特发性血小板减少性紫癜自身抗体的特异性免疫诊断

The Special Immune Diagnosis of Autoantibody in Idiopathic Thrombocytopenic Purpura

目的 检测特发性血小板减少性紫癜(ITP)及非免疫性血小板减少症的抗血小板特异性抗体及PAIgG,并比较其诊断及鉴别诊断的价值。方法 用酶联免疫吸咐竞争法检测PAIgG,用血小板抗原单克隆抗体固相化法(MAIPA)和改良抗原捕获ELISA法(MACE)检测抗血小板膜糖蛋白(GPⅡ b／Ⅲa、GPⅠ b／Ⅸ和P-选择素)的特异性抗体。结果 PAIgG在ITP组的阳性率为94.0％,非免疫性血小板减少症组为53.3％。MAPIA和MACE在ITP组的阳性率分别为GPⅡb／Ⅲa 31.3％、26.7％,GP Ⅰ b／Ⅸ12.0％、8.7％,P-选择素24.6％、19.3％,在非免疫性血小板减少症组中MAIPA和MACE的阳性率除1例P-选择素阳性外,其余均为阴性,与ITP组相比,P<0.001。结论 PAIgG的敏感性可达90％以上,但特异性较差;而MAIPA和MACE虽然敏感性较低,但具有很高的特异性,并能鉴别免疫性血小板减少和非免疫性血小板减少。抗血小板特异性抗体的检测可成为ITP的特异性诊断指标。

Objective To measure antiplatelet antibodies and platelet-associated IgG (PAIgG) of patients with idiopathic thrombocytopenic purpura (ITP) or non-immune thrombocytopenia and compare its significance in diagnosis and differentiating diagnosis. Methods PAIgG was measured by using ELISA. Antibodies of and membrane protein of platelet (GPⅡb/Ⅲa, GPⅠb/Ⅸ, P-Selection) were measured by using MAIPA and MACE. Results The positive percentage of PAIgG in ITP was 94.0% and in non-immune thrombocytopenia was 53.3% . The positive percentage of GPⅡ b/Ⅲa in ITP by MAPIA and MACE was 31. 3 % and 26.7 %, GPIb/Ⅸ was 12. 0 % and 8.7 %, P-Selection was 24.6 % and 19.3%. GPⅡb/Ⅲ a、GPIb/Ⅸ and P-Selection in non-immune thrombocytopenia by MAPIA and MACE were negative but one patient being P-Selection positive, P<0.001 in comparison with ITP. Conclusion The sensitivity of PAIgG is over 90 %, but the speciality is bad. The speciality of MAIPA and MACE is very high although low sensitivity in comparison with PAIgG. The measurement of antiplatelet special antibodies by using MAIPA and MACE can differentiate immune thrombocytopenia or non-immune thrombocytopenia. It may be suitable to clinical diagnostic application to ITP.