18FDG PET-CT imaging detects arterial inflammation and early atherosclerosis in HIV-infected adults with cardiovascular disease risk factors

Abstract

BackgroundPersistent vascular inflammation has been implicated as an important cause for a higher prevalence of cardiovascular disease (CVD) in HIV-infected adults. In several populations at high risk for CVD, vascular 18Fluorodeoxyglucose (18FDG) uptake quantified using 3D-positron emission-computed tomography (PET-CT) has been used as a molecular level biomarker for the presence of metabolically active proinflammatory macrophages in rupture-prone early atherosclerotic plaques. We hypothesized that 18FDG PET-CT imaging would detect arterial inflammation and early atherosclerosis in HIV-infected adults with modest CVD risk.MethodsWe studied 9 HIV-infected participants with fully suppressed HIV viremia on antiretroviral therapy (8 men, median age 52 yrs, median BMI 29 kg/m2, median CD4 count 655 cells/μL, 33% current smokers) and 5 HIV-negative participants (4 men, median age 44 yrs, median BMI 25 kg/m2, no current smokers). Mean Framingham Risk Scores were higher for HIV-infected persons (9% vs. 2%, p < 0.01). 18FDG (370 MBq) was administered intravenously. 3D-PET-CT images were obtained 3.5 hrs later. 18FDG uptake into both carotid arteries and the aorta was compared between the two groups.ResultsRight and left carotid 18FDG uptake was greater (P < 0.03) in the HIV group (1.77 ±0.26, 1.33 ±0.09 target to background ratio (TBR)) than the control group (1.05 ± 0.10, 1.03 ± 0.05 TBR). 18FDG uptake in the aorta was greater in HIV (1.50 ±0.16 TBR) vs control group (1.24 ± 0.05 TBR), but did not reach statistical significance (P = 0.18).ConclusionsCarotid artery 18FDG PET-CT imaging detected differences in vascular inflammation and early atherosclerosis between HIV-infected adults with CVD risk factors and healthy HIV-seronegative controls. These findings confirm the utility of this molecular level imaging approach for detecting and quantifying glucose uptake into inflammatory macrophages present in metabolically active, rupture-prone atherosclerotic plaques in HIV infected adults; a population with increased CVD risk.

Arterial Disease in Patients With Human Immunodeficiency Virus Infection

“…In a proof of concept study, 9 HIV-infected individuals with suppressed viremia on ART were compared to 5 HIV-negative individuals and were shown to have higher 18 FDG uptake in the carotid arteries (77). In another cross-sectional study, 27 HIV-infected individuals were compared to two non-HIV-infected control groups, one matched for age, sex, Framingham risk score, and without atherosclerotic disease, the other matched on gender but with known atherosclerotic disease (78).…”

Inflammation and Fibrosis in HIV

“…10, 11 Recent imaging studies have added to our understanding of the relationship between immune activation and atherosclerotic inflammation in HIV. In studies that employed FDG-PET/CT, individuals with HIV have been shown to have higher levels of atherosclerotic inflammation compared to non-infected controls 12, 13 . One such study showed that the atherosclerotic inflammation correlates with markers of monocyte activation.…”

Effect of AIDS on Women Who Have Sex-Determined Health Issues

“…Yarasheski et al 30 have detected differences in vascular inflammation and early atherosclerosis between HIV-infected adults with CVD risk factors and healthy HIV-seronegative controls with 18 F-FDG-PET/CT imaging. These findings confirm the utility of the molecular-level imaging approach to detecting and quantifying glucose uptake in inflammatory macrophages present in metabolically active, rupture-prone atherosclerotic plaques in HIV-infected adults, a population with increased CVD risk.…”