[Thrombocyte transfusion: increase in platelets in relation to clinical and immunologic prerequisites].

We determined in 35 patients with severe thrombocytopenia (AML n = 10; ALL n = 4; CML = 1; idiopathic myelofibrosis n = 1, aplastic anemia n = 1; undergoing bone-marrow transplantation n = 17) factors influencing the corrected count increment (CCI) after platelet transfusions. Out of 195 transfusions 86 (44%) failed to increased platelet counts (CCI less than 5 X 10(9) platelets/l). A significant percentage of transfusion failures occurred in patients with splenomegaly and/or fever (54% vs. 29%; p less than 0.002). Antibodies directed against donor platelets were found only twice. No correlation between reactivities demonstrable by the lymphocytotoxic test (n = 144) or the radioimmune antiglobulin test (n = 67) and the CCI was obvious. HLA antigen identity was also not predictive. Thus, transfusion failures in patients with low alloimmunization will not be predicted by in vitro antibody screenings. The patients' clinical condition has the most important influence on posttransfusion increment.