Racial differences in the access and outcome of living-related donor kidney transplantation.

Abstract

Kidney transplantation is the preferred form of treatment for end-stage renal disease (ESRD) and an increase in the utilization of living-related donors (LRD) is crucial to alleviating critical cadaver organ shortage. In addition to lower access, the outcomes of both LRD and cadaver renal transplantation (CAD) are poorer in African Americans (Blacks). Biologic and behavioral factors have been implicated in the causes of differential access and outcome. Data on Medicare renal transplant recipients who received a kidney transplant between 1984 and 1993 who were longitudinally followed in the United States Renal Data System (USRDS) was utilized to determine the race-specific rates of LRD. The race-specific relative benefits of LRD compared to CAD were calculated. The early allografts events known to be predictive of subsequent graft survival were studied in a special cohort of LRD recipients (HLA-identical transplants) during the initial transplant hospitalization thus effectively minimizing the influence of behavioral factors on the outcome. Risks of early allograft outcome were calculated by logistic regression technique and actuarial graft survival was determined from Cox regression models with adjustment for important pretransplant and transplant covariates. The rate of LRD is four-fold lower in African Americans compared to European Americans (Whites). Female gender is also predictive of lower access to LRD. The relative benefit of LRD over CAD is similar in Blacks and Whites. There is an excess risk of early immunologic injury (acute rejection - AR: OR = 1.64, P = 0.02) and other graft events (delayed graft function - DGF: OR = 1.58, P = 0.7) in Blacks compared to Whites. These early events were associated with significantly worse graft survival in Blacks compared to similarly affected Whites. The excess risk of having the early predictors of poor outcome in African American recipients of LRD implicate previously reported intrinsic differences in immune responsiveness and the pharmacokinetics of immunosuppressives as risk factors for racial disparity in graft survival. It is concluded that biologic factors contribute significantly to the inferior outcome of living-related donor renal transplantation in African Americans.