The presence of some cytokines and Chlamydia pneumoniae in the atherosclerotic carotid plaque in patients with carotid artery stenosis

Background: Over the last few years the role of microorganisms in the pathogenesis of atherosclerosis has been widely discussed. Chlamydia pneumoniae activates immune cells to produce cytokines that are responsible for the formation of atheromatous carotid lesions. Material and methods: The study was carried out at the Department of Vascular, General and Transplantation Surgery, Wroclaw Medical University, in 2002-2003, on 100 consecutive symptomatic patients with internal carotid stenosis, who underwent an endarterectomy procedure. Each patient had their carotid artery sampled in order to find C. pneumoniae DNA using the nested PCR method and some cytokines (TGF-beta, VEGF, FGF, TNF-alpha) using immunohistochemical examination. The control group consisted of 20 young organ donors who had been diagnosed with brain death and who had their healthy carotid artery harvested. Analogous genetic and immunohistochemical tests were performed. Results: We did not confirm the presence of either cytokines or C. pneumoniae in the healthy carotid arteries. The presence of FGF was probably due to intima fibroblast activity, which is responsible for elastin and collagen synthesis for the extracellular matrix. C. pneumoniae was discovered in 68% of patients with carotid plaques. Three cytokines (TGF-beta, FGF, TNF-alpha) were detected in atherosclerotic internal carotid arteries as well. Conclusion: Chronic infection by C. pneumoniae may exacerbate carotid plaque development and may lead to its destabilization.