The importance of class I and class II HLA in cadaveric renal transplantation.

The importance of avoiding mismatches (MM) at Class I and Class II HLA antigens in cyclosporine-treated renal allograft patients is controversial. In order to assess the role of HLA, 200 consecutive cadaveric renal allografts over a 4-year period were analysed. All patients received cyclosporine/predinisone immunosuppression and 75% were induced with ALG. Minimum follow-up period was one year. HLA A, B, DR, DQ, and DRw52/53 typing were available on 77-100% of allografts. A beneficial effect was noted at the HLA A locus. One-year survival was 87.2% in the 0 and 1 HLA A MM group combined vs 73.8% in the 2 HLA A MM group (p less than 0.05). The mean creatinine level at one year was also lower in the 0 plus 1 MM vs 2 MM group: 152.8 mumol/L vs 184.8 mumol/L, respectively (p less than 0.05). Significantly fewer rejection episodes occurred in the 0 and 1 HLA DQ MM group combined vs the 2 MM group. Steroid-resistant rejection episodes (SRRE) were not associated with the number of HLA MM. Patients who had an SRRE had significantly higher mean current and historical peak panel reactive antibodies (PRA) than patients who did not have SRRE. These results indicate that avoiding mismatches at the HLA A locus may improve renal allograft survival, and matching at HLA DQ may predispose patients to a more quiescent post-transplant course. The degree of preoperative sensitization may be an important etiologic factor in SRRE.