Chlamydia pneumoniae antibody response in patients with acute myocardial infarction and their follow-up, ,

Study Populations This study concerned the possible relations between seroreactivity to Chlamydia pneumoniae and myocardial infarction. A group of 29 patients with acute myocardial infarction (AMI), 74 members of a healthy control group, and a subgroup of 24 members of a healthy control group matched for age, sex, and coronary risk factors (HCM) were included in the study. In addition, we evaluated the AMI group in a 1-year patientsʹ follow-up study. We used two different tests to detect anti–C. pneumoniae antibodies: recombinant enzyme immunoassay antilipopolysaccharide antibodies and a reference microimmunofluorescence test. Results High titers of C. pneumoniae microimmunofluorescence antibodies were found in 89.65% of the AMI group and in 25% of the HCM group (p = 0.0000065). Immunoglobulin A-microimmunofluorescence was 51.72% in the AMI group and 20.83% in the HCM group (p = 0.0042). Immunoglobulin G and immunoglobulin A antilipopolysaccharide titers were 65.51% and 62.60% in the AMI group and 20.83% in the HCM group, respectively (p = 0.006). High concentrations of interleukin-6 were found in 86.20% of our AMI group (μ value = 54.38 pg/ml) when compared with the control group. A good correlation between interleukin-6 levels and immunoglobulin A-lipopolysaccharide titers (r = 0.658) was found. Conclusion The presence of a high prevalence rate and high titers of immunoglobulin G and immunoglobulin A-specific anti-C. pneumoniae antibodies in AMI at admission demonstrated the presence of a specific anti–C. pneumoniae immunization in the AMI population. (Am Heart J 1998;135:15-20.)