The goal of this study was to evaluate whether racial differences in HLA frequency affected equitability in the allocation of kidneys, given that the allocation system is heavily weighted towards HLA matching.

The subjects for this study were the 604 cadaver renal transplant candidates at the Regional Organ Bank of Illinois (ROBI). There were 352 cadaver donors during 1986 and 1987, and most kidneys were retrieved locally. HLA phenotyping was conducted on all subjects and donors, and a computer sort was used to identify racial and HLA-matching frequencies.

The racial mix among the potential recipients was 52.1% white, 39.9% black, 6.8% Hispanic, and 1.2% Oriental. The racial mix among the donors was 81.1% white, 13.9% black, and 5.1% Hispanic.

For each of the 352 donors, a computer search was conducted to find recipients that matched on four or more antigens. Between one and eleven recipient matches were identified for each of 184 of the donors. The racial mix of selected recipients was 71.8% white, 16.2% black, and 12% Hispanic. The majority of the donors were white, and white donors were most likely to match white recipients. Among recipients matched to white donors, 72.7% were white, 14% black, and 10.7% Hispanic. For the 14 black donors, the majority of the matched recipients were black (46.4% were black, 32.1% were white, and 21.2% were Hispanic). For the nine Hispanic donors, 60% of the matched recipients were white, 13.3% were black, and 26.7% were Hispanic.

Similar findings were reported for other match categories, including the zero HLA-A, -B, -DR mismatch category and the zero HLA-A and -B mismatch category. Additionally, a comparison of HLA phenotype frequencies identified specific alleles that had a marked racial distribution and therefore correlated with matching frequencies.

The authors conclude that “using HLA matching to allocate kidneys from a predominantly Caucasian donor population favors the Caucasian recipients and places the large number of blacks at a disadvantage.” The authors argue that disregarding HLA matching would negatively affect transplant outcomes and that a solution would be to increase the number of black donors.