流式细胞术检测血小板相关抗体诊断原发免疫性血小板减少症的价值

Clinical Significance of Detecting Platelet-Associated Immunoglobulin by Flow Cytometry for Diagnosis of Primary Immune Thrombocytopenia

目的探讨流式细胞术(FCM)检测血小板相关抗体(PAIg)在诊断原发免疫性血小板减少症(ITP)的价值。方法 ITP初诊患者50例、继发免疫性血小板减少(sITP)患者92例和健康对照组31例,应用FCM检测PAIgG、PAIgA及PAIgM的表达水平,通过受试者工作特征(ROC)曲线分析确定最佳诊断界值。结果 ITP患者初诊时PAIgG、PAIgM及PAIgA抗体表达水平,均高于sITP组和正常对照组(P<0.01);sITP组PAIgM和PAIgA表达水平明显高于正常对照组(P<0.05),PAIgG差异无统计学意义(P>0.05)。PAIgG、PAIgM和PAIgA对ITP的最佳诊断界值分别为5%、7%和4%,PAIgM异常增高对诊断ITP的敏感性和特异性分别为72.0%和73.2%,均高于PAIgG(60.0%、67.5%),PAIgA的特异性最高(88.6%),但敏感性最低(48.0%);PAIgG联合PAIgM检测敏感性(78.0%)高于二者单独检测,特异性(66.7%)低于单独检测。结论检测PAIg对ITP的鉴别诊断具有重要的临床意义,PAIgG联合PAIgM的诊断价值优于二者单独检测。

Objective To investigate the clinical significance of platelet-associated immunoglobulin（PAIg） detected by flow cytometry（FCM） in the diagnosis of primary idiopathic thrombocytopenia（ITP）.Methods The expressing level of PAIg （PAIgG,PAIgM,PAIgA） was detected by FCM in 50 newly diagnosed patients with primary ITP,92 patients with secondary immune thrombocytopenia（sITP） and 31 healthy controls.Receiver operating characteristic （ROC） curve analysis was used to determine the optimal cutoff value .Results The expressing levels of PAIgG ,PAIgM and PAIgA in newly diagnosed ITP patients were significantly higher than those in sITP group and health controls （P〈0.01）.The expressing levels of PAIgM and PAIgA in sITP group were significantly higher than health controls （P〈0.05）,but there was no significant difference in PAIgG（P〉0.05）.The optimal cutoff values of positivity of PAIgG,PAIgM and PAIgA for the discrimination of ITP and non-ITP were 5%,7%and 4%,respectively ,and the sensitivity and specificity of a positive PAIgM individual test for ITP were 72.0%and 73.2%,respectively,which were higher than those of PAIgG （60.0%,67.5%）.There were the highest specificity（88.6%） and the lowest sensitivity（48.0%） in PAIgA.The sensitivity of PAIgG plus PAIgM test was 78.0%, higher than that of PAIgM or PAIgG test alone .The specificity of PAIgM plus PAIgG test was 66.7%,lower than that of PAIgM or PAIgG test alone .Conclusion PAIg detection is valuable in differential diagnosis of ITP .The diagnostic value of PAIgM combined with PAIgG is better than that of PAIgM or PAIgG alone .