title: Clinical relevance of nitric oxide metabolites and nitrative stress in thrombotic primary antiphospholipid syndrome.
abstract: OBJECTIVE
  To assess the role of nitrite (NO(2)(-)), nitrate (NO(3)(-)), and nitrative stress in thrombotic primary antiphospholipid syndrome (PAPS).
  
  
  METHODS
  We investigated 46 patients with PAPS: 21 asymptomatic but persistent carriers of antiphospholipid antibodies (PCaPL), 38 patients with inherited thrombophilia (IT), 33 patients with systemic lupus erythematosus (SLE), and 29 healthy controls (CTR). IgG anticardiolipin (aCL), IgG anti-beta(2)-glycoprotein I (anti-ß(2)-GPI), IgG anti-high density lipoprotein (aHDL), IgG anti-apolipoprotein A-I (aApoA-I), crude nitrotyrosine (NT) (an indicator of nitrative stress), and high sensitivity C-reactive protein (CRP) were measured by immunoassays. Plasma nitrite (NO(2)(-)), nitrate (NO(3)(-)), and total antioxidant capacity (TAC) were measured by colorimetric spectroscopic assays.
  
  
  RESULTS
  Average plasma NO(2)(-) was lower in PAPS, PCaPL, and IT (p < 0.0001); average NO(3)(-) was highest in SLE (p < 0.0001), whereas average NT was higher in PAPS and SLE (p = 0.01). In thrombotic PAPS, IgG aCL titer and number of vascular occlusions negatively predicted NO(2)(-) (p = 0.03 and p = 0.001, respectively), whereas arterial occlusions and smoking positively predicted NO(3)(-) (p = 0.05 and p = 0.005), and CRP positively predicted NT (p = 0.004). In the PCaPL group IgG aCL negatively predicted NO(3)(-) (p = 0.03). In the SLE group IgG aCL negatively predicted NO(2)(-) (p = 0.03) and NO(3)(-) (p = 0.02).
  
  
  CONCLUSIONS
  PAPS is characterized by decreased NO(2)(-) in relation to type and number of vascular occlusions and to aPL titers. Nitrative stress and low grade inflammation are linked phenomena in PAPS and may have implications for thrombosis and atherosclerosis.
authors.affiliation: Department of Rheumatology, Airedale General Hospital, Steeton, UK. paxmes@aol.com
authors.forename: Paul R J
authors.initials: PR
authors.lastname: Ames
authors.forename: Joana R
authors.initials: JR
authors.lastname: Batuca
authors.forename: Antonio
authors.initials: A
authors.lastname: Ciampa
authors.forename: Luigi
authors.initials: L
authors.lastname: Iannaccone
authors.forename: Jose
authors.initials: J
authors.lastname: Delgado Alves
mesh_terms: D000328:Adult; D017152:Antibodies, Antiphospholipid / Q000097:blood; D016736:Antiphospholipid Syndrome / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism*; D013312:Stress, Physiological; D013927:Thrombosis / Q000097:blood* / Q000209:etiology
chemical_list: D017152:Antibodies, Antiphospholipid; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide