Plasma distribution of apoA-IV in patients with coronary artery disease and healthy controls.
Recent studies showed lower apolipoprotein A-IV (apoA-IV) plasma concentrations in patients with coronary artery disease (CAD). The actual distribution of the antiatherogenic apoA-IV in human plasma, however, is discussed controversially and it was never investigated in CAD patients. We therefore developed a gentle technique to separate the various apoA-IV-containing plasma fractions. Using a combination of precipitation of all lipoproteins with 40% phosphotungstic acid and 4 M MgCl2, as well as immunoprecipitation of all apoA-I-containing particles with an anti-apoA-I antibody, we obtained three fractions of apoA-IV: lipid-free apoA-IV (about 4% of total apoA-IV), apoA-IV associated with apoA-I (LpA-I:A-IV, 12%), and apoA-I-unbound but lipoprotein-containing apoA-IV (LpA-IV, 84%). We compared these three apoA-IV fractions between 52 patients with a history of CAD and 52 age- and sex-matched healthy controls. Patients had significantly lower apoA-IV levels when compared to controls (10.28 +/- 3.67 mg/dl vs. 11.85 +/- 2.82 mg/dl, P = 0.029), but no major differences for the three plasma apoA-IV fractions. We conclude that our gentle separation method reveals a different distribution of apoA-IV than in many earlier studies. No major differences exist in the apoA-IV plasma distribution pattern between CAD patients and controls. Therefore, the antiatherogenic effect of apoA-IV has to be explained by other functional properties of apoA-IV (e.g., the antioxidative characteristics).
Ezeh
Benjie
B
Institute of Medical Biology and Human Genetics, University of Innsbruck, Schöpfstr 41, A-6020, Innsbruck, Austria.
Haiman
Marina
M
Alber
Hannes F
HF
Kunz
Birgit
B
Paulweber
Bernhard
B
Lingenhel
Arno
A
Kraft
Hans-Georg
HG
Weidinger
Franz
F
Pachinger
Otmar
O
Dieplinger
Hans
H
Kronenberg
Florian
F
D000328:Adult; D001054:Apolipoproteins A / Q000097:blood* / Q000302:isolation & purification; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000097:blood* / Q000453:epidemiology; D005260:Female; D006262:Health; D006801:Humans; D015151:Immunoblotting; D008297:Male; D008875:Middle Aged
D001054:Apolipoproteins A; C022205:apolipoprotein A-IV