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.