RED-CELLS, HLA AND PLATELET ANTIBODY-FORMATION IN PATIENTS WITH MULTIPLE TRANSFUSIONS

Totally 436 Chinese patients having received multiple transfusions of red cells and platelets on more than three occasions were screened for red cell antibodies. Twenty-six (6%) of them were positive. Anti-E, - Mi(a), and -c were the common alloantibodies. Nine patients were immun ized during the period of regular transfusions, with a newly immunized rate of 2% (9/436). Among 436 patients, 387 were screened for HLA ant ibodies by lymphocytotoxicity test (LCT). The overall positive rate wa s 35%. Most of the antibodies identified were against the high-frequen cy HLA antigens in the Chinese population. About 10% of the LCT-positi ve cases reverted to negative state during the follow-up period. After chloroquine stripping of the target platelets, mixed passive hemagglu tination assay was used to detect platelet antibodies other than HLA a ntibody. Fifty-eight of 161 cases (36%) were positive for platelet ant ibodies, but half of them disappeared within 1 month. Nineteen of the 58 patients had sepsis and 2 had jaundice. These findings suggested th at HLA and platelet antibodies are common among Chinese, though their clinical significance and the role in platelet damage are doubtful.