Margret Bock

Background BK viremia after kidney transplantation (KT) poses significant risk for BK virus‐associated nephropathy and impacts graft survival. Conventional treatment involves reduction of immunosuppression, which in turn may increase risk for rejection. To address this dilemma, use of anti‐viral therapy with immunosuppressive properties such as leflunomide is an attractive option. Methods We performed a multi‐center, retrospective chart review to report tolerability and effectiveness of leflunomide use for the eradication of BK viremia and prevention of BK virus‐associated nephropathy in pediatric KT recipients. Results Seventy patients prescribed leflunomide were included and were followed up from initiation until 1 year following leflunomide completion. BK viremia was eradicated in 64 (91.4%) patients including 8 of 11 with nephropathy (BKVN) on initial biopsy. Reduced anti‐proliferative medication (AP) dosing was not associated with increase in biopsy proven rejection (BPAR). However, complete discontinuation of AP during leflunomide therapy was associated with increase in BPAR in uni‐ and multivariate logistic regression, as was targeted reduction in calcineurin inhibitor (CNI) trough goals. One graft was lost to BKVN. There was no significant association found between time to BK eradication and leflunomide trough concentration, mycophenolate dose reduction, or steroid use (univariate logistic regression). Few leflunomide adverse drug reactions (ADR) were reported (most commonly: gastrointestinal, hematologic). Conclusion Leflunomide is a promising adjunctive treatment to immunosuppression reduction for BK virus eradication with minimal ADR. AP reduction, not discontinuation, and judicious reduction in CNI trough goals with close monitoring, is a promising strategy for treatment of BK viremia with concomitant use of leflunomide therapy.

Background Renal function is reduced in patients undergoing heart transplant due to hemodynamic compromise, cardiorenal syndrome, and nephrotoxin exposure. No current studies evaluate renal function in retransplants. Methods We reviewed all heart transplants at our center from 1995 to 2021 and matched first‐time heart transplants with retransplants, based on age at transplant, sex, and race. Estimated glomerular filtration rate (eGFR) was derived from CKiD‐U25 calculator using creatinine and measured prior to transplant, 1‐week post‐transplant, 1–3, 6, and 12 months post‐transplant, and recent follow‐up. Changes in eGFR were measured within and between patients using a piecewise linear mixed effect model with matching. Exploratory univariate analysis was performed to evaluate pre‐transplant risk factors for decreased eGFR. Results The unmatched cohort included 393 heart transplant recipients, with 47 being retransplants. Thirty‐eight patients in both groups with at least 1 year of follow‐up underwent matching. Both retransplants and first‐time transplants had an initial decline in eGFR. eGFR rebounded to baseline or above baseline at 1–3 months post‐transplant, but eGFR in retransplants remained significantly lower. At 1‐year post‐transplant, the average eGFR was 67.8 ± 4.3 mL/min/1.73 m 2 versus 104.7 ± 4.3 mL/min/1.73 m 2 ( p < .001) in the retransplants and first‐time transplants group, respectively. Conclusion This study provides data on anticipated renal trajectory following retransplantation.