Chlamydia pneumoniae seropositivity is associated with carotid artery intima-media thickness

Infection may both augment the atherosclerotic process and contribute to later manifestations of overt clinical disease. Chlamydia pneumoniae elementary bodies have been detected in atherosclerotic lesions. The aim of the present study was to investigate whether elevated titers of antibodies and circulating immune complexes to C pneumoniae were associated with ultrasound findings indicating presence of atherosclerosis in the carotid artery. Serum titers of antibodies to C pneumoniae (IgM, IgA, IgG, and circulating immune complex) were related to intima-media thickness (IMT) and plaque status measured by B-mode ultrasound in the carotid artery in 113 men with treated hypertension and at least 1 of the following risk factors: hypercholesterolemia, smoking, or diabetes. Any of the titers was elevated in 56 (50%) men, and common carotid artery IMT was thicker in this group compared with the 57 men without any elevated titers (1.00 versus 0.92 mm, P