Development of Atherosclerosis and Infectious Agents

In recent years, the close relation between the development of atherosclerosis and inflammation has been recognized (1).As for the pathogens, Chlamydia pneumoniae (Cpn), cytomegalovirus (CMV), other Herpesvirus andHelicobactor pylori have been the focus of attention.The evidence has been based on the direct observation of pathogens in the atherosclerotic lesions and higher titer of seropositivity or immunecomplex in the patients with cardiovascular events.The mechanisms of development of atherosclerosis induced by infection remain to be clarified.However, the existence of commoninfections, such as chronic respiratory infection, urinary tract infection, and dental infection has been demonstrated to have a greater than 4fold risk of carotid atherosclerosis (2).Since the inflammatory marker, C-reactive protein (CRP), has been reported to be elevated in patients with acute myocardial infarction, CRPis nowthought to be an independent risk factor of cardiovascular events (3, 4).The mechanism of elevation of CRP remains unclear.However, chronic infections are thought to be a potential source of chronically elevated CRP.