Association between chlamydia pneumoniae infection and carotid atherosclerotic plaques

BACKGROUND: Several studies have suggested an association between Chlamydia pneumonia infection and atherosclerosis. This study was designed to investigate the association between this organism and atherosclerotic plaque formation in right and left common carotid arteries (CCAs) and extracranial portions of internal carotid arteries (lCAs). METHODS: Antibodies to Chlamydia pneumoniae (lgA and IgG) were measured and compared in 42 patients who had plaque in at least one CCA or lCA (detected by duplex ultrasound) and 82 patients without any plaque in these arteries. Cp.IgG and Cp.lgA titers over 1.10 TSR were defined to be positive. RESULTS: We found that 6.1% of control subjects and 16.7% of cases were Cp.IgA seropositive. The difference between these two groups was prominent but was not statistically significant (P = 0.104). 4.2% of females without atherosclerotic plaque and 31.6% of females with plaque were Cp.IgA seropositive. This difference is statistically significant (P = 0.005). There was no significant difference in seropositivity of Cp.IgG between case and control subjects or in male and female groups with or without plaque. CONCLUSIONS: Cp.IgA is a predictor of atherosclerosis in women, but Cp.TgGhas no predictive value for plaque formation in either gender.