Objective: To evaluate the clinical significance of platelet glycoprotein-specific autoantibody detection and platelet-associated IgG (PAIgG) measurement in the differential diagnosis between autoimmune thrombocytopenia and nonimmune thrombocytopenias.
Methods: Anti- GP II b/III a and anti-GP I b/IX autoantibodies were detected by a modified monoclonal antibody immobilization of platelet antigens assay (modified MAIPA), and PAIgG by competitive ELISA.
Results: Comparing with the measurement of PAIgG, the GP-specific autoantibody assay was less sensitive but much more specific for the diagnosis of autoimmune thrombocytopenia.
Conclusion: The platelet GP-specific autoantibody detection is considerably better than PAIgG measurement in discriminating immune from nonimmune thrombocytopenia.