[Evaluation of the microplate enzyme-linked assay with isolation of glycoprotein IIb/IIIa from platelet membranes: comparison with immunofluorescent tests and monoclonal antibodies].

The enzyme test with GPIIb/IIIa has been used to detect antibodies in 500 sera from patients with thrombocytopenia and mothers of infants with thrombocytopenia. The results were compared with antibody detection in the platelet suspension immunofluorescence test (PIFT) and in the monoclonal antibody immobilization of platelet antigens (MAIPA). Platelet antibodies were detected in 125 sera (25%). In 46.2% the results were positive in all three tests. However, in 38.4% the ELISA was negative while the PIFT and MAIPA were positive. On the other hand, in 14.4% the ELISA was positive while the PIFT and/or the MAIPA were negative. The ELISA appears to be useful in the detection of anti-HPA-1a antibodies, which are the main cause of AIMN and PTP. This test, however, seems to be less useful in the detection of autoantibodies. The significance of the ELISA in the detection of platelet alloantibodies responsible for refractoriness to platelet transfusions is not clear yet and requires further investigations.