In order to examine the specificity of cytokine production during coro
nary artery bypass graft (CABG) surgery, we serially measured serum le
vels of monocyte chemoattractant protein-1 (MCP-1), interleukin-8 (IL-
8), interleukin-6 (IL-6), interleukin-1 beta (IL-1 beta) and tumor nec
rosis 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 an
d IL-6, increased significantly during the surgery (P < 0.05), while I
L-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 sit
es, i. e., the hepatic vein, pulmonary artery and radial artery. They
increased in parallel in each patient, although the actual timing of t
he increase relative to the surgical step varied among individuals. In
complicated patients, MCP-1, IL-8 and IL-6 showed higher peaks and pe
rsisted longer than in patients without complications. The universal a
nd simultaneous appearance of MCP-1, IL-8 and IL-6 could indicate that
these three cytokines may be stimulated by a yet undiscovered stimulu
s (or stimuli) which occurs systemically despite the independent pathw
ays of production.