血小板相关IgG(PAIgG)常用于ITP与其它免疫性血小板减少的诊断.本研究用流式细胞仪(FCM)检测了47例ITP(包括Evans综合症)、13例非免疫性血小板减少、10例无血小板减少的自身免疫性溶血性贫血(AIHA)和31例正常人的PAIgG,并与ELISA测定的结果进行比较.FCM检测的ITP患者PAIgG的荧光强度(MFI)(2.26±2.29)明显高于非免疫性血小板减少(0.33±0.39),AIHA(0.17±0.07)和正常对照组(0.25±0.15)(P值均小于0.01).同时,ITP患者PAIgG阳性血小板百分率[(44.1±29.0)%]也明显高于非免疫性血小板减少[(17.5±9.4)%],AIHA[(10.7±7.5)%]和正常对照[(16.6±8.4)%](P值均小于0.01).有13例ITP患者(23.4%)的血小板荧光峰形有异常(双峰或峰拖尾),其中有7例只出现峰形异常而无MFI或阳性血小板百分率的改变.这种情况在正常人的血小板未观察到,这可能反映出不同的血小板群体有诊断价值.用FCM测定ITP患者PAIgG总的阳性率为87.2%,稍高于用ELISA检测的83.0%阳性率,但两者之间无显著性差异.两种检测结果的符合率为85.1%.本研究表明,FCM是一个快速与敏感的测定PAIgG的方法,可成为检测免疫性血小板减少的常规的新方法.%Measurement of platelet -associated imunoglobulin (Palg)has frequently been applied for the diagnosis of idiopathic thrombocytopenic purpura(ITP)and other immune thrombocytopenias .In the present study, a flow cytometry (FCM)analysis has been used to detect and characterize Palg in 47 patients with ITP and Evans'syndrome,13patients with non-immune thrombocytopenia,10 patients with autoimmune hemolytic anemia (AIHA) whose pltelet counts were in normal range, and 31 healthy volunteers. Withs FCM measurement, mean fluorescence intensity(MFI)of platelets from patients with ITP and Evans'syndrome (2.26±2.29)was significantly higher than those from non immune thrombocytopenia (0.33±0.39),AIHA(0.17±0.07) and control subjects (0.25±0.15)(P＜0.01).Meanwhile ,the percentage of positive platelets of patients with ITP and Evan' s syndrome [(44.1±29.0)%] was also higher than those of non-immmune thrombocy topenia [(17.5±9.4)%],AIHA [(10.7±7.5)%] and control subjects [(16.6±8.4)%] (P＜0.01).In addition, some peak shape abnormality (double peaks and peak tail) in the histogram of fluorescence intensity (log) of 11 patients (23.4%) with ITP and Evans' syndrome either alone of accompanied with quantitative alteration of MFI and /or positive platelet percentage. In seven cases, the peak shape abnormality was the unique characteristic that could be detected and have never been seen in normal platelets. This phenotypic alteration perhaps reflects the existence of different platelet populations and could be of diagnostic value. Totally, the positive result of FCM measurement in patients with ITP and Evans' syndrome was 87.2% ,slightly higher than 83.0% positive rate with ELISA method, without statistical difference. The correspondent rate of the results of these two analytical settings was 85.1%.This study shows that FCM assay is a rapid and sensitive method for the measurement of Palg and seems to be suitable as a novel routine diagnostic technique of immune thrombocytopenia.
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