Postoperative PMBC-derived IL-6 and TNF-alpha-release is uninfluenced by IL-12-mediated restoration of IFN-gamma synthesis.

OBJECTIVES

Interferon gamma (IFN-gamma) synthesis in peripheral blood mononuclear cells (PBMCs) is suppressed after major surgical trauma. Interleukin-12 (IL-12) has been shown to stimulate IFN-gamma-synthesis. We hypothesised that exogenous IL-12 can increase perioperative pro-inflammatory cytokine release. We therefore assessed the effect of IL-12 on IFN-gamma-synthesis and pro-inflammatory cytokine release in vitro before and after cardiac surgery.

DESIGN

In this prospective study, PBMCs from 20 elective cardiac surgery patients were stimulated for 24 hours with staphylococcal enterotoxin B and lipopolysaccharide before surgery (d0) and on the 1st (d1), 3rd (d3) and 5th (d5) postoperative days. IL-12 was added at each time point investigated. IFN-gamma, IL-6, tumour necrosis factor-alpha (TNF-alpha), IL-2, IL-4, IL-5, and IL-10 concentrations were assayed.

RESULTS

IFN-gamma-synthesis was significantly reduced at d1, d3 and d5. When IL-12 was added, IFN-gamma-synthesis returned to preoperative levels at d1, d3 and d5. Neither IL-6 nor TNF-alpha-synthesis was influenced by IL-12.

CONCLUSIONS

IFN-gamma synthesis is significantly reduced after major surgical trauma. IL-12 increases IFN-gamma-synthesis before and after surgery without influencing pro-inflammatory cytokine synthesis.