Background: Atherosclerosis is pathologically similar to a chronic inflammatory response. Recent reports have suggested that Chlamydia pneumoniae may play a role in the pathogenesis of atherosclerosis.
Objective: To determine, by using various detection methods, whether C. pneumoniae is present in the coronary arteries of patients with coronary atherosclerosis.
Design: Multicenter investigation.
Setting: The Jewish Hospital Heart and Lung Institute in Louisville, Kentucky, and several laboratories.
Patients: 12 patients seeking heart transplantation.
Measurements: Culture for C. pneumoniae was done in HEp-2 cell monolayers. Other methods of detection included polymerase chain reaction (PCR) assay, immunocytochemistry, transmission electron microscopy, and in situ hybridization.
Results: Chlamydia pneumoniae was cultured from atherosclerotic plaques in one patient with severe coronary artery disease. The organism was found in the atheromas of this patient by PCR assay, immunocytochemistry, electron microscopy, and in situ hybridization. In addition, at least one testing method showed C. pneumoniae in coronary artery tissue in six of nine additional patients with coronary atherosclerosis.
Conclusions: This study provides direct evidence of the presence of viable C. pneumoniae in atheromatous lesions. A chronic inflammatory response caused by a persistent infection of the coronary arteries may explain the link between C. pneumoniae and atherosclerosis.