The Contribution of Donor Quality to Differential Graft Survival in African American and Caucasian Renal Transplant Recipients

Although a number of factors contributing to the disparity in graft survival between African American (AA) and Caucasian kidney transplant recipients have been described, the role of donor quality is less well understood. This study was undertaken to determine the impact of donor quality differences on this disparity, based on review of UNOS (United Network for Organ Sharing) data on deceased donor renal transplantation from 2000 to 2010. Donor quality was determined by the kidney donor risk index (DRI), and was compared between AA and Caucasian recipients. There were 33,405 Caucasians and 22,577 African Americans in the study, with mean DRI of 1.17 versus 1.27 (p < 0.001), respectively. In analysis 2,446 recipients of each race matched by propensity scoring (based on medical, socioeconomic and immunologic covariates), mean DRI was 1.25 for Caucasians and 1.28 (p = 0.02) for AA. The hazard ratio (HR) for graft failure associated with AA race was 1.8 (p < 0.001) on unadjusted analysis, and decreased to 1.6 (p < 0.001) after matching for DRI. These results indicate a significant disparity in quality of kidneys received by African Americans, which propensity analysis indicates is partially explained by differences in medical, immunologic and socioeconomic factors. Furthermore, this difference in donor quality partially accounts for poorer graft survival in African Americans.