Increased CD36 expression on circulating monocytes during HIV infection.
BACKGROUND: Metabolic alterations and abnormalities of fat distribution are common findings in antiretroviral-treated HIV-1-infected patients. CD36 is a multifunctional receptor with a wide tissue distribution that plays a crucial role in the cellular uptake and metabolism of lipids. OBJECTIVES: To define the level of CD36 expression on circulating monocytes from HIV-1-infected patients and healthy controls (HCs) and to correlate CD36 expression levels with metabolic and immunovirologic parameters. METHODS: CD36 expression on peripheral blood monocytes was measured by means of flow cytometry in 165 HIV-1-infected patients and in 35 HCs. Statistical analysis was performed by means of univariate and multivariate analysis of variance models. RESULTS: CD36 expression was significantly higher in HIV-1-infected patients compared with HCs (P < 0.0001). HIV-1 infection was the only variable associated with CD36 expression on multivariate analysis, whereas no correlation was found between CD36 level and age, sex, body mass index, lipid serum levels, HIV RNA levels, time on antiretroviral therapy, or kind of antiretroviral regimen. CONCLUSIONS: HIV-1 infection is associated with increased expression of CD36 on circulating monocytes, and antiretroviral drugs play only a minor role in the complex homeostasis of this receptor. Given its role in the cellular uptake and accumulation of lipids, CD36 increased levels on monocytes could represent a proatherogenic condition in HIV-infected patients.