); and (3) %ME area (sum of all ME areas/all glomerular tuft areas). Unadjusted and adjusted Cox models assessed the risk of death-censored allograft loss. Results. From 1- to 5-y biopsies, the mean Banff mm score increased from 0.18 to 0.34, whereas %MEmm increased from 2.5% to 13.3%. Banff mm score had modest correlations with morphometric ME measures. Moderate-severe %MEmm was present in 20.1% of 5-y biopsies, whereas only 6.6% of Banff mm scores were. In general, higher ME on both 1- and 5-y biopsies was associated with a deceased donor, older recipient age, recipient diabetes/obesity (present in >50% of severely affected biopsies), higher hemoglobin A1c at 5 y posttransplant, and recurrent kidney disease. Higher ME on 5-y biopsies was associated with delayed graft function. A higher Banff mm score at 1-y biopsy and morphometry ME measures at 5-y biopsy were associated with rejection during the first year posttransplant. Morphometric ME measures were associated with allograft loss independent of Banff scores and all clinical characteristics, including kidney function and recurrent disease. The model with %MEany had the highest c-statistic (0.872). Conclusions. Banff mm score underestimates the pervasiveness of ME in 5-y biopsies. ME is common and associated with alloimmune and nonalloimmune causes of graft loss.

Background. Surgical-site infection (SSI) is the most common early infectious complication after pancreas transplantation (PT). Although SSI has been shown to worsen outcomes, little data exist to guide optimal choices in perioperative prophylaxis. Methods. We performed a retrospective cohort study of PT recipients from 2010–2020 to examine the effect of perioperative antibiotic prophylaxis with Enterococcus coverage. Enterococcus coverage included antibiotics that would be active for penicillin-susceptible Enterococcus isolates. The primary outcome was SSI within 30 d of transplantation, and secondary outcomes were Clostridioides difficile infection (CDI) and a composite of pancreas allograft failure or death. Outcomes were analyzed by multivariable Cox regression. Results. Of 477 PT recipients, 217 (45.5%) received perioperative prophylaxis with Enterococcus coverage. Eighty-seven recipients (18.2%) developed an SSI after a median of 15 d from transplantation. In multivariable Cox regression analysis, perioperative Enterococcus prophylaxis was associated with reduced risk of SSI (hazard ratio [HR] 0.58; 95% confidence interval [CI], 0.35-0.96; P = 0.034). Anastomotic leak was also significantly associated with elevated risk of SSI (HR 13.95; 95% CI, 8.72-22.32; P

Background. Few studies have addressed immunosuppression management after allograft failure (AF). Immunosuppression withdrawal to minimize complications must be balanced with the risk of sensitization and potentially reduced retransplantation. We aimed to determine relationships between immunosuppression, death, sensitization, and retransplantation among patients with AF. Methods. We performed a single-center retrospective study of patients transplanted from October 2007 to May 2017 with AF. We collected data on demographics, immunosuppression, calculated panel reactive antibody (cPRA) levels, death, retransplantation, and dialysis. Cox regression models were used to evaluate factors associated with death and retransplantation. Results. From October 2007 to May 2017, 1354 solitary ABO-compatible transplants were performed, of which 97 failed. Ten percent of patients received a preemptive retransplant. Among those who returned to dialysis (n = 87), 35% died, 25% received another transplant, and 30% remained on dialysis. After AF, 46% of patients discontinued immunosuppression. The cPRA was unchanged if immunosuppression was maintained, but immunosuppression discontinuation was associated with increased cPRA from a median (interquartile range) of 18 (0–99) to 96 (88.5–100.0; P = 0.003). Age at failure (hazard ratio, 1.1; confidence interval, 1.0-1.1) and cardiovascular disease were associated with death (hazard ratio, 2.9; confidence interval, 1.2-7.0) in multivariate analysis. Importantly, immunosuppression maintenance was not associated with increased death or retransplantation despite the increase in cPRA that occurred when immunosuppression was discontinued. Conclusions. Kidney transplant recipients with AF have a high mortality rate after dialysis initiation. Although immunosuppression withdrawal was associated with increased cPRA, it was not associated with reduced retransplantation. Therefore, it is reasonable to discontinue immunosuppression after AF despite sensitization if retransplantation is delayed.

Background. Limited health literacy (HL) is associated with decreased kidney function and death in patients with chronic kidney disease. Less is known about the impact of HL on kidney transplant (KT) outcomes. The aim of this study was to examine the relationship between HL and KT outcomes, including rates of waitlisting, healthcare utilization, acute rejection, renal allograft function, renal allograft failure, and death. Methods. We performed a retrospective review of HL data previously collected at our center. HL was assessed in a convenience sample of consecutive, English-speaking patients age ≥18 y who were evaluated for KT at Mayo Clinic in Minnesota between June 2015 and March 2017 as part of a practice improvement feasibility project (n = 690). HL was assessed using the 4-item Brief Health Literacy Screening Tool modified for the outpatient KT evaluation process. The 4 items assess confidence completing forms, reading comprehension, and oral literacy. Results. Overall, 30.4% of patients had limited or marginal HL. Patients with limited or marginal HL were less likely than those with adequate HL to be waitlisted for KT (hazard ratio = 0.62 and 0.69, respectively), even after adjusting for age, marital status, body mass index, Charlson comorbidity index, or dialysis dependency. Patient HL was not associated with post-KT healthcare utilization, acute rejection, or renal allograft function. Patients with limited or marginal HL appeared to experience a higher risk of renal allograft failure and post-KT death, but the number of events was small, and the relationship was statistically significant only for marginal HL. Conclusions. Inadequate HL is common in KT candidates and independently associated with decreased waitlisting for KT. We observed no statistically significant relationship between HL and posttransplant outcomes in our cohort. Further efforts to improve communication in patients with inadequate HL may improve access to KT.

Background. Improving both patient and graft survival after kidney transplantation are major unmet needs. The goal of this study was to assess risk factors for specific causes of graft loss to determine to what extent patients who develop either death with a functioning graft (DWFG) or graft failure (GF) have similar baseline risk factors for graft loss. Methods. We retrospectively studied all solitary renal transplants performed between January 1, 2006, and December 31, 2018, at 3 centers and determined the specific causes of DWFG and GF. We examined outcomes in different subgroups using competing risk estimates and cause-specific Cox models. Results. Of the 5752 kidney transplants, graft loss occurred in 21.6% (1244) patients, including 12.0% (691) DWFG and 9.6% (553) GF. DWFG was most commonly due to malignancy (20.0%), infection (19.7%), cardiac disease (12.6%) with risk factors of older age and pretransplant dialysis, and diabetes as the cause of renal failure. For GF, alloimmunity (38.7%), glomerular diseases (18.6%), and tubular injury (13.9%) were the major causes. Competing risk incidence models identified diabetes and older recipients with higher rates of both DWFG and nonalloimmune GF. Conclusions. These data suggest that at baseline, 2 distinct populations can be identified who are at high risk for renal allograft loss: a younger, nondiabetic patient group who develops GF due to alloimmunity and an older, more commonly diabetic population who develops DWFG and GF due to a mixture of causes—many nonalloimmune. Individualized management is needed to improve long-term renal allograft survival in the latter group.