Most publications on the relationship between infection with Chlamydia pneumoniae and coronary heart disease (CHD) propose an association, but negative studies are also reported. Seroepidemiological studies vary in the use of different serological methods, different cutoff limits, different sampling times in relation to acute cardiac events, and different clinical stages of CHD. We wanted to compare three different commercially available methods for measuring Chlamydia antibodies to see how the choice of method influenced the prevalence of seropositive individuals in CHD patients and in healthy individuals and to see if sampling time in relation to an acute cardiac event or the stage of atherothrombotic disease influenced the results. Blood samples from 197 CHD patients and 197 individually matched healthy control individuals were tested at baseline and after 6 months; the mean age was 55 years in both groups, and 18% were women. Among the CHD patients, 166 were included at a median of 16 days after an acute cardiac event and 31 had chronic disease with the latest acute event being >3 months earlier. The difference in prevalence of antibodies between the CHD patients and the healthy controls was significant when Chlamydia lipopolysaccharide antibodies were measured, while no significant differences between the study groups were observed by the two methods detecting Chlamydia pneumoniae major outer membrane protein antibodies. The number of seropositive individuals was quite similar at inclusion and 6 months later, and no significant differences were observed between patients with a recent cardiac event and those with a more remote cardiac event. We conclude that the choice of serological method is of major importance when evaluating a possible relationship between C. pneumoniae and CHD.The old hypothesis that atherosclerosis could be caused by infectious agents has received new attention during the last 15 years, and Chlamydia pneumoniae is one of the main pathogens under suspicion. Since Saikku et al. (31) proposed an association between C. pneumoniae and coronary heart disease (CHD), many reports from different countries have been published, with diverging results (10,11,14,17,25,37). Although some investigations are based on direct immunofluorescence or PCR demonstrating C. pneumoniae in situ in the atherosclerotic plaque, most studies are based on serology, using different methods to detect human antibodies against the organism. Two basic methods are used: microimmunofluorescence tests (MIF) or enzyme immunoassays (EIA and ELISA techniques). Some tests detect antibodies to the species-specific major outer membrane proteins (MOMP), and some detect antibodies to the chlamydia lipopolysaccharide (LPS), which is common to Chlamydia pneumoniae, Chlamydia trachomatis, and Chlamydia psittaci. Furthermore, the titer end points used as cutoff values for seropositivity when comparing various groups differ in various studies.The aim of the present study was to compare three different, commonly used methods for measuri...
We demonstrated that physical performance is inversely correlated with levels of pro-inflammatory markers in coronary heart disease patients, possibly retarding the process of atherosclerosis. No effect on inflammatory markers was obtained with a 6-month lifestyle intervention programme when compared with patients who received usual care follow-up.
Elevated levels of soluble cell adhesion molecules (sCAMs), inflammatory cytokines and C-reactive protein (CRP) have been associated with atherosclerotic disease states. The aim of the present study was to evaluate whether circulating levels of vascular cell adhesion molecule-1 (sVCAM-1), intercellular adhesion molecule-1 (sICAM-1), E- and P-selectin were significantly elevated in patients with coronary heart disease (CHD) compared with healthy controls, and to study possible associations between these sCAMs, tumour necrosis factor alpha (TNFalpha). interleukin-6 (IL-6), CRP and major CHD risk factors. The study included 193 patients in various stages of CHD and 193 matched controls. To evaluate any possible influence of acute phase reaction, reinvestigation was performed after 6 months. After adjustment for major CHD risk factors, sVCAM-1, sICAM-1, P-selectin, IL-6 and CRP remained significantly elevated in the CHD patients (p for all <0.001). In multivariate analysis sVCAM-1 was predicted by age (p=0.015), sICAM-1 by smoking (p<0.001) and total cholesterol (p=0.026), E-selectin by body mass index (BMI) (p=0.004) and P-selectin by male gender (p=0.015). TNFalpha significantly predicted sICAM-1 and E-selectin levels, while IL-6 predicted CRP but none of the sCAMs measured. This might indicate that TNFalpha, but not IL-6, plays a major role in the regulation of sCAM levels in vivo.
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