Screening of anti-B cell antibodies in the sera of renal transplant recipients by using Daudi cell line.

In order to examine the presence of antibodies against B cells, 83 sera obtained from 55 renal transplant recipients were screened by microcytotoxicity test using Daudi cell line. Out of 83 samples, 12 were pretransplant sera, 62 were post-transplant sera and 9 were from the patients whose grafts has been removed due to rejection. For the purpose of improving the reliability of the tests, 5 different rabbit complements were selected and cytotoxicity tests with them were carried out simultaneously. Pretransplant sera without blood transfusion did not show any cytotoxicity against Daudi cells. Although 42% of post-transplant sera showed cytotoxicity against Daudi cells, cytotoxic activity of the sera showed no relation with the occurrence of rejection episodes. Three serum samples out of 5 patients whose grafts had been removed due to rejection showed strong cytotoxicity against Daudi cells and the sera of 2 other patients did not. There was no relation between the cytotoxicity against Daudi cells and antibodies against Epstein-Barr virus capsid antigen in the post-transplant sera.