Serological markers of Chlamydia pneumoniae infection in men and women and subsequent coronary events -: The Scottish Heart Health Study cohort

Aims To investigate the relationship between serum markers of Chlamydia pneumoniae infection and subsequent coronary events. Methods and Results In a nested case-control study, based on the Scottish Heart Health Study cohort. we estimated IgG, IgA and IgM antibodies to C. pneumoniae, and circulating immune complexes containing C pneumoniae antigen in baseline serum samples from 217 cases experiencing a subsequent coronary event during follow-up (mean 7.5 years) and from their matched controls. In men, the proportion of specimens positive for IgG, IgA and IgM antibodies showed no case-control differences (80% vs 80%, 57% vs 53% and 3%, vs 3%, respectively). The odds ratio for a coronary event was 1.00 (95% confidence interval 0.59-1.69) for the presence of IgG antibodies to C. pneumoniae 1.21 (0.76-1.92) for IgA and 0.75 (0.17-3.35) for IgM. Similar results were seen in women. The proportion of specimens with circulating immune complexes with C pneumoniae antigen also showed no case-control differences (12% vs 12%. both sexes combined) with an odds ratio of 1.00 (0.57-1.76). Conclusion Prior infection with C. pneumoniae, as estimated by these markers, does not appear to be a risk factor for subsequent coronary heart disease. (C) 2001 The European Society of Cardiology.