免疫性血小板减少性紫癜患者血浆协同刺激分子B7-H2和B7-H3与血小板自身抗体之间的相关性分析

Correlation of Plasma Co-stimulatory Molecules B7-H2 and B7-H3 with Platelet Auto-antibodies in Patients with Immune Thrombocytopenic Purpura

目的:探讨免疫性血小板减少性紫癜(ITP)患者血浆中的协同刺激分子B7-H2和B7-H3与血小板膜糖蛋白自身抗体水平之间是否具有相关性。方法:选取2012年6月至2013年8月期间于苏州大学附属第一医院就诊的ITP患者61例及同期健康体检者25例,通过流式免疫微球(FCIA)方法检测血浆中血小板5种糖蛋白(GPⅨ、GPⅠb、GPⅢa、GPⅡb及P选择素)的自身抗体,同时采用酶联免疫吸附(ELISA)方法检测血浆中可溶性协同刺激分子B7-H2(s B7-H2)和B7-H3(s B7-H3)水平,采用SPSS软件进行统计分析。结果:ITP患者血浆中5种血小板膜糖蛋白的自身抗体水平明显升高(P<0.01);ITP患者血浆s B7-H2水平升高(P<0.05),s B7-H3无明显变化;相关性分析显示,s B7-H3与血小板P-选择素自身抗体呈负相关(r=-0.46,P<0.05),并且s B7-H2和s B7-H3水平在P-选择素自身抗体阳性的ITP患者中降低(P<0.05);ITP患者血小板计数与s B7-H2水平之间呈负相关(r=-0.3907,P<0.01)。结论:ITP患者血浆中可溶性协同刺激分子s B7-H2升高,s B7-H3水平与P选择素自身抗体有关,提示协同刺激分子B7-H2和B7-H3可能参与了ITP自身免疫的病理机制。

Objective:To investigate whether the plasma level of platelet auto-antibodies in ITP patients is related to that of co-stimulatory molecules sB7-H2 and sB7-H3.Methods:A total of 61 ITP patients and 25 healthy controls from the First Affiliated Hospital of SoochowUniversity from June 2012 to August 2013 were enrolled in this study.The expression levels of platelet auto-antibodies against 5 glycoproteins(GPⅨ,GP I b,GP Ⅲa,GP Ⅱ b and P-selectin) in plasma were detected by flowcytometric immuno-beads array,and the expression of soluable co-stimulatory molecules sB7-H2 and sB7-H3 was measured by ELISA.Results:The plasma levels of 5 auto-antibodies against platelet membrance glycoproteins significantly increased in ITP patiens(P <0.01).Compared with healthy controls,sB7-H2 levels increased(P < 0.05),while the sB7-H3 level did not significantly change(r = 0.13,P > 0.05).However,the correlation analysis showed that sB7-H3 negatively correlated with platelet P-selectin auto-antibody(r =-0.46,P <0.05),and sB7-H2 and sB7-H3 significantly reduced in ITP patients with positive P-selectin auto-antibody(P <0.01).In ITP patients,platelet counts negatively correlated with sB7-H2(r =-0.3907,P < 0.01),but did not correlate with sB7-H3.Conclusion:Soluble costimulatory molecule sB7-H2 elevates in ITP patients,and the level of sB7-H3 is associated with auto-antibodies against P-selectin,suggesting that costimulatory molecules B7-H2 and B7-H3 may be involved in the pathogenesis of immune regulation abnormality in ITP.