Cytokine balance and immunosuppressive changes at cardiac surgery: contrasting response between patients and isolated CPB circuits.

In vitro work suggests that IL-10 plays a pivotal role in controlling the balance of pro- and anti-inflammatory cytokines and monocyte HLA-DR expression. In 20 patients undergoing cardiac surgery, we investigated elaboration of interleukin 10 (IL-10) and its relationship to pro- and anti-inflammatory cytokines and leucocyte expression of HLA-DR and adhesion molecules. There were small increases in pro-inflammatory cytokines (IL-1, IL-8 and tumour necrosis factor (TNF) after induction, returning to baseline on induction of cardiopulmonary bypass (CPB). After CPB another transient increase in IL-8 occurred (P 0.05). In contrast with the in vivo response where there was a phased anti-inflammatory response beginning with IL-10, in the isolated CPB model no anti-inflammatory cytokine response occurred.