Study of effect of surgical stress on immunity in patients with gastrointestinal cancer.

We investigated the effect of surgical stress on immunity in patients with gastrointestinal cancer by three color flow cytometry centering on lymphocyte subsets. The control group consisted of patients with cholelithiasis as a benign disease and the cancer groups consisted of patients with gastric cancer and those with colorectal cancer. Total lymphocyte in peripheral blood, lymphocyte subsets by monoclonal antibody and NK cell activity were measured before and after operation in the target patients. The cell ratio of CD4+CD45R+Leu8+ (suppressor inducer T), CD8+CD11b+ (suppressor T) were significantly higher in the gastrointestinal cancer group when lymphocyte subsets were investigated after operation. Further, the cell ratio of CD3+CD16-CD56+ (T-LAK) was significantly lower. These findings suggest that decrease in immunity as a result of surgical stress is greater in patients with gastrointestinal cancer than in those with a benign disease.