Does Impaired Th1/Th2 Balance Cause Postoperative Infectious Complications in Colorectal Cancer Surgery?

Background

Recent studies have shown that the Th1/Th2 balance shifts toward Th2 dominance in cancer-bearing state or under surgical stress. This study was designed to investigate whether perioperative impaired Th1/Th2 balance is associated with the occurrence of postoperative infection following colorectal cancer surgery.

Methods

From 53 patients with colorectal cancer, peripheral blood samples were collected, before surgery, and on the 3rd, 7th, and 14th postoperative days. The proportions of CD4⁺ T-helper cells producing intracellular cytokines including interferon-γ (Th1 cells) and interleukin-4 (Th2 cells) were measured by flow cytometry. The patients were divided into two groups according to the presence (infected group) and absence (noninfected group) of postoperative infection.

Results

The infected group showed serum hypoalbuminemia and higher frequency of blood transfusion compared with the noninfected group. No significant difference in the proportion of Th1 cells was observed between the two groups. In contrast, the infected group showed significantly higher proportions of Th2 cells than the noninfected group (1.9 ± 0.9% for noninfected group and 2.8 ± 1.3% for infected group; P < 0.05). Regarding Th1/Th2 ratio, the infected group showed a lower ratio than the noninfected group (14.7 ± 8.8 for noninfected group and 9.0 ± 3.2 for infected group; P < 0.05). Throughout the postoperative period, the Th1/Th2 ratio in the infected group was significantly lower than that in the noninfected group.

Conclusions

This study demonstrated that perioperative Th2 dominance in addition to hypoalbuminemia and blood transfusion is associated with the occurrence of infection following colorectal cancer surgery. These results provide further information that may direct future treatments based on the Th1/Th2 concept focusing on decreasing the risk of postoperative infection.

Key Words: postoperative infection, colorectal cancer, Th1/Th2 balance, surgical stress