OBJECTIVETo evaluate the CD4+CD25+ regulatory T cells (Treg) and other lymphocyte subsets in the peripheral blood of patients with advanced lung adenocarcinoma.

METHODSPeripheral blood samples were obtained from 64 patients with advanced lung adenocarcinoma (case group) and analyzed by flow cytometry. The ratios of CD4+CD25+Treg T cells and other T lymphocyte subsets in peripheral blood were compared with those from 33 healthy controls (control group).

RESULTSThe percentages of CD3+ and CD3+CD4+ were (66.5±11.0)% and (37.7±10.6)% respectively in the peripheral blood of the case group, which were significantly lower than those [(72.0±6.0)% and (42.0±6.4)%] in the control group (t=-3.2,-2.4; P=0.020, 0.015, respectively). The ratio of CD4+ CD25+ Treg cells in case group (10.5±4.0)% was significantly higher than that [(8.4±3.5)%] in the control group (t=-2.2, P=0.013). CD4+/CD8+ value of case group (1.4±0.8) was significantly lower than that (1.8±0.7) in control group(t=-2.2, P=0.029). CD3+CD8+, CD8+CD28-, and CD8+CD28+ showed no significant differences (all P>0.05). Smoking, differentiation grade, and size of the tumor showed no association with the function damage of T lymphocyte subsets, while the carcino-embryonic antigen level did.

CONCLUSIONSIn patients with advanced lung adenocarcinoma, Treg increases and CD4+/CD8+ decreases, suggesting remarkably suppressed immune functions. However, more research is warranted to validate the association of T cells subset dysfunction with smoking, differentiation grade, and size of tumor.