The prevalence of Chlamydia pneumoniae antibodies in Thai patients with coronary artery disease.

ABSTRACT

Blood samples were obtained from 243 consecutive coronary artery disease (CAD) patients (177 male, 66 female) aged 35-78 years (mean, 61 years) admitted for coronary angiography because of suspected coronary heart disease, and from 115 blood donors (91 male, 24 female) aged 25-60 years (mean, 47 years). Of the 243 CAD patients, 179 (74%) were positive by an ELISA method for Chlamydia pneumoniae antibodies IgG and 132 (54%) were positive for C. pneumoniae IgA. Among the 115 blood donors, 80 (70%) were positive for C. pneumoniae IgG and 49 (43%) were positive for C. pneumoniae IgA. When IgG antibodies were considered, there was no significant difference between CAD patients and healthy controls (OR = 1.29, 95% CI = 0.79-2.10, p > 0.05). In cases of positive IgA antibodies alone, there was a significant difference between CAD patients and healthy controls (OR = 1.58, 95% CI = 1.01-2.4, p = 0.029). If both IgG and IgA antibodies were positive, OR was increased from 1.58 to 1.80 (95% CI = 0.97-3.36, p = 0.044). In conclusion, C. pneumoniae infection is common in Thai people but chronic C. pneumoniae infection is more common in CAD patients than in middle-aged blood donors.