Relation of Chlamydia pneumoniae infection to documented coronary artery disease in Shiraz, Southern Iran

The global prevalence of Chlamydia pneumoniae, Helicobacter pylori, Cytomegalovirus and Herpes simplex virus in patients with coronary artery disease: A systematic review and meta-analysis

BACKGROUND AND AIM

Coronary Artery Disease (CAD) is one of the most important causes of death worldwide. The aim of this study was to determine the prevalence of C. pneumoniae, H. pylori, Cytomegalovirus (CMV) and Herpes simplex virus (HSV) in CAD patients based on published serological and molecular studies.

METHODS

A systematic literature search was conducted in Medline (via PubMed), Embase, Scopus and Web of Science databases (1996-2019). Both molecular and serological studies were analyzed using STATA software (Version 14).

RESULTS

145 studies were included for final analysis. We gathered and investigated the prevalence of C. pneumoniae (25.1% [95% confidence interval (CI) 21.5-28.8%]), H. pylori (12.8% [(95% CI) 4.0-22.0%]), CMV (64.4% [(95% CI) 57.7-73.0%]) and HSV (31.8% [(95% CI) 21.5-42.2%]) in CAD patients from the analysis of molecular studies. Additionally, in serological studies, the prevalence of mentioned pathogens were 72.7% [(95% CI) 67.8-77.6%], 63.3% [(95% CI) 60.0-66.5%], 62.2% [(95% CI) 58.0-66.3%] and 34.3% [(95% CI) 23.6-45.1%] respectively.

CONCLUSION

Interestingly, there was only a significant increase in the prevalence of C. pneumoniae and H. pylori in serological studies compared to the reported data from molecular studies, while the prevalence of CMV and HSV were the same in both types of studies.

Bacterial infections are associated with cardiovascular disease in Iran: a meta-analysis

INTRODUCTION

The present study aimed to assess the prevalence and association of various bacterial infections with cardiovascular disease (CVD) in Iran.

MATERIAL AND METHODS

An electronic search was performed using related keywords in the national and international databases up to June 30, 2017. Out of the 1807 articles found on the associations between bacterial infections and CVD, 20 relevant studies were selected for the meta-analysis.

RESULTS

The prevalence of bacterial infections was higher in case groups compared with the control groups. Odds ratios for assessing the association between Chlamydia pneumonia infection and CVD based on PCR, IgG and IgA tests were 7.420 (95% CI: 3.088-17.827), 3.710 (95% CI: 1.361-10.115) and 2.492 (95% CI: 1.305-4.756), respectively. Moreover, the calculated odds ratio for Mycoplasma pneumonia infection was 1.815 (95% CI: 0.973-3.386). For Helicobacter pylori infection, odds ratios based on IgG and IgA tests were 3.160 (95% CI: 1.957-5.102) and 0.643 (95% CI: 0.414-0.999), respectively.

CONCLUSIONS

The present meta-analysis suggested that there was a significant association between H. pylori, C. pneumonia and M. pneumonia infections and CVD in Iran. These findings confirm the potential role of bacterial infections as predisposing factors for CVD.

Association of Chlamydia pneumoniae Infection With Atherosclerotic Plaque Formation

Atherosclerosis is a complex multifactorial disorder. Studies show that infectious microbial agents may play an important role in the development of atherosclerosis; however, these findings are conflicting. This study investigated the presence of Chlamydia pneumoniae DNA in atherosclerotic plaques of patients suffering from coronary artery disease. In a cross-sectional study, 85 patients (43 females and 42 males with mean age of 61±9.5, range 42-82 years) referred for coronary artery bypass grafting (CABG) and thoracic biopsy as the control groups were enrolled for this study. Standard questionnaires, including demographic and clinical evaluation were administered. Obtained specimens were processed and then nested polymerase chain reaction with primers for Pst1 fragment was carried out to detect Chlamydia pneumoniae DNA. Statistical analysis was done using the SPSS software. Of note, in 25 out of the 85 patients (29.4%), C. pneumoniae was detected within atherosclerotic plaques, whereas, 5 out of the 85 thoracic biopsy (5.9%) were positive for the presence of the mentioned bacteria in internal thoracic artery. There was a statistically significant association between atherosclerotic plaque (study group) and thoracic biopsy (control group) in terms of C. pneumoniae positivity (P=0.0001). The findings of this study support the hypothesis that C. pneumoniae is associated with atherosclerosis.

Is there any relationship between Chlamydophila pneumoniae and coronary atherosclerosis among Iranians?

Background:

Atherosclerosis is a coronary heart disease, andis the most common cause of death in the industrialized world. Some studies suggested that atherosclerosis may be triggered by infectious agents, mostly Chlamydophila pneumoniae. However, the role of C. pneumoniae in the pathogenesis of coronary atherosclerosis is still controversial.

Objectives:

This study was performed to evaluate whether there is a significant association between coronary artery atherosclerosis and C. pneumoniae by the polymerase chain reaction (PCR) method.

Materials and Methods:

This case-control study was carried out on formalin-fixed paraffin-embedded tissue biopsies of the coronary arteries obtained from 30 patients with coronary atherosclerosis and 30 subjects without atherosclerosis living in Northeast of Iran. All subjects' weight and height were determined, and the body mass index was calculated. We also reviewed the medical history and previous laboratory reports of patients. Deoxyribonucleic acid (DNA) was extracted, and C. pneumonia DNA was amplified and detected using PCR assay.

Results:

The age of the patients in the study group was from 18 to 50 years, and the male to female ratio was 5:1. Only oneout of the 30 coronary tissue samples had positive PCR for C. pneumoniae (3.3%), while it was negative for patients in the control group.

Conclusions:

This study showed that C. pneumoniae infection is not strongly associated with coronary artery atherosclerosis in Northeast of Iran.

Association of plasma circulatory markers, Chlamydia pneumoniae, and high sensitive C-reactive protein in coronary artery disease patients of India

Plasma inflammatory markers have been shown to be predictors for cardiovascular risk, however, there is no study where the levels of plasma circulatory markers have been evaluated in coronary artery disease patients (CAD pts) positive for C. pneumoniae IgA and high sensitive C-reactive protein (hsCRP) which may help in better understanding of disease pathogenesis. A total of 192 patients and 192 controls attending the Cardiology Outpatient Department of Safdarjung Hospital were enrolled. The levels of plasma circulatory inflammatory markers were evaluated by ELISA. The levels of circulatory plasma markers (IL-4, IL-8, IL-13, ICAM-1, and VCAM-1) were significantly higher, whereas, levels of IL-10 and IFN-γ were significantly lower in CAD pts compared to healthy controls. The levels of IL-4, IL-8, and ICAM-1 (P = .007, .015, and .048) were significantly higher, however, IL-10 and IFN-γ were significantly lower (P < .001, < .001) in C. pneumoniae IgA positive CAD pts. The levels of IL-4, IL-8, IL-13, ICAM-1, and VCAM-1 were higher but not significant and levels of IL-10 and IFN-γ were significantly (P < .001, < .001) lower in hsCRP positive CAD pts. Our study suggested that circulatory cytokines, namely, IL-4, IL-8, and adhesive molecules like ICAM-1 were enhanced after infection with C. pneumoniae whereas in contrast to this IL-10 and IFN-λ were lowered. Suggesting the important role of these cytokines in progression of CAD.