Chlamydia Pneumoniae and Coronary Atherosclerosis. A Serological Study

pp 299-303

Abstract

Many experimental and epidemiological studies show a positive association between Chlamydia pneumoniae (Cp) and atherosclerotic coronary artery disease (CAD), but the causal relationship is not clear enough. Objective To study the IgG and IgA serologic response to C pin patients with CAD versus controls. Inclusion criteria: patients with evidence of past myocardial infarction, or cinecoronariography with atherosclerotic lesions. Controls: without clinical evidence of atherosclerosis and normal cinecoronariography. Patients suspected of past Cp respiratory tract infection 2 years before, antibiotico therapy (tetracyclines, macrolides, fluorquinolones) in the previous 2 years were excluded. Methods Immunoglobulin A (IgA) and G (IgG) antibodies (Ab)to Cp were measured using the microimmuno-fluorescence method. We studied 28 controls and 87 patients. At the same time, with the purpose of establishing if raised titers of IgG anti Cp could represent a cross-reaction to Chlamydia trachomatis (Ct), IgGAb against Ct in24 selected patients were performed. Results Were considered three categories of IgG titers: low (LT) < 128:27 patients (31%), control 23 (82%); medium (MT)128-256: 44 patients (51%), control 5 (18%) and high (HT) >256:16 patients (18%), control 0 (0%) (p < 0.001). The prevalence of IgAAbLT < 40 was: 18patients (37%), control 28 (100%) and HT >40:30 patients(62%), control 0 (p < 0.001). Conclusion Almost all the controls had LT IgG and IgAAb, 69% of the patients had MT and HT of IgG and32% of them HT of IgA. There were not serologic links between Cp versus Ct. These results suggest a strong relation between CAD and Cp. It is possible that some patients with CAD could have chronic Cp infection as indicated by the presence of elevated levels of IgG and IgA, but this data are insufficient to attribute Cp a causal role in atherogenesis. New experimental models, larger epidemiological studies and further therapy with appropriate antibiotics are necessary for establishing a causal association between this common infection and CAD.