To discuss the imbalance of the cancer patients’ cell immune system by investigating the dynamic change of activated and suppressed immune cell standards before and after chemotherapy.

The proportions of NK/T and CD4⁺ CD25^high CD127^-Treg cells in the peripheral blood of patients with 140 different malignancies (31 colorectal, 21 gastric, 27 breast and 61 lung cancers) and 38 healthy donors were determined by flow cytometry. Then, we compared the variation of Treg and NK cells in peripheral blood samples that taken from the patients, followed after the 1st, 2nd, 3rd, 4th and 5th chemotherapy cycles.

The mean percentage of Treg cells from cancer patients’ peripheral blood was significant higher than that of healthy donors (6.95%±8.96%)、(4.25%±2.59%), P<0.05. And the mean percentage of NK cells was also significant higher than that of the healthy donors (18.56%±9.19%), (12.37%±6.24%), P<0.01. As the case number limited, during the following up chemotherapy cycles of 69 cancer patients, there were no significant variations of NK cells, CD4⁺ T cells, CD8⁺ T cells, and Treg cells in these procedures. But some tendencies would be still noticed that CD4⁺ helper T cells and CD4⁺ CD25^high CD127^- regulatory T cells decreased at first and then increased as chemotherapy progressed.

The comparison between cancer patients and healthy donors has shown that the average percentage of Treg cells in the peripheral blood is higher in the patients. And the portions of Treg cells and NK cells are a little bit higher during the chemotherapy than pretreatment.