Detection of antiplatelet antibodies. The first one hundred samples studied.

Abstract

Two types of platelet alloantigens are considered: type I, which refers to platelet alloantigens shared by platelets and other cells; and type II, which comprises the platelet-specific alloantigens. The Human Platelet Alloantigens (HPA) System consists of five diallelic alloantigens and eleven low frequency antigens. According to serological antigen capture assays, immunochemical methods and studies of Molecular Genetics, the glycoproteins (GP) of platelet membrane that are most frequently associated with antibodies are GPIIb-IIIa, GPIb-IX and GPIa-IIa. It is possible to detect platelet antibodies using different laboratory methods. Our experience was restricted to a solid phase system. In this method we used the indirect technique for the screening of alloantibodies and the direct technique for the detection of autoantibodies. The procedure with chloroquine solution was performed in order to differentiate between the presence of HLA and non-HLA platelet specific antibodies. Our comments are based on results obtained in a hundred samples tested throughout a period of eleven months and we briefly review the clinical features related to the diagnosis of autoimmune and alloimmune thrombocytopenia, drug-induced thrombocytopenia and other different factors of platelet destruction. The concepts of transfusional practice applied to emergency situations, platelet refractoriness strategy and the comprehensive management of patients are approached in this work.