HLA-DRB1 compatibility in cadaver kidney transplantation: correlation with graft survival and function

The introduction of genomic HLA-DR typing has stimulated a re-evaluation of the role of HLA-DR compatibility on cadaver kidney transplantation. We retrospectively studied the influence of HLA-DRB1 matching on the survival of 416 patients using univariate and Cox regression analysis as well as its influence on the occurrence of rejection episodes and on creatinine level at the 3rd month in the 198 recipients for whom these data were available. The following parameters were also considered: HLA-A,B compatibility, donor and recipient age, graft number, pretransplant blood transfusions and panel reactive antibodies (PRA). Twenty-four month graft survival was 100% for transplants with zero mismatches (n=47), 87.9% for those with one mismatch (n-191) and 81.3% for those with two mismatches (n=178). In the Cox model, HLA-DRB1 matching was the most significant variable influencing graft survival (47% of χ²P=0.001), followed by HLA-A,B matching (23%, P=0.02) and donor age (19%, P=0.04). Ninety-two percent of the patients with zero mismatches experienced no rejection episodes in the first 3 posttransplant months compared with 62% and 41% of patients with one and two mismatches, respectively. Mean creatinine level (mg/dl) was 1.2, 1.4, and 1.5 in patients with zero, one, and two mismatches, respectively. Should these results be confirmed by prospective studies, HLA-DRB1 compatibility will have to be considered as an organ allocation criterion.