Chlamydia pneumoniae-Mediated Inflammation in Atherosclerosis: A Meta-Analysis

Abstract

Several studies have attempted to relate theC. pneumoniae-mediated inflammatory state with atherosclerotic cardiovascular diseases, providing inconsistent results. Therefore, we performed a meta-analysis to clarify whetherC. pneumoniaemay contribute to the pathogenesis of atherosclerosis by enhancing inflammation. 12 case-control, 6 cross-sectional, and 7 prospective studies with a total of 10,176 patients have been included in this meta-analysis. Odds Ratio (OR) with a 95% confidence interval was used to assess the seroprevalence ofC. pneumoniaeand differences between levels of inflammatory markers were assessed by standard mean differences. Publication bias was performed to ensure the statistical power. hsCRP, fibrinogen, interleukin- (IL-) 6, TNF-α, and IFN-γshowed a significant increase in patients with atherosclerosis compared to healthy controls (P<0.05), along with a higher seroprevalence ofC. pneumoniae(OR of 3.11, 95% CI: 2.88–3.36,P<0.001). More interestingly, hsCRP, IL-6, and fibrinogen levels were significantly higher inC. pneumoniaeIgA seropositive compared to seronegative atherosclerotic patients (P<0.0001). In conclusion, the present meta-analysis suggests thatC. pneumoniaeinfection may contribute to atherosclerotic cardiovascular diseases by enhancing the inflammatory state, and, in particular, seropositivity toC. pneumoniaeIgA, together with hsCRP, fibrinogen, and IL-6, may be predictive of atherosclerotic cardiovascular risk.