title: Fractional Exhaled Nitric Oxide: A Potential Biomarker in Allergic Rhinitis?
abstract: BACKGROUND
  The fractional concentration of exhaled nitric oxide (FeNO) is a surrogate biomarker for Th2-dependent bronchial inflammation. The present study investigated whether FeNO may characterize allergic rhinitis (AR) patients.
  
  
  METHODS
  A total of 553 AR patients (497 males, mean age 28.8 years) were evaluated. Those patients with a high FeNO underwent a 2-year follow-up.
  
  
  RESULTS
  Increased FeNO was associated with a significantly longer AR duration, impaired lung function, more severe symptoms, and more frequent bronchial hyperresponsiveness (BHR). At follow-up, 22 out of 82 patients (26.8%) with high FeNO levels (>50 ppb) developed asthma.
  
  
  CONCLUSIONS
  AR patients may frequently have high FeNO values, exceeding 50 ppb. This might be associated with an initial impaired lung function, BHR, a perceived worsening of respiratory symptoms, and potential progression to asthma.
authors.affiliation: Department of Medicine, IRCCS-Azienda Ospedaliera Universitaria San Martino-IST, Genoa, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Ciprandi
authors.forename: Fabio
authors.initials: F
authors.lastname: Gallo
authors.forename: Fabio Luigi Massimo
authors.initials: FL
authors.lastname: Ricciardolo
authors.forename: Ignazio
authors.initials: I
authors.lastname: Cirillo
mesh_terms: D000328:Adult; D001249:Asthma / Q000175:diagnosis* / Q000209:etiology; D015415:Biomarkers / Q000378:metabolism*; D001944:Breath Tests; D016535:Bronchial Hyperreactivity / Q000175:diagnosis*; D018450:Disease Progression; D045853:Exhalation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D012129:Respiratory Function Tests; D065631:Rhinitis, Allergic / Q000150:complications / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide