自身免疫性血小板减少性紫癜相关抗体的研究

目的　探索对自身免疫性血小板减少性紫癜 (AITP)诊断特异和敏感的实验方法。方法　采用单克隆抗体特异性俘获血小板抗原技术 (MAIPA技术 )并加以改进 ,对比检测血小板洗脱液和血浆中血小板膜糖蛋白特异性抗体。结果　AITP患者血浆游离抗血小板膜糖蛋白 (GPⅡb Ⅲa、GPⅠb Ⅸ )抗体总阳性率为 38.89%(5 4例中 2 1例 ) ,洗脱血小板表面抗血小板膜糖蛋白 (GPⅡb Ⅲa、GPⅠb Ⅸ )抗体总阳性率为 6 8.5 2 %(5 4例中 37例 ) ,两者差异有显著性 (校正 χ2 =19.39,P <0 .0 0 5 )。原发AITP组血浆游离及洗脱血小板表面抗血小板糖蛋白 (GPⅡb Ⅲa、GPⅠb Ⅸ )特异性抗体总阳性率与继发性AITP组比较差异无显著性。AITP患者血小板数量与自身抗体滴度呈明显负相关。结论　MAIPA法检测血小板洗脱液中抗血小板糖蛋白抗体在AITP的诊断和治疗中具有高度特异性 ,且敏感性较血浆抗体检测显著提高。

Study on autoimmune thrombocytopenic purpura related antibody

OBJECTIVE: To investigate a specific and sensitive assay for the diagnosis of autoimmune thrombocytopenic purpura (AITP). METHODS: Glycoprotein specific autoantibodies in platelet eluate and plasma were detected by a modified monoclonal antibody immobilization of platelet antigens assay (MAIPA). RESULTS: The overall positive rate of specific autoantibodies against platelet GPIIb/IIIa and GPIb/IX in plasma was 38.89% and in eluated platelet membrane was 68.52%. The difference between them was significant (corrected chi(2) = 19.39, P < 0.005). The proportion of positive MAIPA results between primary AITP and secondary AITP was not significantly different. There was a significant inverse correlation between antibody level and platelet count. CONCLUSION: Detection of eluated GP-specific autoantibodies by MAIPA is highly specific and much more sensitive as compared with the measurement of their plasma counterparts in the diagnosing and therapeutic monitoring of AITP.