Background: The present study was designed to evaluate the relationship between preoperative Toll-like receptor (TLR) expression in peripheral blood monocytes (PBMC) and the postoperative inflammatory cytokine secretion from PBMC, as well as the postoperative infectious complications in patients with gastrointestinal cancer.
Methods: Peripheral blood monocytes were isolated from 26 patients on the preoperative day and on postoperative day 1 (POD1). The monocytes were stained for CD14, TLR2, and TLR4 surface expression and stimulated ex vivo with lipopolysaccharide (LPS), after which the culture supernatant tumor necrosis factor alpha (TNFα), interleukin (IL)-1β, and interferon gamma (IFNγ) concentrations were measured in the culture supernatant. Postoperative clinical courses were monitored.
Results: There was a significant positive correlation between preoperative TLR4 expression and clinical stage in patients with gastrointestinal cancer. A significant negative correlation between preoperative TLR2 or TLR4 expression and the preoperative TNFα and IL-1β production was found. Furthermore, there was a significant negative correlation between preoperative TLR2 or TLR4 expression and postoperative inflammatory cytokine production.
Conclusions: Preoperative high expression of TLR on monocytes reduces the capacity for LPS-induced inflammatory cytokine production from monocytes. An analysis of preoperative TLR expression may therefore help to elucidate the systemic immunological response and the clinical course following gastrointestinal surgery.