Infections Of Chlamydia Pneumoniae,Helicobacterpylori And Cytomegalovirus,Inflammationand Coronary Artery Disease

BackgroundIt is wellknown about traditional risk factors of coronary artery disease (CAD) such as age, gender, smoking, hypertension, hyperlipidemia and diabetes etc. Yet they do not completely explain the pathogenesis of the disease. Recently studies showed infections of Chlamydia pneumoniae (CPn), Helicobacter pylori (HP) and Cytomegalovirus (CMV) played roles in the development of atherosclerosis. The organism may be actively involved in atherogenesis as a primary inducing agent or may exacerbate an existing inflammatory process. But it is controversial. C-reactive protein (CRP), a systemic marker for inflammation, have been found to predict future coronary events. The aim of the present study is to investigate the relationship between infection of CPn, HP and CMV, systemic inflammatiom and CAD.MethodSubjects were recuited for this case-control study from May 2000 to October 2001: 45 patients with at least one coronary artery stenosis >50% and 33 control subjects with negative coronary angiography. Antibodies against CPn, HP and CMV are measured. Serum CRP levels determined for each case. CRP level >0.8mg/dl is defined elevated CRP level.Results1. The prevalence of CPn-IgG, HP-IgG or HP-IgA antibody is associated with CAD (P=0.017, PO.001, P=0.009). After adjustment for age, gender, smoking, hypertension, hyperlipidemia and diabetes, the association is still present.2. Mean CRP value was significantly higher in patients with CAD, compared to those without CAD (0.72?.64 mg/dl vs 0.28?.26 mg/dl, P<0.001). By multivariate analysis, it retained statistical significance (P=0.03). Elevated levels of CRP were found to be an important parameter for CAD (P=0.032).3. The prevalence of CPn-IgG antibody, HP-IgG and CMV-IgG antibody all shows no association with elevated levels of CRP(P=0.391, P=0.253, P=0.724) .The ratio of elevated levels of serum basic CRP in the group with IgG antibodies to 3 pathogens is 32.1% and it in the group with IgG antibodies to ^2 pathogens is 14.9%.There is no significance between them (P=0.078).Conclusions1. Two chronic infections, CPn and HP, may increase the risk of CAD. There is no association of CMV infection with CAD.2. C-reactive protein is an independent parameter of CAD, but increased systemic inflammation in CAD does not seem to be due to aforesaid infection.