First Transplant Factors and the Influence on Kidney Retransplant Outcomes

Risk factors for adverse outcomes after first transplant have been established, but less is known about predictors of risk at the time of retransplant, including the impact of first transplant characteristics. Therefore, in this study, we aimed to examine how first transplant factors may affect subsequent transplant.

Retrospective cohort study.

We analyzed data from adult patients in the United States (Scientific Registry of Transplant Recipients) who underwent second kidney transplant (2000-2017).

First transplant characteristics (age, human leukocyte antigen match, panel-reactive antibody [PRA], first transplant graft survival time, and time from failure of first transplant).

Death-censored graft loss (DCGL) after repeat transplant.

Multivariable Cox proportional hazard models.

This study included 23,688 patients who underwent repeat transplant. DCGL risk was increased for patients with higher PRA at first transplant (adjusted HR [aHR], 1.16; 95% CI, 1.00-1.34 for PRA >80% vs <20%) and decreased for recipients aged 18-30 years at first transplant (aHR, 0.87; 95% CI 0.76-0.99 vs <18 years). Compared with preemptive retransplant, patients requiring a short duration of dialysis after the first transplant failed (<1 month) had the highest risk of DCGL (aHR, 2.36; 95% CI, 2.06-2.71). First transplant survival time was also associated with risk of DCGL (aHR, 0.56 [95% CI, 0.48-0.65] for <1 month; aHR, 0.90 [95% CI, 0.80-1.02] for 1-3 years; aHR, 0.70 [95% CI, 0.62-0.78] for 3-7 years; aHR, 0.50 [95% CI, 0.44-0.57] for >7 years [relative to survival time 1 month-1 year]). Human leukocyte antigen mismatch at first transplant was not significantly associated with DCGL at retransplant.

Potential for selection bias; patients who died before retransplant or became ineligible for repeat transplant were excluded.

First transplant PRA >80%, age 18-30 years, time between a first transplant failing and retransplant, and first transplant survival duration are significantly associated with DCGL at kidney retransplantation.