ABSTRACT
<p><b>OBJECTIVE</b>Recently studies showed infections of Chlamydia pneumoniae (Cp), Helicobacter pylori (Hp) and cytomegalovirus (CMV) played roles in the development of atherosclerosis. The aim of this study was to study relationship between infection of Cp, Hp and CMV, systemic inflammation and coronary artery disease (CAD).</p><p><b>METHODS</b>Fourty-five patients with at least one coronary artery stenosis > 50% and 33 control subjects with negative coronary angiography were recruited for this case-control study from May 2000 to October 2001. Antibodies against Cp, Hp and CMV were measured and serum C-reactive protein (CRP) levels determined for each case. CRP level > 0.8 mg/dl was defined at elevated CRP level.</p><p><b>RESULTS</b>The prevalence of Cp IgG, Hp IgG or Hp IgA antibody was associated with CAD (P = 0.017, P < 0.001, P = 0.009). After adjustment for age, gender, smoking, hypertension, hyperlipidemia and diabetes, the association was still seen. Mean CRP value was significantly higher in patients with CAD, compared to those without CAD (P < 0.001). Multivariate analysis showed statistical significance (P = 0.03). Elevated levels of CRP were found to be an important parameter for CAD (P = 0.032). The prevalence of Cp IgG antibody, Hp IgG and CMV IgG antibody all showed 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 was 32.1% while in the group with IgG antibodies to <or= 2 pathogens it was 14.9%. But with no significance difference between the two (P = 0.078).</p><p><b>CONCLUSIONS</b>Two chronic infections, Cp and Hp, might increase the risk of CAD. There was no association of CMV infection with CAD. C-reactive protein was an independent parameter of CAD, but the increased systemic inflammation in CAD did not seem to be related to aforesaid infection.</p>