Inflammation and coronary artery disease.

Several evidences, ranging from in vitro experiments, pathologic analysis and epidemiologic studies, show that atherosclerosis is intrinsically an inflammatory disease. The plasma concentrations of interleukin-6 (IL-6) and its hepatic by-product, C-Reactive Protein (CRP), appear to reflect the intensity of occult plaque inflammation and by inference may determine the vulnerability of plaque rupture. The monocyte chemoattractant protein-1 (MCP-1) plays a crucial role in initiating coronary artery disease by recruiting monocytes/macrophages to the vessel wall. This leads to the formation of atherosclerotic lesions and also increases the vulnerability of the plaque. Indeed, circulating IL-6 and MCP-1 levels are elevated in patients with acute myocardial infarction, and also in patients with unstable angina, but not in those with stable angina. The plasma IL-6 and MCP-1 concentrations are also increased after percutaneous coronary intervention (PCI), and late restenosis is correlated with an increase in IL-6 or MCP-1 concentrations after the procedure. This finding suggests that the expression of IL-6 and MCP-1 may not only be related to the instability of atheromatous plaques, but also to the formation of restenotic lesions after PCI. The development of drugs specifically targeted against IL-6 and MCP-1 may be useful in the prevention of plaque formation, myocardial infarction and restenosis.