直肠癌新辅助治疗后外周血调节性T细胞水平与肿瘤缓解的关系

Relationship between CD4＋CD25HighCD127low regularly T cells in the peripheral blood and tumor regression after neoadjuvant therapy in patients with rectal cancer

目的：观察直肠癌患者新辅助治疗后外周血中免疫细胞比例的变化，并探讨外周血调节性T（Treg）细胞与肿瘤缓解的关系。方法前瞻性入组2013年1—12月间山西省肿瘤医院结直肠外科接受新辅助治疗的直肠癌患者，并按照新辅助治疗后T或N分期是否降期，分为降期组和未降期组。分别检测患者新辅助治疗前后外周血中CD4＋CD25highCD127low Treg细胞、CD4＋T细胞、CD8＋T细胞、NK细胞和B细胞占淋巴细胞总数的比例，观察免疫细胞比例的变化。结果共纳入108例患者，其中降期组76例，未降期组32例。两组患者治疗前各免疫细胞比例的差异均无统计学意义（均P＞0．05）。降期组新辅助治疗后CD4＋／CD8＋T细胞比值、Treg细胞和B细胞均显著下降（均P＜0．05），但NK细胞的变化无统计学意义（P＞0．05）；未降期组新辅助治疗后CD4＋／CD8＋T细胞比值和B细胞均显著下降（均P＜0．05），但Treg细胞和NK细胞的变化无统计学意义（均P＞0．05）。新辅助治疗后，降期组Treg细胞比例较未降期组明显减少[（4．4±1．7）％比（6．2±1．9）％，P＝0．001]。结论直肠癌新辅助治疗后肿瘤降期患者外周血Treg细胞比例明显降低可作为判断肿瘤缓解的参考指标。

Objective To observe the proportion change of immune cells in the peripheral blood of patients with rectal cancer after neoadjuvant therapy and to explore the relationship between tumor regression and CD4 ＋CD25HighCD127low regularly T cells （Treg cells）. Methods Patients with rectal cancer who underwent the neoadjuvant therapy before surgery at the Shanxi Cancer Hospital Colorectal Surgery Department from January to December 2013 were prospectively enrolled. These patients were divided into down-staging group and non-down-staging group according to the change of staging in accordance with TNM classification for rectal cancer after neoadjuvant therapy. Flow cytometry was used to analyze the proportions of Treg cells, CD4＋T cells, CD8＋T cells, NK cells, B cells, and CD4＋/CD8＋ratio in the peripheral blood from these patients before and after neoadjuvant therapy. Results A total of 108 patients were enrolled, including 76 cases in the down staging group and 32 cases in the non-down-staging group. Differences of immune cells proportions between two groups before neoadjuvant therapy were not statistically significant（all P〉0.05）. In the down-staging group, the proportions of Treg cells, B cells and CD4＋/CD8＋ ratio were decreased while the proportion of NK cells did not change obviously after the neoadjuvant therapy. Interestingly, in the non-down-staging group, the proportions of B cells and CD4＋/CD8＋ ratio were decreased while the proportions of Treg cells and NK cells did not change obviously after the neoadjuvant therapy. In addition, after neoadjunvat therapy, the proportion of Treg cells in down-staging group was significantly lower than that in non-down-staging group [（4.4±1.7）% vs. （6.2±1.9）%, P=0.001]. Conclusion For patients in the down-staging group after neoadjuvant therapy, the proportion of Treg cells in peripheral blood decreases, suggesting that Treg cells may be a valuable biomarker for assessing tumor regression.