title: Assessment of homocysteine, neopterin and nitric oxide levels in Behçet's disease.
abstract: BACKGROUND
  Behçet's disease is a multisystemic immunoinflammatory disease with a wide variety of clinical manifestations, whereas recurrent aphthous stomatitis is a local oral disease. The aim of this study was to examine the distribution of homocysteine levels in patients with active Behçet's disease, possible association of homocysteine with nitric oxide and neopterin levels, and to characterize the differences between patients with Behçet's disease and those with recurrent aphthous stomatitis in terms of these parameters compared with healthy controls.
  
  
  METHODS
  A total of 23 patients with active Behçet's disease, 25 patients with recurrent aphthous stomatitis as positive controls, and 21 healthy subjects were included in this study. Serum homocysteine and neopterin levels were measured flourimetrically by HPLC. Serum nitric oxide production was assayed by measuring total nitrite levels with Griess reagent.
  
  
  RESULTS
  Significantly higher homocysteine (12.9+/-3.3 micromol/L) and lower nitric oxide (41.5+/-10.9 micromol/L) and neopterin (6.4+/-1.0 nmol/L) levels were observed in patients with Behçet's disease compared with healthy controls (10.7+/-2.0 micromol/L, 49.7+/-16.2 micromol/L, 8.7+/-2.2 nmol/L, respectively) (p<0.03 for neopterin, p<0.04 for homocysteine and nitric oxide). However, homocysteine, nitric oxide, biopterin and neopterin levels and the neopterin/biopterin ratio for recurrent aphthous stomatitis patients were not significantly different compared to healthy controls. A significant positive correlation was observed between serum homocysteine and serum neopterin/biopterin ratio in patients with Behçet's disease (r=0.975, p<0.005).
  
  
  CONCLUSIONS
  In contrast to recurrent aphthous stomatitis, there is a higher prevalence of hyperhomocysteinemia in Behcet's disease. Homocysteine may have deleterious effects on the pathology of Behcet's disease by decreasing nitric oxide levels and interfering with the immune system.
authors.affiliation: Department of Biochemistry, Faculty of Pharmacy, Gazi University, Ankara, Turkey. yesim@gazi.edu.tr
authors.forename: Yeşim
authors.initials: Y
authors.lastname: Ozkan
authors.forename: Sevgi
authors.initials: S
authors.lastname: Yardim-Akaydin
authors.forename: Aylin
authors.initials: A
authors.lastname: Sepici
authors.forename: Başak
authors.initials: B
authors.lastname: Engin
authors.forename: Vesile
authors.initials: V
authors.lastname: Sepici
authors.forename: Bolkan
authors.initials: B
authors.lastname: Simşek
mesh_terms: D000328:Adult; D001528:Behcet Syndrome / Q000097:blood* / Q000150:complications; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000150:complications; D008297:Male; D019798:Neopterin / Q000097:blood*; D009569:Nitric Oxide / Q000097:blood*; D011237:Predictive Value of Tests; D012008:Recurrence; D013281:Stomatitis, Aphthous / Q000097:blood / Q000150:complications
chemical_list: D006710:Homocysteine; D009569:Nitric Oxide; D019798:Neopterin