目的：检测CD4+CD25+CD127low/-调节性T细胞（regulatory T cell，Treg）在甲状腺乳头状癌（papillary thyroid carcinoma，PTC）患者外周血的比例，探讨其临床意义。方法：选择2010年8月至2011年2月在上海交通大学医学院附属仁济医院进行手术治疗的PTC患者40例及甲状腺腺瘤患者30例，以CD4+CD25+CD127low/-为标志，采用流式细胞术检测PTC患者及甲状腺腺瘤患者外周血中CD4+CD25+CD127low/- Treg的比例，分析其与PTC临床病理特征的关系。结果：与甲状腺腺瘤患者比较，PTC患者外周血中CD4+CD25+CD127low/- Treg比例明显升高\[（7.836±1.668）% vs（5.365±1.156）%，P<0.05\]；外周血CD4+CD25+CD127low/- Treg比例与PTC临床分期、颈部淋巴结转移相关（均P<0.05），与年龄、性别及肿瘤大小无关（P>0.05）。结论：PTC患者外周血CD4+CD25+CD127low/- Treg比例显著增加，且与PTC临床分期、颈部淋巴结转移相关。

Objective:To evaluate the propotion of CD4+CD25+CD127low/- regulatory T cells in peripheral blood of papillary thyroid carcinoma (PTC) patients and its clinical significance. Methods: Forty patients with PTC and 30 patients with thyroid adenoma were included in this study. They were all treated in Renji Hospital, Medical School of Shanghai Jiaotong University between August 2010 to February 2011. The proportion of CD4+CD25+CD127low/-Treg in peripheral blood of PTC and thyroid adenoma patients was evaluated by flow cytometry, and their relationship to clinicopathological features of PTC was studied. Results: Compared to thyroid adenoma patients, the proportion of CD4+CD25+CD127low/-Treg in peripheral blood of PTC patients was significantly increased (\[7.836±1.668\]% vs \[5.365±1.156\]%, P<005). The proportion of CD4+CD25+CD127low/-Treg was related to clinical tumor stage and cervical lymph node metastasis of PTC patients (all P<0.05), but not related to age, gender, and tumor size (P>0.05). Conclusion: The proportion of CD4+CD25+CD127low/-Treg in peripheral blood of PTC patients was significantly increased, and related to clinical tumor stage and cervical lymph node metastasis of PTC patients.