[Substitution ofpolysensitized patients with platelets from HL-A typed single donors]

80 platelet transfusions from 38 different "full-house" HLA-typed single donors (10 siblings, 28 unrelated persons) were given to 14 thrombocytopenic patients refractory to platelets from random donors. The transfusions resulted in increased platelet increments, provided that the donor had no additional HLA-specificities whatsoever. In 14 out of 19 situations of not-identity between donor and recipient and with poor posttransfusion platelet increments, lymphocytotoxicity tests (incubation of 180 min at room temperature) were positive. This test therefore appears to be a useful tool in predicting the outcome of the transfusions. Granulocytotoxicity tests were positive in 4 HLA-identical donor-recipient pairs. Although severe transfusion reactions were observed, no detrimental influence on platelet increments could be found.