Chlamydia pneumoniae(Cp) infection, is that a risk factor of atherosclerosis?: On the basis of seroepidemiologic study / 대한내과학회지

ABSTRACT

BACKGROUND: Several risk factors of atherosclerosis have been known. However, many patients have been experienced coronary heart disease without known risk factors of atherosclerosis, and it has been suggested that some kinds of infections may be associated with atherosclerosis as risk factors. Among many candidate infectious agents, Chlamydia pneumoniae (Cp) has been showing a positive relationship with atherosclerosis. Therefore, we investigated massive serologic study using a ELISA for detection of Cp to identify the relationship with atherosclerosis as a risk factor. METHODS: Serologic tests were done in patients who were performed coronary angiogram among patients with typical symptoms of angina and with positive results in non- invasive test (EKG, Treadmill) from May 1997 to September 1998. Among them, patients with luminal narrowing of more than 50% in at least one vessel were grouped into 'Case group (Group I)' and patients with normal coronary arteries or minimal lesion were grouped into 'Positive control group(Group II)'. We also studied healthy persons, as a 'Negative control group (Group III), who had not experienced any symptoms related with coronary heart disease and had normal EKG findings. Serologic tests for Cp-IgG and Cp-IgA were performed by ELISA. RESULTS: There was no statistical difference in seropositive rate between Group I and II, but seropositive rate of Group III was statistically lower than those of Group I or II for Cp-IgG, Cp-IgA, and both, respectively. But multivariate analysis by using logistic regression showed no statistcal differences between groups. Subgrouping by several traditional risk factors, seropositive rate for Cp-IgG and both IgG and IgA, was significantly different between Group I and III in patients without traditional risk factors of atherosclerosis, such as, females, non-smokers, normotension, non-diabetes, normal cholesterol level, and high HDL-cholesterol level. For Cp-IgA, however, the difference was observed in normotension, non-diabetes, and in normal cholesterol level. In multivariate analysis, seropositive rate for Cp-IgG and both IgG and IgA was significantly different between Group I and III in females and non-smokers, but not for the Cp-IgA. CONCLUSIONS: These results suggest that Cp infection might be an independent risk factor of atherosclerotic coronary disease, particularly in patients without traditional risk factors of atherosclerosis. Further study with coronary tissue should be continued.