Suppression of interleukin-6 to interleukin-10 ratio in chronic alcoholics: association with postoperative infections

Abstract.

Objective: To investigate the interleukin-6 (IL-6) to interleukin-10 (IL-10) ratio and levels of sE-selectin in patients undergoing elective surgery of the upper digestive tract and to define the differences in the perioperative immune response between chronic alcoholic and non-alcoholic patients. Design: Prospective pilot study. Setting: Single center, interdisciplinary intensive care unit (ICU) at a university hospital. Measurement and main results: The study compared chronic alcoholics (n=25) and non-alcoholics (n=20) before and after surgery for resection of upper digestive tract tumors. White blood cell counts, C-reactive protein and circulating levels of sE-selectin, the pro-inflammatory cytokine IL-6 and the inhibitory cytokine IL-10, were obtained at hospital admission, preoperatively, postoperatively at ICU admission and 2 and 4 days later. Rates of postoperative infectious complications including pneumonia and sepsis were determined. sE-selectin only differed between chronic alcoholics and non-alcoholics preoperatively. Compared to non-alcoholics, chronic alcoholic patients showed a fourfold increase in circulating levels of IL-10 (p<0.01) and a suppression of the IL-6/IL-10 ratio (p=0.001) immediately after surgery. Coincident with the immune alterations, chronic alcoholics had a prolonged ICU stay (p<0.01) and a threefold increased rate of wound infections (p<0.05) and pneumonia (p<0.01). Lower IL-6/IL-10 ratios were associated with increased rates of infectious complications (p<0.05). Conclusion: Chronic alcoholics had decreased IL-6/IL-10 ratios at ICU admission and increased rates of infectious complications in the postoperative ICU course. This may indicate immediate postoperative immune suppression before the onset of infections and may help to identify chronic alcoholic patients at risk.