Serum monocyte chemoattractant protein-1 in patients with postoperative infectious complications from gastrointestinal surgery for cancer.

We examined the kinetics of serum monocyte chemoattractant protein-1 (MCP-1) perioperatively and clarified its significance regarding the development of infectious complications. We studied 94 patients who underwent gastrointestinal surgery for gastric or colorectal cancer at Mie University Hospital from 1996 to 2000. Serum concentrations of MCP-1 and interleukin-6 (IL-6) were measured perioperatively. The number of circulating lymphocytes and neutrophils were counted to assess the apoptotic rate of neutrophils. Patients were divided into two groups at the median preoperative MCP-1 level obtained from 40 gender- and age-matched healthy volunteers. The rate of developing infectious complications was significantly higher and tumor size was significantly larger in the low MCP-1 group than in the high MCP-1 group. The increasing IL-6 ratio (postoperative/preoperative IL-6 level) in the low MCP-1 group was about twofold greater than that in the high MCP-1 group. The neutrophil level calculated for the low MCP-1 group was significantly higher than that in the high MCP-1 group on postoperative day 3. We concluded that a decreased level of serum MCP-1 reflected tumor-related immunosuppression. Low MCP-1 levels were associated with an exaggerated postoperative IL-6 response and delayed neutrophil apoptosis, which affected the incidence of postoperative infectious complications developing in patients with gastrointestinal malignancies.