Prevalence of Chlamydia Pneumoniae and Mycoplasma Pneumoniae in Different Forms of Coronary Disease

Background: Several infectious agents have been investigated since the association between atherosclerosis and infection was demonstrated; however, the results of these studies are contradictory. Objective: To test the association between serum titers of anti-Chlamydia and anti-Mycoplasma antibodies in different forms of acute coronary syndromes (ACS). Methods: One hundred and twenty-six patients were divided in 4 groups: ACS with ST-segment elevation ( 32 patients), ACS without ST-segment elevation ( 30 patients), chronic coronary artery disease ( 30 patients) and blood donors without known coronary disease ( 34 patients-control group). In the two first groups, serum samples were collected at hospital admission ( first 24 hours of hospitalization) and after a 6-month follow-up. In the other two groups, only a basal sample was collected. Anti-Chlamydia and anti-Mycoplasma antibodies were measured by indirect immunofluorescence in all samples. Results: Significant differences were observed between the basal sample and the one measured after a 6-month follow-up in patients with myocardial infarction with ST-segment elevation for Chlamydia (650 +/- 115.7 versus 307 +/- 47.5, p = 0.0001) as well as Mycoplasma (36.5 +/- 5.0 versus 21.5 +/- 3.5, p = 0.0004). The groups with ACS had higher anti-Chlamydia and anti-Mycoplasma serum antibody levels in the basal measurement, when compared to the patients with chronic coronary disease and the control group, but the differences were not statistically significant. Conclusion: The present study showed an association between the serum titers of anti-Chlamydia and anti-Mycoplasma antibodies in the acute phase of patients with unstable angina or myocardial infarction. (ClinicalTrials.gov-NCT00561028). (Arq Bras Cardiol 2009; 92(6) : 405-411)