Abstract 14279: Apolipoprotein B Bound To Erythrocytes: A Novel Anti-atherogenic Lipid Transport Pathway
Background and aim: Apolipoprotein (apo) B containing lipoproteins are closely linked to atherogenesis. These lipoproteins are transported in plasma and can bind to blood leukocytes. Our aim was to investigate whether apoB is also present on erythrocytes and if there is a relationship with the presence of atherosclerosis.
Methods: Subjects with coronary artery disease (CAD+, n=39) and without (CAD- n=120), based on coronary angiography or with a history of cardiovascular disease, were included. Anthropometric parameters were determined and blood was collected. Erythrocyte-bound apoB was measured by flowcytometry with polyclonal anti-apoB antibodies and a fluorescent (FITC) labelled secondary antibody. Intima media thickness (IMT) measurements were carried out using B-mode ultrasound at three different projections of the far wall of each carotid artery and the mean of these measurements was used.
Results: In all but nine subjects (4 CAD- and 5 CAD+) apoB was detected on freshly isolated erythrocytes (range: 0.1 to 5.5 au; mean±SEM 0.86±0.09 au). Erythrocyte-bound apoB was lower in CAD+ (0.62±0.09 au; mean±SEM) compared to CAD- (1.18±0.10 au; P<0.001). The effect of ery-apoB binding on the presence of CAD was modified by age (adjusted-OR: 1.102, 95%CI (1.039-1.168); P<0.001). Carotid IMT was increased in CAD+ subjects (0.77±0.13mm; mean±SD) compared to CAD- (0.56±0.14 mm; P<0.001). A significant negative correlation was found between erythrocyte bound-apoB and IMT (Spearman's rho: -0.291; P=0.002). There was no association with plasma apoB (r:0.10). Significant negative associations were found with glucose (r:-0.21; P=0.03), diastolic blood pressure (r:-0.21; P=0.03) and positive associations with HDL-C (r:0.20; P=0.04) and apoAI (r:0.20; P:0.03).
Conclusion: ApoB can be detected on erythrocytes. Subjects with CAD have lower ery-apoB. High apoB bound to erythrocytes may be protective against atherosclerosis, and may reflect an alternative bloodcell-mediated lipoprotein transport system in humans in which these lipoproteins are less likely to interact with the endothelium.
- © 2010 by American Heart Association, Inc.