Transient rise in serum cytokines during coronary artery bypass graft surgery

In order to examine the specificity of cytokine production during coronary artery bypass graft (CABG) surgery, we serially measured serum levels of monocyte chemoattractant protein-1 (MCP-1), interleukin-8 (IL-8), interleukin-6 (IL-6), interleukin-1 beta (IL-1 beta) and tumor necrosis factor (TNF), in twenty patients between 52 and 80 years of age, during surgery and 2 days afterwards. Serum MCP-1, as well as IL-8 and IL-6, increased significantly during the surgery (P < 0.05), while IL-1 beta and TNF did not. MCP-1, IL-8 and IL-6 concentrations were not different in the sera of three patients tested at three different sites, i.e., the hepatic vein, pulmonary artery and radial artery. They increased in parallel in each patient, although the actual timing of the increase relative to the surgical step varied among individuals. In complicated patients, MCP-1, IL-8 and IL-6 showed higher peaks and persisted longer than in patients without complications. The universal and simultaneous appearance of MCP-1, IL-8 and IL-6 could indicate that these three cytokines may be stimulated by a yet undiscovered stimulus (or stimuli) which occurs systemically despite the independent pathways of production.