ABSTRACT
C. pneumoniae is an obligatory intracellular bacterium responsible for upper and lower respiratory tract infections. This work was carried out to study the association between C. pneumoniae infection and coronary heart disease [CHD]. This study included 70 patients, divided into two groups[Group I ,included 55 patients with acute coronary syndromes: 32 patients with acute myocardial infarction and 23 patients with unstable angina Group II, It included 15 patients with previously diagnosed chronic coronary heart disease]and healthy Control Group [Group III],It included 22 healthy subjects as control. Venous blood samples were collected from all patients and controls for: determination of total blood cholesterol level, detection of C. pneumoniae-specific IgG by ELISA and detection of C. pneumoniae DNA in the peripheral blood mononuclear cells by PCR The results of this study showed that: C. pneumoniae-specific IgG was detected by ELISA in 83.6% of the acute patients, 73.3% of the chronic patients, and 68.2% of the healthy control subjects.There was no statistically significant difference among the different studied groups as regarding the prevalence of C. pneumoniae-specific IgG antibodies.C. pneumoniae IgG seropositivity among the CHD patients was correlated with smoking but not with age, male sex, hypertension, diabetes mellitus or hypercholesterolemia. C. pneumoniae-specific DNA was detected by PCR in the PBMCs of 61.8% of the acute patients, 26.7% of the chronic patients, and 18.2% of the healthy control subjects. Positive PCR results were significantly higher among the whole studied CHD patients [acute plus chronic] compared to the control subjects. Also, positive PCR results were significantly higher among the acute patients than both the chronic patients and the healthy controls. In contrast, the difference between the chronic patients and healthy controls as regarding the prevalence of C. pneumoniae DNA in the PBMCs was not statistically significant. C. pneumoniae DNA positivity among the patients [either the whole patients or acute patients only] was not significantly correlated with age, sex or any of the studied classic coronary risk factors [smoking, hypertension, diabetes mellitus and hypercholesterolemia]. After adjustment for the classic coronary risk factors and demographic characteristics in the multiple logistic regression analysis, C. pneumoniae infection [as indicated by PCR positivity] was associated with the CHD.No statistically significant difference was found between C. pneumonia DNA positive and C. pneumoniae DNA negative patients [either the whole patients or acute patients only] as regarding the prevalence of C. pneumoniae-specific IgG. This study concluded that: C. pneumoniae DNA detection in the PBMCs was found to be an independent predictor for CHD, particularly acute coronary events.The prevalence of C. pneumoniae DNA in the peripheral blood was found to be higher among the acute CHD patients with recurrent attacks than those with first attacks.C. pneumoniae IgG seropositivity was unreliable predictor for the presence of C. pneumoniae DNA in the CHD patients