Surgical influence on Th1/Th2 balance and monocyte surface antigen expression and its relation to infectious complications

Malignancy and operation for it cause several alterations in immune function that are considered to be concerned with the development of infectious complications. Forty-three patients who underwent curative surgery for gastrointestinal malignancies were entered into this study and were divided into two groups, those with and those without postoperative infection. Changes in the proportion of Th1/Th2 subsets in CD4(+) T cells and the expression of human leukocyte antigen (HLA)-DR and CD16a molecules on monocytes were measured by flow cytometry before and after surgery. We performed intracellular cytokine stainings to exactly detect Th1/Th2 subsets. The proportions of interferon-gamma-producing CD4(+) T (Th1) cells in the preoperative state were almost equal in the two groups, and the proportion decreased on postoperative day (POD) 1 in both groups. On POD 7, the proportion of Th1 cells recovered to the preoperative level in the noninfection group, while the suppression was further reinforced in the infection group (26.8% versus 18.3%, p < 0.005). In contrast, the proportion of interleukin-4-producing CD4(+) T (Th2) cells in the infection group (11.3%) was already suppressed in the preoperative state when compared with the noninfection group (17.3%, p < 0.005). Changes in HLA-DR and CD16a expression on monocytes were similar to the changes in the proportion of Th1 cells. These results indicate that the suppression of Th1 cell and monocyte functions during the early phase of the postoperative course was directly related to the occurrence of infectious complications and that several immunological impairments have already occurred in the preoperative state in cancer patients.