Enhanced progression of early carotid atherosclerosis is related to Chlamydia pneumoniae (Taiwan acute respiratory) seropositivity.

BACKGROUND Chlamydia pneumoniae (Cp) infection has been associated with atherosclerosis and has been proposed as a possible additional cardiovascular risk factor. However, the relationship between Cp seropositivity and the progression of early carotid atherosclerosis is not unequivocally clarified. METHODS AND RESULTS We evaluated the association between serological detection of Cp IgG and/or IgA antibodies and the progression of the intima-media thickness (IMT) of the common carotid artery using duplex ultrasonography in a prospective study with a follow-up of 3 years in 272 consecutive patients with cerebrovascular disease. Cp-seropositive patients showed a significantly enhanced progression of the IMT even after adjustment for other cardiovascular risk factors (0.12 mm/y [95% CI 0.11 to 0.14] versus 0.07 mm/y [0.05 to 0.09]; P:<0.005). Patients with increased C-reactive protein (>/=0.5 mg/dL) and Cp seropositivity showed the most pronounced IMT progression. Multivariate regression analysis revealed Cp seropositivity to be an independent risk factor for progression of early carotid atherosclerosis. Cox proportional-hazard regression analysis demonstrated a significantly increased rate of cerebrovascular and cardiovascular events in patients with Cp seropositivity, particularly in patients with increased C-reactive protein levels. CONCLUSIONS Our data support the importance of chronic inflammation and infection for the early stages of atherosclerotic development.