The impact of HLA frequency differences in races on the access to optimally HLA-matched cadaver renal transplants. The Medical Advisory Committee.

We examined the donor/recipient HLA match of 448 consecutive cadaver renal transplants to determine if donor race had an impact on the quality of HLA match that was achieved. Eighty (17.9%) kidneys from black donors and 368 (82.1%) from nonblack donors (87.8% caucasians) were distributed to the blood type compatible and crossmatch negative recipients on the basis of a local variance of the United Network for Organ Sharing (UNOS) point system. There were 278 (62%) nonblack and 170 (38%) black recipients, numbers close to those of nonblacks and blacks on the waiting list (59% and 41%, respectively). Kidneys from nonblack donors represented 86% (240/278) of transplants for nonblack and 75% (128/170) of transplants for black recipients. The best matches, i.e., zero-A,B,DR, zero-A,B, zero-B,DR, and 1-A,B,DR mismatches, for nonblack recipients were solely derived from the nonblack donors, and the few well-matched kidneys from black donors were distributed to black recipients. Black recipients with zero mismatches were few (3, 2%) compared with nonblacks (21, 8%). Kidneys received by black recipients were more likely to be poorly matched (5-6 mismatches) if coming from nonblack donors (57/128, 44%) than black donors (11/42, 26%), P = 0.035. It was also observed from HLA frequency comparisons that well-matched kidneys from nonblack donors were rarely distributed to black patients with HLA phenotypes unique to or more common in blacks who represented a sizeable portion of blacks on the waiting list. We conclude that better donor/recipient HLA matches are achieved when both donors and recipients are of the same race. Thus a larger number of black donors are needed to improve the quality of HLA matching for potential black kidney transplant recipients.