Infections, immunity, and atherosclerosis - Associations of antibodies to Chlamydia pneumoniae, Helicobacter pylori, and cytomegalovirus with immune reactions to heat-shock protein 60 and carotid or femoral atherosclerosis

Background-Atherogenesis involves inflammatory processes in which infection s are incriminated as possible contributors, Methods and Results-We evaluated cardiovascular risk factors as well as ser opositivity to Chlamydia pneumoniae, Helicobacter pylori, and cytomegalovir us in a population-based study. A significant association between prevalenc e and severity of atherosclerosis in carotid and femoral arteries and IgA a ntibodies to C pneumoniae was demonstrated that was not substantially alter ed after adjustment for established risk factors. For anti-H pylori IgG ant ibodies, significant correlations to vascular disease were restricted to lo w social status and lesions in carotid arteries. In addition, the study des ign allowed us to monitor lesion progression over time. In this prospective analysis, C pneumoniae seropositivity emerged as a significant risk predic tor. Antibody titers against cytomegalovirus were not a marker for prevalen ce or incidence of atherosclerosis in this population. Further infection pa rameters added to the predictive value of chlamydial serology in risk asses sment: Mean odds ratios for the prevalence of carotid atherosclerosis were 4.2 and 6.3 for seropositive subjects with elevated C-reactive protein leve ls and clinical evidence for chronic respiratory infection, respectively, F or subjects with all 3 infection parameters, the odds ratio of carotid athe rosclerosis reached 10.3 (P<0.0001). Concomitantly, serum antibodies to myc obacterial heat-shock protein 65 (mHSP65) correlated with seropositivity to C pneumoniae and H pylori but not to cytomegalovirus. Conclusions-This prospective population-based study provides strong evidenc e for a potential atherogenic role of persistent bacterial infection, espec ially C pneumoniae, as indicated by serological and clinical data and demon strates a correlation between immune reactions to mHSP65 and bacterial infe ctions in atherogenesis.