Reduced interleukin-12 release from stimulated monocytes in patients with sepsis after major cancer surgery

Major cancer surgery is a high-risk situation for sepsis in the post-operative period. The aim of this study was to assess the relation between the monocyte production of IL-12 and the development of post-operative sepsis in patients undergoing major cancer surgery.

In 19 patients undergoing major cancer surgery, the production of cytokines by basal and lipolysaccharide (LPS)-stimulated monocytes was measured before and after (from day 1 to day 3 and day 7) surgery. Seven of them developed a post-operative sepsis. Ten healthy volunteers were used as controls for the assessment of pre-operative values.

Before surgery, the production of interleukin (IL)-12 p40 by LPS-stimulated monocytes was similar in the patients and the healthy volunteers. The production of IL-12 p40 by unstimulated monocytes was higher in the patients than in the healthy volunteers. IL-12 production did not differ between the septic and the non-septic patients. After surgery, the production of IL-12 p40 was dramatically reduced in the LPS-stimulated monocytes of the septic patients from day 1 to day 3, as compared with that of the non-septic patients. Before surgery, the production of IL-6, IL-10, and IL-1 receptor antagonist (IL-1ra) in the patients was significantly higher than that of the healthy volunteers for both stimulated and unstimulated monocytes. After surgery, the production of these cytokines by both stimulated and unstimulated monocytes of the septic patients was similar to that of the non-septic patients. Intragroup analysis showed significant changes for IL-6, IL-10, and IL-1ra under all conditions, with the exception of changes in unstimulated monocytes of septic patients that were not significant for IL-10 release.

After surgery, the septic patients showed drastic failure to up-regulate monocyte LPS-stimulated production of IL-12 p40.