Sensitization after transplantation

1. Out of 122 sera from patients who had rejected a kidney transplant, 82% had cytotoxic antibodies to HLA. These antibodies were present in about equal frequency regardless of when the graft was rejected. Twelve patients who had rejected their grafts after 5-15 years also produced clear HLA antibodies. 2. The HLA antibodies were not directed to all the mismatches of the donor, but rather appeared to be against a few of the specificities. Thus the graft could have been rejected by a response directed at a few major determinants. Antibodies to some antigens were not detected at all. 3. Some patients produced their HLA antibodies many months after the rejection of their first graft.