The platelet factor 3 immunoinjury technique re-evaluated. Development of a rapid test for antiplatelet antibody. Detection in various clinical disorders, including immunologic drug-induced and neonatal thrombocytopenias.

A modified version of the platelet factor 3 immunoinjury technique for the detection of antiplatelet antibody is described in detail; heat-inactivated sera and frozen platelets are employed. The modification allows the results of the test to be available within 4 to 5 hours after drawing the blood sample, in contrast to the 3 days required in the original method. The technical work involved is significantly reduced. The reproducibility of the technique is improved. Results obtained with the two tests correlate well. Data accumulated in 458 cases of clinical disorders associated with antiplatelet antibody are reported. Drug-dependent antiplatelet antibody was demonstrated in 26 cases of thrombocytopenia associated with 19 different drugs. Data are also presented for 23 cases of neonatal thrombocytopenia.