Chlamydia pneumoniae DNA is present in peripheral blood mononuclear cells during acute coronary syndrome and correlates with chlamydial lipopolysaccharide levels in serum.

Chlamydia pneumoniae can possibly trigger and maintain inflammation in coronary arteries. Chlamydia pneumoniae DNA and chlamydial lipopolysaccharide (cLPS) were measured 3 times during a 1-y period in 97 patients with acute coronary syndrome. Chlamydia pneumoniae DNA in peripheral blood mononuclear cells was detected in 8 (8.2%) patients at the initial hospitalization and in 9 (10.6%) patients at 3 months. One y after the acute coronary syndrome, Chlamydia pneumoniae DNA was not found in any patients. Serum cLPS levels were elevated at inclusion, and declined significantly during follow-up (1.40 microg/ml; (0.20-2.91), median; (range of 25th to 75th percentiles) at inclusion, 0.44 microg/ml; (0.00-1.39) at 1 y; ANOVA p<0.0001). cLPS levels correlated significantly to Chlamydia pneumoniae DNA positivity at 3 months (p=0.003). In conclusion, Chlamydia pneumoniae DNA is present during acute coronary syndrome and in the recovery period, but declines in stable state, suggesting a role of the bacterium in the acute phase of coronary syndrome.