HLA-A INCOMPATIBILITY ASSOCIATED WITH ENHANCED LONG-TERM RENAL GRAFT-SURVIVAL IN HLA-B, DR MISMATCHED TRANSPLANTS

The effect of HLA-A matching on long-term cadaver kidney graft surviva l was analysed, on average, 6 years after transplantation in a total o f 1085 cyclosporine (CyA)-treated patients. A beneficial effect of HLA -A mismatching on graft survival was found by univariate and multivari ate analyses (P < 0.05). Enhanced graft survival was associated with H LA-A mismatching in transplants mismatched for HLA-B,DR (P = 0.03), bu t not in HLA-B,DR compatible transplants.High 6 year graft survival ra tes, 78% and 66%, were found in transplants mismatched for two or one HLA-A antigens, respectively, among patients without any acute rejecti on episode. This was significantly higher than the survival rate of 55 % found in HLA-A compatible transplants (P = 0.001). In patients who h ad suffered from acute rejection episodes, a prolonged graft survival was also associated with HLA-A mismatching in HLA-B,DR mismatched tran splants (P = 0.04).The beneficial effect on graft survival of HLA-A mi smatching was most pronounced in patients treated with high/medium dos e CyA and prednisolone (P = 0.004 overall and P = 0.0007 for HLA-B,DR mismatched transplants). In conclusion, HLA-A mismatching was associat ed with enhanced long-term renal graft survival in CyA-treated recipie nts of HLA-B,DR mismatched transplants. In clinical situations, the pr esent results might, if confirmed, contribute to the prolongation of l ong-term graft survival. The results might indicate the existence of t olerance promoting allogeneic markers within the HLA-A class I region.