Chlamydia pneumoniae and coronary heart diseaseBMJ 1997; 314 doi: https://doi.org/10.1136/bmj.314.7097.1778 (Published 21 June 1997) Cite this as: BMJ 1997;314:1778
Coincidence, association, or causation?
- Sandeep Gupta, Research fellow in cardiologya,
- A John Camm, Professor of cardiologya
- a Department of Cardiological Sciences, St George's Hospital Medical School, London SW17 0RE
Established cardiovascular risk factors such as cigarette smoking, diabetes mellitus, hypertension, and hypercholesterolaemia do not fully explain the temporal and geographical variations in the prevalence of coronary heart disease over the past century. Clinical data and animal models suggest that common chronic infections (including cytomegalovirus, herpesviruses, Helicobacter pylori, and dental sepsis) may also contribute to the pathogenesis of atherosclerosis.1 However, the evidence that these infections can directly cause atherosclerosis is inconclusive.
Much stronger evidence now exists linking Chlamydia pneumoniae, an obligate intracellular pathogen, with coronary heart disease. This organism is a common cause of respiratory tract infections, which are usually subclinical and self limiting. Since C pneumoniae is difficult to culture, confirmation of infection often requires identifying systemic antibody responses. About half of the population is seropositive to C pneumoniae by the age of 50 years, suggesting that reinfection is common.2
Several recent studies have shown an association between antibodies to C pneumoniae and coronary heart disease.3 4 5 6 In 1988 …