Circulating Chlamydia pneumoniae DNA as a predictor of coronary artery disease

OBJECTIVE: To determine whether current vascular Chlamydia pneumoniae (CPn) infection as diagnosed by circulating CPn DNA is more common in subjects w ith coronary artery disease (CAD). BACKGROUND: Serological, pathological and animal studies have associated CP n with CAD and preliminary trials suggest antibiotics may prevent adverse c oronary events. C. pneumoniae is thought to disseminate systemically within macrophages. We therefore detected CPn DNA in blood to determine whether i ts presence was a predictor of CAD. METHODS: One thousand, two hundred and five subjects attending for diagnost ic and interventional coronary arteriography were recruited. The mononuclea r cell laver and platelets were separated from collected blood and the poly merase chain reaction (PCR) was used to detect CPn DNA. RESULTS: Circulating CPn DNA was found in 8.8% of 669 men with CAD compared with 2.9% of 135 men with normal coronary arteries (odds ratio [OR] 3.2, 9 5% confidence interval [CI] 1.1-8.9). In men with CAD, those with CPn DNA h ad higher mean platelet counts than those without CPn DNA. Monocyte counts and indirect fibrinogen levels were also raised but not significantly so. B y contrast, no association of circulating CPn DNA and CAD was seen in women . CONCLUSIONS: Circulating CPn DNA is a predictor of CAD in men. Unlike serol ogy, it is a specific indicator of current infection and is a means of iden tifying subjects who may potentially benefit from antichlamydial therapy, ( C) 1999 by the American College of Cardiology.