Significance of specific autoantibodies against platelet glycoprotein in Idiopathic thrombocytopenic purpura

Objecfive To detect the specific autoantibodies against platelet in idiopathic thrombocytopenic purpura (ITP) and to study the relationship between these autoantibodies and the severity of ITP as well as therapeutic effect.Methods Autoantibodies (GPⅡbⅢa and GPIb) against platelet glycoprotein was measured by a monoclonal antibody immobilization of platelet antigen assay (MAIPA) in 40 ITP patients.Results 10 patients had mono-specific antibodies to GP Ⅱ bⅢa and 6 patients had mono-specific antibodies to GPIbα.Another 20 patients had antibodies to both antigens and 4 patients had no detectable antibody to either platelet antigen.There Was negative correlation between the antibody against GPⅡbⅢa(b=-0.071,P<0.01),CPIbα(b=0.092,P<0.01) and platelet counts.The ratio of refractory cases in patients with antibodies to both antigens(8/20) was significantly higher than that in patients with mono-specific antibodies(1/16)(χ2=6.09,P<0.05).Conclusion The specific autoantibadies against platelet might be valuable for discrininafion of idiopathic thrombocytopenic purpura and non immune thrombocytopenia.The types of antibodies are related with severity of ITP and therapeutic effect. Key words: Thrombocytopenic purpura;  Antibody; Platelet glycoprotein