Viral Agents and Systemic Levels of Inflammatory Cytokines in Vulnerable and Stable Atherosclerotic Carotid Plaques

Abstract

Background: To investigate the presence of genetic material of viral agents and the serum level of inflammatory cytokines in patients submitted to carotid endarterectomy having vulnerable versus stable atherosclerotic plaques.

Methods: Data of patients consecutively submitted to carotid endarterectomy for a significant stenosis from July 2019 to December 2019 were prospectively collected. The genetic material of Epstein-Barr (EBV), CitoMegalo (CMV), Herpes Simplex (HSV), Varicella-Zoster (VZV) and Influenza (IV) Viruses was searched in the patient's plaques, both in the "mid" of the plaque and in an adjacent lateral portion of no-plaque area. The serum levels of TNF-α, IL-1β, IL-6, IL10 and CCL5 were determined. The obtained results were then correlated to the histologic vulnerability of the removed carotid plaque. P values < 0.05 were considered statistically significant.

Results: Data of 50 patients were analyzed. A vulnerable plaque was found in 31 patients (62%). The genome of CMV, HSV, VZV and IV was not found in any of the vascular samples, while the EBV genome was found in the "mid" of 2 vulnerable plaques, but not in their respective control area. Eighty-two percent of patients who did not receive anti-IV vaccination (23/28) had vulnerable carotid plaque, compared with 36% of vaccinated patients (8/22, P = 0.001). Serum levels of TNF-α and IL-6 were higher in patients with a vulnerable plaque compared to patients with a stable plaque (73.6 ± 238.2 vs. 3.9 ± 13.1 pg/ml, P= 0.01, and 45.9 ± 103.6 vs. 10.1 ± 25.3 pg/ml, P= 0.01, respectively), independent of comorbidities, viral exposure or flu vaccination.

Conclusions: The EBV genome was found in the "core" of 2 vulnerable carotid plaques, but not in their respective adjacent control. Influenza vaccination was associated with a lower incidence of carotid plaque vulnerability. Serum levels of TNF-α and IL-6 were higher in patients with a vulnerable plaque compared to patients with a stable plaque.