An association between an antibody against Chlamydia pneumoniae and commoncarotid atherosclerosis

Objective Chlamydia pneumoniae (C. pneumoniae) is an important pathogen for infections of the respiratory tract, and there are recently also a number of reports suggesting its relation with atherosclerosis. This study was per formed to clarify the relation between C. pneumoniae infection and scleroti c lesions of the common carotid arteries. Methods and Patients We evaluated sclerotic lesions of common carotid arter ies by ultrasonography in 147 in-patients (mean age, 70 years; 95% confiden ce interval, 68-72) in the internal medicine ward, and studied the relation of the known risk factors for atherosclerosis including C. pneumoniae infe ction. An ultrasonograph and 7.5 MHz linear type B-mode probe were used by a specialist to evaluate sclerotic lesions of common carotid arteries. C. p neumoniae infection was determined by measuring anti-C. pneumoniae IgG spec ific antibody level (IgG index) using enzyme-linked immunosorbent assay (EL ISA) method with serum of fasting blood, which had been preserved at -70 de greesC. Results IgG index (p=0.0263), from multiple regression analysis using vario us risk factors as explanatory variables, was a significant independent con tributing factor (R-2=0.3465, p<0.0001) along with known risk factors such as male (p=0.0289), age (p=0.0007), Brinkman index (p=0.0067), hypertension (p=0.0443) and T-Chol (p=0.0220). Conclusion This study confirmed that the observations of an association bet ween antibody against C. pneumoniae and common carotid atherosclerosis in W estern nations is also present in Japan. Our results suggests that C. pneum oniae infection is also an important risk factor for common carotid atheros clerosis.