Cold and warm antibodies and graft survival in kidney allograft recipients.

Serial serum samples from 35 renal allograft recipients were screened for cold and warm cytotoxic antibodies using a two-stage microlymphocytotoxicity test with three incubation temperatures. Both cold and warm antibodies were reactive at 22 degrees C. The critical temperatures which distinguished the two classes of antibodies were 15 degrees C and 37 degrees C. Cold antibodies were detected in sera from 15 patients, 10 patients had warm antibodies, and the remaining 10 had a mixture of cold and warm antibodies. All the patients were cytotoxin-positive after transplantation, although not all had preformed lymphocytotoxins. At one year 14 of the patients with cold autoantibodies had functioning grafts, but only 3 of the 10 patients with warm antibodies had kidneys functioning. This difference was statistically highly significant. There was no difference in graft survival among patients with warm antibodies and those with a mixture of cold and warm antibodies.