Hypothesis: Compartmentalization of cytokines in intraabdominal infection

Background. Although the proximal role of systemic cytokines in the infectious-inflammatory cascades is well recognized, the magnitude and meaning of its intraperitoneal levels in peritonitis have received little attention. We hypothesized that in peritonitis a significant and clinically relevant cytokine-mediated inflammatory response is compartmentalized in the peritoneal cavity. Methods. MEDLINE was used to search the literature for all articles dealing with experimental, primary, and secondary bacterial peritonitis and cytokines. Results. Bacterial peritonitis is associated with an immense intraperitoneally compartmentalized cytokine response, with plasma levels of cytokines representing only the tip of the iceberg. Although certain amount of cytokines may be beneficial to the peritoneal defense mechanisms, higher levels correlate with adverse outcome. Thus it is plausible to look at acute peritonitis as initially a combined infective (microorganism) and inflammatory (cytokines) proces. The clinical significance of the distinction between peritoneal inflammation and infection and the relevance of our findings to the stratification and treatment of peritonitis are discussed. Conclusions. Current surgical and antibiotic therapy for peritonitis is able to clear the peritoneal cavity of infective concentration of bacteria, but many patients continue to die of an uncontrolled activation of the inflammatory cascade. We suggest that one potential venue for therapeutic progress is the modulation of the compartmentalized peritoneal inflammatory response.