直接MAIPA对免疫性和非免疫性血小板减少性紫癜的鉴别诊断

目的检测免疫性与非免疫性血小板减少患者血小板膜糖蛋白特异性自身抗体，评价该方法在免疫性和非免疫性血小板减少性紫癜鉴别诊断中的价值。方法应用改良直接单克隆抗体俘获血小板抗原技术(MAIPA)检测血小板膜糖蛋白(GPⅡh／Ⅲa、GP I b和GPI a／Ⅱa)特异性自身抗体。结果免疫性血小板减少患者自身抗体阳性率(76．4％)显著高于非免疫性血小板减少患者(3．6％)(P＜0．05)。直接MAIPA诊断免疫性血小板减少的敏感性为76．4％，特异性为96．4％，阳性预测值为97．1％。GPⅡh／Ⅲa特异性自身抗体阳性的免疫性血小板减少患者血小板计数与自身抗体吸光度比值呈显著负相关(r=-0．338，P＜0．05)。结论直接MAIPA检测血小板膜糖蛋白特异性自身抗体对于鉴别免疫性与非免疫性血小板减少有一定意义。

Study on the direct MAIPA technique in the differential diagnosis of immune and non-immune thrombocytopenia

OBJECTIVE: To evaluate the clinical usefulness of direct monoclonal antibody immobilization of platelet antigen (MAIPA) technique in the differential diagnosis of immune and non-immune thrombocytopenia. METHODS: Platelet-bound autoantibodies in thrombocytopenic patients (immune and non-immune) were measured by direct MAIPA. Monoclonal antibodies against GP II b/III a, GPIb and GP I a/II a were used. RESULTS: The positive rates of platelet-bound GP-specific autoantibodies between immune (76.4%) and non-immune thrombocytopenia (3.6%) were significantly different (P < 0.05). The direct MAIPA had a sensitivity of 76.4%, a specificity of 96.4%, and a positive predictive value of 97.1% for the diagnosis of immune thrombocytopenia. There was a significant inverse correlation between platelet-bound GP II b/III a specific autoantibody levels and platelet counts (r = -0.338, P < 0.05). CONCLUSION: The direct MAIPA technique can be used to differentiate immune from non-immune thrombocytopenias.