RELEVANCE OF DONOR-SPECIFIC ANTI-HLA ANTIBODIES FOLLOWING RENAL TRANSPLANTATION
Patrick Supon(1), Don Constantino(2), Ping Hao(3), Linda Cagle(1), Amy Hahn(2), David J. Conti(4) and Brian M. Freed(1) 1)Clinical Immunology, UCHSC, Denver 2)Transplant Immunology, 4)Surgery, Albany Medical College, NY 3)Kunming Medical College, P.R. China

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While IgG antibodies to HLA class I and II antigens in pretransplant sera are generally considered a contraindication to renal transplantation, very little is known regarding the effects of HLA antibodies that develop months or years after the transplant. The purpose of this study was to retrospectively analyze 415 sera from 263 renal allograft recipients who were readmitted to hospital for any reason between 1989 and 1998 in order to determine if a correlation existed between the appearance of donor-specific anti-HLA antibodies and graft rejection.

Sera were assayed for IgG HLA class I and II antibodies by ELISA. The ELISA results were analyzed using contingency tables with Fisher's exact test and compared to mismatched antigens in the donor.

Antibodies to donor HLA class I molecules in the posttransplant sera were extremely rare, occurring in only 6 of the 415 sera analyzed. Antibodies to donor class II antigens were slightly more common, occurring in 25 of the 415 sera (6%). In 19 of the 25 cases, the presence of donor-specific HLA class II antibodies was associated with episodes of either acute (n=12) or chronic rejection (n=7). Five patients had antibodies to both class I and class II donor antigens, and all five of them lost their grafts to rejection. However, 90% of all acute rejection episodes and 83% of all chronic rejections were not associated with donor-specific HLA antibodies, and 77% of all acute and chronic rejections occurred in patients without any HLA antibodies.