目的 探讨诱导性共刺激分子（ICOS）的表达与原因不明复发性流产（URSA）的关系。方法 采集10例诊断为难免流产的URSA患者（URSA组）和10例正常早孕妇女（正常对照组）的部分蜕膜组织和外周血，采用流式细胞术检测蜕膜组织和外周血CD3+和CD4+ T细胞中ICOS的表达；Real-Time PCR检测蜕膜组织中ICOS mRNA的表达情况。结果 URSA组蜕膜组织中ICOS+CD3+ T淋巴细胞亚群所占百分比为（0.612±0.693）%，显著高于正常对照组的（0.056±0.103）%，差异有统计学意义（P<0.001）。URSA组外周血ICOS+CD4+T淋巴细胞亚群所占百分比为（1.943±0.762）%，显著高于正常对照组的（0.221±0.127）%，差异有统计学意义（P<0.001）。URSA组蜕膜组织中ICOS mRNA的相对表达量较正常对照组显著升高[(9.875±1.464) vs (2.701±1.737)]，差异有统计学意义（P<0.05）。结论 蜕膜组织中ICOS的表达异常与URSA的发病具有密切关系。

Objective To investigate the relationship between expression of inducible co-stimulator (ICOS) and unexplained recurrent spontaneous abortion (URSA). Methods The decidual tissues and peripheral blood samples were taken from 10 patients with URSA diagnosed as inevitable abortion (URSA group) and 10 women with normal early pregnancy (normal control group), the expression of ICOS CD3+T cells and ICOS CD4+ T cells in decidual tissues and peripheral blood was detected by flow cytometry, and the expression of ICOS mRNA in decidual tissues was determined by Real-Time PCR. Results The proportion of ICOS+CD3+ T lymphocyte subsets in decidual tissues of URSA group was significantly higher than that of control group [(0.612±0.693)% vs (0.056±0.103)%, P<0.001]. The proportion of ICOS+CD4+ T lymphocyte subsets in peripheral blood of URSA group was significantly higher than that of control group [(1.943±0.762)% vs (0.221±0.127)%, P<0.001]. The relative expression of ICOS mRNA in decidual tissues of URSA group was significantly higher than that of control group [(9.875±1.464) vs (2.701±1.737),P<0.05]. Conclusion Abnormal expression of ICOS in decidual tissues is closely related to the development of URSA.