Study On Diagnostic Value Of Platelet Glycoprotein-specific Autoantibody Detection In Idiopathic Thrombocytopenic Purpura

Objective:To detect and compare the levels of platelet glycoprotein-specific autoantibody GPⅡb/Ⅲa,GPⅠb/Ⅸand PAIg in the blood of Idiopathic thrombocytopenic purpura patients,non-immune thrombocytopenia patients and healthy volunteers,evaluate the clinical significance and diagnostic value of platelet glycoprotein specific autoantibody in diagnosing ITP.Methods:We selected 60 thrombocytopenic patients and 30 healthy volunteers as control,including 30 ITP patients and 30 non-immune thrombocytopenia patients.In each person we detected their PAIgG,PAIgA,PAIgM by the means of FCM and detect GPⅡb/Ⅲa and GPⅠb/Ⅸby the technique of modified monoclonal antibody immobilization of platelet antigen assay(MAIPA).Results:The positive percentage of PAIg in ITP group was 80%.The positive percentage of PAIg in non-immune thrombocytopenia group was 63.3%.There was no significant difference between ITP group and non-immune thrombocytopenia group(x~2=2.05,p＞0.05).In ITP group the positive percentage of GPⅠb/Ⅸand GPⅡb/Ⅲa by the means of MAIPA were respectively 30%and 53.3%.Only one patient in non-immune thrombocytopenia group was positive of GPⅠb/Ⅸ,there was significant difference between two groups(x~2=7.68,p＜0.05).No one was positive in control group.The sensitivity and specificity of diagnosis by MAIPA for ITP were respectively 73.3%and 100%,Its positive predictive value(+PV) was 100%. Conclusion:The sensitivity of PAIg is very high but its specificity is low.The sensitivity of MAIPA is not high but the specificity is very high.Modified monoclonal antibody immobilization of platelet antigen assay(MAIPA) can differentiate immune thrombocytopenia and non-immune thrombocytopenia,platelet glycoprotein-specific autoantibody by MAIPA technique can be a specific index in diagnosing ITP.PAIg and MAIPA can be applicated together to strenthen the sensitivity in diagnosing ITP.