Serological Evidence of Chronic Chlamydia pneumoniae Infection in Coronary Artery Disease

BackgroundRecent studies have suggested that Chlamydia pneumoniae infection could be involved in atherosclerosis and related clinical manifestations such as coronary artery disease, carotid artery stenosis and myocardial infarction.MethodsSerum IgG, IgM and IgA antibodies to chlamydia genus specific antigen were measured by enzyme linked immunosorbent assay (ELISA) in 100 cases of angiographically demonstrated coronary artery disease (CAD) and 100 randomly selected healthy individuals as controls after matching for age and sex. All the samples positive for chlamydia genus specific IgG antibodies were then subjected to Chlamydia pneumoniae species specific IgG antibody ELISA.ResultsSeroprevalence of chlamydia genus specific IgG antibodies in control group was 59% with an increase in seropositivity with increasing age. The overall seroprevalence of IgG antibodies was 76% in CAD group and the prevalence was significantly high in all age groups as compared to controls. The odds ratio was 2.20 for seropositivity of chlamydia genus specific IgG antibodies in patients with myocardial infarction (MI) and/or angina than in control group. No significant association was observed for IgA and IgM anti-chlamydial antibodies. The odds ratio for prevalence of Chlamydia pneumoniae species specific IgG antibodies in CAD patients increased to 2.55 in comparison to age and sex matched controls.ConclusionCurrent study supports the reported association between C pneumoniae infection and CAD in Indian population.