Detection of platelet-associated immunoglobulin in immune thrombocytopenia by flow cytometry.

The development of a flow-cytometry (FCM) technique for the direct detection of antiplatelet globulins bound to the surface of platelets (platelet-associated immunoglobulins, or PAIg) is described and utilized to evaluate patients with idiopathic thrombocytopenic purpura (ITP). Elevated levels of platelet-bound globulin were detected by FCM in the ITP patients studied. When plasma was analyzed by FCM for the presence of antiplatelet antibodies, only one patient demonstrated elevated levels. The use of FCM in the direct analysis of PAIg may result in earlier diagnosis and better management of immune thrombocytopenias.