Anti-HLA-A, B, C and DR antibodies in renal transplant recipients

Anti-HLA-A, B, C and DR antibodies in 173 sera derived form renal transplant recipients were examined, using the cytotoxicity techniques standardized at the 8th International Histocompatibility Workshop. About 50% of sera obtained within 6 months of transplantation showed anti-HLA-DR antibodies. Thereafter, serum anti-DR antibodies were found in about 30% of the examined sera. However, at more than 3 years after transplantation, the reappearance of anti-DR antibodies was noted in more than 60% of the examined sera. Anti-HLA-A, B and C antibodies were not found except in the sera from recipients with irreversible rejection. The post-transplant production of anti-DR antibodies against incompatible donor HLA-DR antigens was confirmed in sera derived repeatedly from the same patients.