Chlamydia pneumoniae antibodies and angiographically demonstrated coronary artery disease in Thailand.

Recent reports have suggested an association between Chlamydia pneumoniae and coronary artery disease. This study investigated the relationship between the presence of immunoglobulin G (IgG), immunoglobulin A (IgA) of C. pneumoniae in angiographically diagnosed coronary disease. Patients enrolled were 243 (178 male, 65 female, mean age 61 +/- 10 years) with angiographically proven at least one significant coronary artery stenosis. Fifty-eight patients (33 male, 25 female, mean age 57 +/- 11 years) with no angiographic evidence of coronary lesions were used as the normal coronary angiogram group. Control subjects (95 male, 92 female, mean age 58 +/- 17 years) were used as normal healthy persons who had no history of coronary artery disease. C. pneumoniae IgG and IgA antibodies were measured by ELISA method. We found that 179 out of 243 (73.7%) coronary artery disease (CAD) patients were positive for IgG and 132 out of 243 (54.3%) were positive for IgA. In 58 normal coronary angiogram patients, 23 (39.7%) cases were positive for IgG and 6 (10.3%) cases were positive for IgA. Among 187 healthy controls, 111 (59.4%) cases were positive for IgG and 83 (44.4%) were positive for IgA. When C. pneumoniae IgG antibodies were considered, there was significant difference between CAD patients and healthy controls (OR = 1.91, 95% CI = 1.27 - 2.88, p = 0.0018). In cases of positive IgA antibodies, significant difference was also found between CAD patients and healthy controls (OR = 1.49, 95% CI = 1.02 - 2.19, p = 0.0257). These findings were also found with higher odds ratio when we compared between CAD patients and normal coronary angiogram patients. The result suggested that C. pneumoniae infection is common in Thai people and chronic C. pneumoniae infection is more common in CAD patients. Chronic C. pneumoniae infection may be associated with the development of atherosclerotic coronary disease and treatment with antibiotics should be considered in ischemic heart disease.