Chlamydia pneumoniae antibodies and angiographically demonstrated coronary artery disease in a sample population from Italy

Recent reports suggest an association between Chlamydia pneumoniae and chronic coronary heart disease. This case-control study investigates the relationship between the presence of immunoglobin G (IgG) and immunoglobin A (IgA) when measured by means of microimmunofluorescence (MIF) and angiographically diagnosed coronary disease. Cases (n = 150) were angiography patients with at least one coronary artery lesion occupying at least 50% of the luminal diameter. Controls (n = 49) were angiography patients with no detectable signs of coronary artery disease and patients (n = 56) without signs or symptoms of coronary disease and with normal ECG results. No significant differences were revealed between the seroprevalence of IgG and IaA and geometric mean titers (GMT) as measured in cases and controls. When cases were compared with controls whose angiographic results were normal, after adjusting for established risk factors (cholesterol, smoking, hypertension, diabetes, age, gender and family history), the estimated risk of coronary artery disease was 0.79 (95% confidence interval (C.I.), 0.31-1.99) for the presence of IgG and was 0.94 (95 C.I., 0.37-2.39) for IgA. When cases were compared with controls with normal ECG results, the adjusted odds ratio (O.R.) for coronary artery disease was 1.17 (95%, C.I., 0.52-2.62) for the presence of IgG and 0.82 195% C.I., 0.36-1.86) for the presence of IgA. These results do not support an association between C. pneumoniae infection and coronary disease.