Impact of Multiple Kidney Retransplants on Post-Transplant Outcomes in the United States

Background. Kidney retransplantation offers a valuable treatment option for patients who experience graft failure after their initial transplant. There is an increasing number of patients undergoing multiple retransplants. However, the impact of multiple kidney retransplants on post- transplant outcomes remains unclear. This study aimed to assess the association between the number of kidney retransplants and post-transplant outcomes in kidney retransplant recipients. Methods. We used the Organ Procurement and Transplantation Network and United Network for Organ Sharing (OPTN/UNOS) database to identify kidney-only retransplant recipients in United States from 2010 through 2019. We categorized kidney retransplant recipients based on their number of kidney retransplant into one and two plus kidney retransplant groups. The association of one vs two plus kidney retransplants with death-censored graft failure and patient death was assessed using Cox proportional hazard analysis, and acute rejection using logistic regression analysis. Results. Of 17,433 kidney retransplant recipients included in this study, 15,821 (91%) and 1612 (9%) had one and two plus kidney retransplants, respectively. Patients with two plus kidney retransplants were younger, predominantly White, had higher panel reactive antibody (PRA), public insurance, and education, but had less history of diabetes mellitus and total HLA mismatch compared with patients with one kidney retransplant. After adjusting for potential confounders, having two plus kidney retransplants was significantly associated with increased risk of death-censored graft failure (hazard ratio [HR] = 1.20, 95% confidence interval [CI] = 1.021.42) and allograft rejection (odds ratio [OR] = 1.30, 95% CI = 1.09-1.54), but it was not signifi- cantly associated with patient death. Conclusions. Patients undergoing multiple kidney retransplants face a higher risk of graft failure and rejection compared with those with a single retransplant. These findings underscore the need for tailored management and monitoring strategies to improve outcomes for patients receiving multiple kidney retransplants.