title: The evaluation of autoantibodies against oxidatively modified low-density lipoprotein (LDL), susceptibility of LDL to oxidation, serum lipids and lipid hydroperoxide levels, total antioxidant status, antioxidant enzyme activities, and endothelial dysfunction in patients with Behçet's disease.
abstract: OBJECTIVE
  Behçet's disease is a multisystem disorder characterized by a chronic inflammation including acute attacks and remission periods. Decreased enzyme activity of the antioxidant system and increased levels of free radicals may have important roles in the damage of tissues observed in the disease period. In addition, the atherogenic tendency of serum lipid, lipoproteins, lipid peroxidation levels and endothelial dysfunction accompany the above mentioned findings. As a consequence of these events, different degrees of low density lipoprotein (LDL) oxidation occur in vivo, and then autoantibodies against oxidized-LDL(AuAb-oxLDL) are produced.
  
  
  METHODS
  Lipids, lipoproteins, lipid hydroperoxide, AuAb-oxLDL, total antioxidant status (TAS), serum-soluble intercellular adhesion molecule-1 (sICAM-1), plasminogen activator inhibitor 1 (PAI-1) levels in serum, the activities of antioxidant enzymes including glutathione peroxidase (GSH-Px), glutathione reductase (GR), superoxide dismutase (SOD), and catalase (CAT) in erythrocytes and plasma, were determined in 25 patients with Behçet's disease and in 25 healthy volunteers. Also, susceptibility to copper-induced in vitro oxidation of LDL by using lag time, a measure of resistance to oxidation, oxidation rate and extent of oxidation, a measure of diene production in both groups, was studied.
  
  
  RESULTS
  It was observed that lipid hydroperoxide and AuAb-oxLDL levels in patients with Behçet's disease were significantly higher, but erythrocyte SOD, CAT, plasma GSH-Px activities, and TAS were significantly lower than those in healthy subjects. Susceptibility of LDL to oxidation in the patients was found to be increased. Total cholesterol, LDL-C and apo B levels and acute phase reactants were significantly higher, but HDL-C and apo AI levels were significantly lower, in patients when compared to healthy subjects. The levels of AuAb-oxLDL in patients were found to correlate with TAS, total cholesterol, LDL-C, lipid hydroperoxide and erythrocyte SOD activities (r = -0.62, p < 0.01; r = 0.64, p < 0.01; r = 0.55, p < 0.01; r = 0.81, p < 0.01; r = -0.63, p < 0.01, respectively). In addition, lipid hydroperoxide levels were found to correlate with total cholesterol, LDL-C and erythrocyte SOD activities (r = 0.45, p < 0.05; r = 0.45, p < 0.05; r = -0.46, p < 0.05, respectively). PAI-1 and sICAM-1 were found to be increased in the patients and correlated with AuAb-oxLDL and lipid hydroperoxide levels (r = 0.56, p < 0.01; r = 0.67, p < 0.01 and r = 0.59, p < 0.01; r = 0.61, p < 0.01, respectively).
  
  
  CONCLUSIONS
  It was concluded that the observed increase of lipid, lipoproteins, lipid hydroperoxide, susceptibility of LDL to oxidation, autoantibodies against ox-LDL levels and decrease of antioxidant enzyme activities and total antioxidant status and increased secretion of endothelial derivated peptides including sICAM and PAI-1, and their interactions may indicate that there is a tendency to atherothrombotic events in patients with Behçet's disease.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Karadeniz Technical University, 61080, Trabzon, Turkey. aorem64@yahoo.com
authors.forename: Asim
authors.initials: A
authors.lastname: Orem
authors.forename: Y Emre
authors.initials: YE
authors.lastname: Yandi
authors.forename: Birgül
authors.initials: B
authors.lastname: Vanizor
authors.forename: Gülseren
authors.initials: G
authors.lastname: Cimşit
authors.forename: Hüseyin Avni
authors.initials: HA
authors.lastname: Uydu
authors.forename: Meltem
authors.initials: M
authors.lastname: Malkoç
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D001323:Autoantibodies / Q000276:immunology*; D001528:Behcet Syndrome / Q000097:blood / Q000276:immunology* / Q000378:metabolism* / Q000503:physiopathology; D002374:Catalase / Q000378:metabolism; D004727:Endothelium / Q000503:physiopathology*; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006801:Humans; D008054:Lipid Peroxides / Q000097:blood*; D008055:Lipids / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood / Q000276:immunology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D001323:Autoantibodies; D008054:Lipid Peroxides; D008055:Lipids; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase