A UNIQUE AFRICAN HLA HAPLOTYPE MAY IDENTIFY A POPULATION AT INCREASEDRISK FOR KIDNEY GRAFT-REJECTION

We determined HLA-A, -B, and -DR allele frequencies in kidney transpla nt recipients in relation to graft survival. Most recipients and donor s were from African descent, The frequency of HLA-A30 was somewhat inc reased in recipients who rejected the graft, The frequency of HLA-B42 was significantly (P=0.002) increased in recipients who rejected the g raft. Similar results were found for the HLA-DR3 allele; however, this effect was diminished when B42-, DR3+ individuals were analyzed. We f urther investigated the effect on transplant outcome of a unique Afric an haplotype A30, B42, DR3, and of segments thereof, which have a high frequency in the local population, Log-rank analysis revealed that th e negative effect on transplant outcome was least in A30-, B42+ recipi ents (P=0.417) and most pronounced in A30+, B42+ patients (P=0.006), W e postulate that the negative effect on transplant outcome may reside in the A30, B42 segment of chromosome 6 and may be caused by a stronge r than average immunoregulatory gene.