Circulating markers of inflammation and atherosclerosis

Atherosclerosis is nowadays generally accepted as an inflammatory disease. It is known that local inflammation occurs in the formation the plaques, as macrophages and other immuno-competent cells are present in the lesions from an early stage, and it is also known that inflammation plays an important role in the weakening of the fibrous cap of the advanced plaque, eventually leading to plaque rupture and acute coronary syndromes. The present review focuses on two questions. First, if circulating markers of inflammation could differentiate between healthy subjects and those with atherosclerotic manifestations. Second, if those markers could differentiate between those with a stable atherosclerotic disease, such as stable angina pectoris, and those prone to unstable manifestations of atherosclerosis, such as acute coronary syndromes. Using data from both cross-sectional and prospective studies it could be shown that the majority of the studies which had investigated the role of markers for systemic inflammation, such as CRP, leukocyte count, serum fibrinogen and different cytokines, found elevated levels in patients with atherosclerosis and especially so in those with an unstable coronary disease. The same pattern was found when inflammatory markers with a vascular origin, such as the adhesion molecules, were investigated. Thus, based on the literature it is obvious that circulating markers of inflammation have a role as risk factors for unstable manifestations of atherosclerosis, but it is still unclear whether the different inflammatory markers merely are markers, or if they in an active way contribute to the development and progression of the atherosclerotic disease in their own.