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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, RESULTS. Meshes: Aged, Aged, 80 and over, Biomarkers, C-Reactive Protein, Carotid Arteries, Carotid Artery Diseases, Chlamydophila Infections, Chlamydophila pneumoniae, Endarterectomy, Carotid, Female, Humans, Immunohistochemistry, Interleukin-6, Male, Middle Aged, Reverse Transcriptase Polymerase Chain Reaction, Risk Factors, Up-Regulation, Vasculitis.
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Is chlamydia pneumoniae burden in carotid arteries associated with upregulation of plaque interleukin-6 and elevated C-reactive protein in serum? Context: Chlamydia pneumoniae (Cpn) infection of vascular smooth muscle cells increases interleukin-6 (IL-6) secretion in vitro. In vivo, IL-6 stimulates liver C-reactive protein (CRP) production. Because serum levels of IL-6 and CRP are independent risk factors for stroke and myocardial infarction (MI), we investigated whether Cpn burden in carotid plaques might provide a link between plaque IL-6 expression and elevated serum levels of IL-6 and CRP. Consecutive patients undergoing elective carotid endarterectomy were studied. Serum levels of CRP and IL-6 were measured before surgery. Immunohistochemistry and real-time quantitative (k)RT-PCR were used to detect Cpn and the expression of IL-6 within carotid plaques. Cpn mRNA was present in 19 (37%) of 51 patients, suggesting viable infections. These patients had evidence for infection by PCR and immunohistochemistry. The Cpn burden, measured by real-time quantitative (k)-PCR using the number of organisms normalized against the number of eukaryotic cells in the tissue, was associated with plaque expression of IL-6 (Spearman R=0.55; P<0.0001), which was associated with serum levels of IL-6 (R=0.56; P<0.0001) and CRP (R=0.80; P<0.0001).
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IL-6 secretion in atherosclerotic plaques infected with Cpn could explain elevated serum inflammatory markers in individuals at risk for stroke and MI. Final Decision: yes