Intraplaque hemorrhage in carotid atherosclerotic plaques is associated with a local increase in inflammatory cytokines

Abstract Background One of the main features of vulnerability in atherosclerotic carotid plaques is intraplaque hemorrhage (IPH), which is related to a higher incidence of cerebrovascular events in patients with carotid artery disease. Additionally, inflammation plays a pivotal role in the progression of atherosclerotic disease. Purpose We aimed to determine plasma and tissue levels of inflammatory cytokines in patients with carotid artery disease hypothesizing that plaques with IPH are characterized by the presence of a more inflamed environment. Methods We retrospectively enrolled 104 consecutive patients undergoing carotid endarterectomy (CEA) with symptomatic (ischemic stroke, TIA, amaurosis fugax) or asymptomatic ipsilateral carotid artery disease. Plasma and carotid plaque specimens were collected at CEA. The tissue samples were stained with H&E to identify IPH and classified as specimens with and without IPH. Frozen homogenates of both plasma and tissue were analyzed using a customized 10-plex Luminex assay to determine the levels of inflammatory cytokines such as MCP-1/CCL2, IL-8/CXCL8, IFN-gamma, IL-10, IL-1beta/IL-1F2, IL-6, PDGF-AA, PDGF-AB/BB, TNF-alpha, and VEGF. Results IPH was identified in 53 patients (51.0 %). Cytokine levels in plasma and tissue from patients with and without IPH are reported in Table 1. In the univariate logistic regression MCP-1/CCL2, IL-8/CXCL8, IFN-gamma, IL-10, IL6, PDGF-AA, and PDGF-AB/BB were associated with IPH (Table 2). In the multivariate logistic regression, IL-6 was an independent predictor of IPH (HR 1.026 [95% CI 1.005-1.047]; p=0.014) after adjusting for cardiovascular risk factors such as age, BMI, sex, hypertension, diabetes mellitus, hyperlipidemia, ipsilateral carotid stenosis %. Conclusions Carotid plaques with IPH have an elevated inflammatory burden, potentially impacting adverse outcomes in this patient cohort. The local inflammatory cytokines in carotid plaques with IPH might serve as biomarkers and therapeutic targets in patients with carotid artery disease.