title: Erythrocyte-associated apolipoprotein B and its relationship with clinical and subclinical atherosclerosis.
abstract: BACKGROUND
  Apolipoprotein (apo) B-containing lipoproteins are closely linked to atherogenesis. These lipoproteins are transported in plasma and are also associated with blood leucocytes. Our aim was to investigate whether apoB-containing lipoproteins are also present on the surface of erythrocytes and investigate the relationship with the presence of atherosclerosis in a cross-sectional study.
  
  
  METHODS
  Erythrocyte-bound apoB (ery-apoB) was measured by flowcytometry in subjects with (CAD+) and without coronary artery disease (CAD-), based on coronary angiography or on a history of cardiovascular disease. Intima media thickness (IMT) measurements were carried out using B-mode ultrasound. The relationship between ery-apoB and clinical and subclinical atherosclerosis was evaluated with binary logistic regression.
  
  
  RESULTS
  A total of 166 subjects were included (40 CAD+ and 126 CAD-). ApoB was detected on freshly isolated erythrocytes (range: 0·1-5·5 au; mean ± SEM 0·86 ± 0·09 au) in all but nine subjects (four CAD+ and five CAD-). Ery-apoB was lower in CAD+ (0·62 ± 0·09 au) compared to CAD- (1·18 ± 0·10 au; P < 0·001). Higher ery-apoB was associated with a lower risk of CAD (adjusted OR: 0·003 (95% CI: 0·001-0·08; P < 0·001), but the protective effect was diminished with increasing age (adjusted OR: 1·10 (95% CI: 1·04-1·16; P < 0·001). IMT was increased in CAD+ subjects (0·77 ± 0·13 mm) compared to CAD- (0·57 ± 0·14 mm; P < 0·001). A significant negative association was found between ery-apoB and IMT (β = -0·214: 95% CI -0·284 to -0·145; P < 0·001). There was no association between ery-apoB and plasma apoB (Pearson's r = -0·45; P = 0·57).
  
  
  CONCLUSIONS
  Human erythrocytes carry apoB-containing lipoproteins. Subjects with atherosclerosis have lower ery-apoB. High ery-apoB may be protective against atherosclerosis and may reflect an alternative blood cell-mediated lipoprotein transport system in the circulation, in which these lipoproteins less likely interact with the endothelium.
authors.affiliation: Department of Internal Medicine, Sint Franciscus Gasthuis Rotterdam, Rotterdam, The Netherlands.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Bovenberg
authors.forename: Boudewijn
authors.initials: B
authors.lastname: Klop
authors.forename: Arash
authors.initials: A
authors.lastname: Alipour
authors.forename: Sergio
authors.initials: S
authors.lastname: Martinez-Hervas
authors.forename: Andrew
authors.initials: A
authors.lastname: Westzaan
authors.forename: Gert-Jan M
authors.initials: GJ
authors.lastname: van de Geijn
authors.forename: Hans W J
authors.initials: HW
authors.lastname: Janssen
authors.forename: Tjin
authors.initials: T
authors.lastname: Njo
authors.forename: Erwin
authors.initials: E
authors.lastname: Birnie
authors.forename: Rob
authors.initials: R
authors.lastname: van Mechelen
authors.forename: Arie P
authors.initials: AP
authors.lastname: Rietveld
authors.forename: Jan Willem F
authors.initials: JW
authors.lastname: Elte
authors.forename: Manuel
authors.initials: M
authors.lastname: Castro Cabezas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001055:Apolipoproteins B / Q000097:blood*; D050197:Atherosclerosis / Q000097:blood* / Q000000981:diagnostic imaging; D059168:Carotid Intima-Media Thickness; D017023:Coronary Angiography / Q000379:methods; D003430:Cross-Sectional Studies; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D001055:Apolipoproteins B