Does Ethnic Mismatch Between Donor and Recipient Affect Patient and Graft Outcomes in Kidney Transplantation?

Abstract

Purpose: Differences in both pt and gt survival amongst different ethnic categories has been described across organ transplants. There has also been literature discussing racial mismatch (MM) between donor and recipient as a potential variable predicting decreased outcomes among the pediatric heart transplant population. Given the discrepancy in kidney donation across different ethnicities, we aimed to determine if there was a difference in pt and gt survival between pts who were ethnically MM with their donor versus those that were ethnically matched. Methods: The UNOS-STAR file for kidney transplants (KT) as of 2013 was queried. Retransplants, multiorgan recipients, and those transplanted before 1997 were excluded from our analysis. The pts were then organized into their provided ethnic categories and divided into an ethnically matched donor-recipient group and an ethnically MM donor-recipient group. Demographic and lab data were compared using chi-squared and Kruskal-Wallis tests. Survival data were compared using Kaplan-Meier and log-rank tests. Analysis was performed on SPSS 20.0 (Chicago, IL). Results: There were 247,123 pts identified who met criteria for inclusion. Sixty percent of the pts that were ethnically matched were male while 59.8% of ethnically MM pts were male. The average age of non-MM recipients was 46.9 years and the average age of MM recipients was 47.8 years. Non-MM recipients spent an average of 531 days on the wait list while MM recipients spent 845 days. Total cold ischemia time was 10.8 hours in the non-MM cohort while the MM group was 17.4 hours. When the two groups were compared using Kaplan Meier curves, the non-MM recipients had 1, 3, and 5 year gt survivals of 93.3%, 85.6%, and 76.7%. MM recipients had gt survivals of 90.8%, 80.7%, and 69.8% over the same time periods (< p- 0.000). Pt survival over the same time periods for non-MM recipients were 96.8%, 92.5%, and 87.1% while MM recipients were 95.6%, 90.6%, 84.8% (< p- 0.000). Conclusion: Pts with ethnically matched donors were found to have improved gt and pt survival after KT with both pt and gt survival found to be significantly different. Given the number of pts listed for KT and the overall lack of available organs, it is very difficult to implement changes to address this discrepancy. However, knowledge of a difference may influence donor selection as well as policy regarding allocation.