A study on the CD4 + CD25 + regulatory T cells in patients with gastrointestinal malignancies

Objectives Regulatory T cells play an active role in the maintenance of the immune system's tolerance of both foreign and self antigens. Particularly, CD4 (+) CD25 (+) regulatory T cells participate in tumor immunity. The study provided further evidence on the involvement of CD4 (+) CD25 (+) regulatory T cells in immune system impairment in patients with gastrointestinal malignancies. Methods Using flow cytometry, CD4 (+) CD25 (+) regulatory T cells were analyzed in peripheral blood from 114 patients with gastrointestinal malignancies and 15 healthy controls. Results The prevalence of the CD25 (+) subset in CD4 (+) T cells was increased in patients with colorectal carcinoma compared with healthy controls. The phenotic characteristics of the CD4 (+) CD25 (+) T cells in patient with malignancies were low expression of CD45 RA and no expression of CD69. Our results indicated that when compared with healthy control, the proportions of CD4 (+) CD25 (+) T cells in the peripheral blood of patients with colorectal, gastric, and esophageal carcinoma were significantly higher (P < 0.05) in colorectal carcinoma (22.11 +/- A 9.65%), gastric carcinoma (17.74 +/- A 4.24%), and esophageal carcinoma (24.37 +/- A 4.82)%, respectively. Further analysis on the proportion of CD4 (+) CD25 (+) T cells revealed that those patients with gastrointestinal malignancies in stages IV were higher than those of in stage I-III, though no significant difference was observed (P > 0.05). However, the proportion of CD4 (+) CD25 (+) T cells in the patients with relapse gastric carcinoma (23.32 +/- A 4.98%) was significantly higher than that of patients with primary gastric carcinoma (P < 0.01). Conclusions The increased CD4 (+) CD25 (+) T cells in patients with gastrointestinal malignancies may be related to immunosuppression and tumor progression. This suggests that elimination or reduction of CD4 (+) CD25 (+) regulatory T cells can improve effective tumor immunity for immunotherapy.