Effect of abdominal infections on peritoneal and systemic production of interleukin 6 and monocyte chemoattractant protein-1.

The aim of the study was to compare peritoneal and systemic production of interleukin 6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) in uninfected patients and in patients with peritonitis. Peritoneum was excised at laparotomy for acute peritonitis (n = 22) or noninfectious reasons (n = 61), and was incubated with or without lipopolysaccharide (LPS). Mediator concentrations in the culture-supernatants, in the patients' serum, and in plasmasupernatants of LPS-stimulated whole blood were related to outcome. Spontaneous production of IL-6 by the peritoneum was increased in infected patients compared with uninfected patients. In contrast to IL-6, LPS-stimulated production of MCP-1 was significantly less in infected patients. Serum concentrations of both mediators were higher in infected patients and the highest concentrations of MCP-1 were in patients who died. LPS-stimulated production of IL-6 in whole blood was least, whereas that of MCP-1 was greatest in infected patients who died. These contrasting results for local and systemic production of mediators illustrate the compartmentalized immune response to intra-abdominal infection.