Short Communication: Carotid Artery Plaque Burden in HIV Is Associated with Soluble Mediators and Monocytes

Abstract

Maximum carotid plaque thickness (MCPT) measures the largest plaque thickness in the carotid artery and reflects atherosclerosis plaque burden. MCPT may be a better predictor of cardiovascular disease than carotid artery intima-media thickness (cIMT) because it identifies potential unstable arterial atherosclerosis plaques. We assessed the relationships of monocyte and T cell populations and plasma soluble mediators with MCPT measures. We performed a cross-sectional and small follow-up analysis in people living with HIV (PLWH) aged >40 years on stable antiretroviral therapy (ART) >6 months. MCPT was acquired by high-resolution B-mode ultrasound. Existing monocyte subsets and T cell activation frequencies were determined by flow cytometry and plasma mediators of inflammation and apolipoproteins were measured by Luminex assay. One hundred twenty-five ART-treated PLWH, 88% male, 55% Caucasian, with a median age of 51 years, median CD4 count of 477 cells/μL (Q1: 325, Q3: 612), 84% undetectable plasma HIV RNA (<50 copies/mL). Twenty-five PLWH had detectable carotid plaque. MCPT correlated with monocyte chemoattractant protein-1 (MCP-1; r = 0.487, p = .016), tumor necrosis factor-α (TNF-α; r = 0.474 p = .019), soluble vascular cell adhesion molecule-1 (sVCAM-1; r = 0.472, p = .020), apolipoprotein B6 (ApoB6; r = -0.473, p = .019), and interleukin-6 (IL-6; r = 0.455, p = .025). In a multivariable regression model, MCP-1, TNF-α, and sVCAM-1 remained significant after adjustment for age. Carotid plaque burden was associated with increased inflammatory, monocyte, and endothelial measures, including MCP-1, TNF-α, and sVCAM-1 levels. Further investigation on the evolution or severity of plaque burden in this population is warranted.

Keywords: maximum carotid plaque thickness; monocyte subsets; soluble mediators.