The effect of zero HLA class I and II mismatching in cyclosporine-treated kidney transplant patients.

The effect of HLA matching on one-year first cadaver donor graft survival rates between best and worst matches was 6% (P less than 0.001) for A, B; 7% (P less than 0.001) for DR; 9% (P less than 0.001) for A, DR; 15% (P less than 0.001) for B, DR; and 17% (P less than 0.001) for A, B, DR. For second cadaver donor grafts, the differences were comparable. Analysis of the cyclosporine-treated patients separately yielded similar results: 5% (NS) for A, B; 7% (P less than 0.001) for DR; 13% (P less than 0.001) for A, DR; 16% (P less than 0.001) for B, DR; and 18% (P less than 0.001) for A, B, DR. The most significant effect of matching was achieved by zero mismatching B and DR antigens. The one-year graft survival for patients with zero A, B, DR mismatch was 88% with cyclosporine. Without cyclosporine, zero mismatched A, B, DR grafts survive at 84%; this difference is not statistically significant. Zero mismatching for class I and II antigens (that is, A, DR or B, DR with cyclosporine) gives one-year graft survivals of 84% and 87%, respectively. The zero mismatching HLA class I and II antigen effect is lost when even one antigen is mismatched. Transfusions improved the one-year graft survival 10% in cyclosporine-treated patients, but not in those who were not treated with cyclosporine. Seventy-one patients transfused with more than 4 units of blood, zero B, DR mismatched, and treated with cyclosporine had a 91% one-year graft survival. Recipient pool sizes for obtaining zero A, B, DR or B, DR mismatched donors are calculated. Zero A, B, DR mismatched patients can be transplanted at a 19% frequency with a 10,000 recipient pool. The success rate for zero mismatching of class I and class II antigens indicates that kidney sharing and large recipient pool sizes are a reasonable policy.