title: Asymmetric dimethylarginine in exhaled breath condensate and serum of children with asthma.
abstract: BACKGROUND
  Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor and uncoupler of nitric oxide synthase. By promoting the formation of peroxynitrite, ADMA is believed to contribute to several aspects of asthma pathogenesis (ie, airway inflammation, oxidative stress, bronchial hyperresponsiveness, and collagen deposition). The aim of the present study was to compare this mediator in healthy children and children with asthma using the completely noninvasive exhaled breath condensate (EBC) technique.
  
  
  METHODS
  We recruited 77 children with asthma (5-16 years of age) and 65 healthy children (5-15 years of age) who underwent EBC collection and spirometry. Serum ADMA levels and fractional exhaled nitric oxide levels were measured on the same day in a subgroup of children with asthma. EBC was collected using the Turbo-Deccs (Medivac). ADMA levels were measured using the ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) technique.
  
  
  RESULTS
  ADMA could be detected in the EBC of 71 subjects with asthma and 64 healthy subjects. ADMA levels in the EBC of children with asthma were significantly higher than in the healthy control subjects (median, 0.12 [interquartile range, 0.05-0.3] vs 0.07 [0.05-0.12]; P = .017), whereas no difference emerged between the children with asthma who were or were not receiving inhaled steroid treatment. No correlation was found between serum and EBC ADMA levels (P &gt; .5).
  
  
  CONCLUSIONS
  We measured ADMA in EBC by UPLC-MS/MS, a reference analytical technique. Higher ADMA levels were found in children with asthma, supporting a role for this mediator in asthma pathogenesis. This oxidative stress-related mediator also seems to be scarcely affected by steroid therapy. We speculate that ADMA might be a target for new therapeutic strategies designed to control oxidative stress in asthma.
authors: Women's and Children's Health Department, University of Padova, Padova.
authors: Silvia
authors: S
authors: Carraro
authors: Women's and Children's Health Department, University of Padova, Padova.
authors: Giuseppe
authors: G
authors: Giordano
authors: Department of Pediatrics, University of Verona, Verona.
authors: Giorgio
authors: G
authors: Piacentini
authors: Paediatric Asthma Centre, Misurina Pio XII Institute, Belluno, Italy.
authors: Ahmad
authors: A
authors: Kantar
authors: Department of Pediatrics, University of Verona, Verona.
authors: Serena
authors: S
authors: Moser
authors: Women's and Children's Health Department, University of Padova, Padova.
authors: Laura
authors: L
authors: Cesca
authors: Women's and Children's Health Department, University of Padova, Padova.
authors: Mariangela
authors: M
authors: Berardi
authors: Women's and Children's Health Department, University of Padova, Padova.
authors: Iole M
authors: IM
authors: Di Gangi
authors: Women's and Children's Health Department, University of Padova, Padova. Electronic address: baraldi@pediatria.unipd.it.
authors: Eugenio
authors: E
authors: Baraldi
mesh_terms: D000293:Adolescent; D001120:Arginine / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism; D001249:Asthma / Q000097:blood / Q000378:metabolism*; D001944:Breath Tests; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003430:Cross-Sectional Studies; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress; D013147:Spirometry; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D009569:Nitric Oxide; C018524:N,N-dimethylarginine; D001120:Arginine