title: [Exhaled nitric oxide in children under 4 years of age with recurrent bronchitis].
abstract: BACKGROUND
  The objective of the study was to assess bronchial inflammation in preschool children with recurrent bronchitis by measuring exhaled nitric oxide.
  
  
  METHODS
  The study included patients under 4 years of age with at least 3 episodes of wheezing in the past year (n=63) and a control group (n=30). Exhaled nitric oxide was measured in samples collected offline during spontaneous tidal breathing with a face mask and stored in Mylar balloons.
  
  
  RESULTS
  The fractional exhaled nitric oxide concentration (FE(NO)) was higher in the group with bronchitis (mean [SD], 5.3 [1.3] parts per billion [ppb]) than in the control group (4.6 [1.1]ppb) (P=.02). There was a significant difference between the control group and children in the bronchitis group not treated with inhaled corticosteroids (P<.05), but not between controls and corticosteroid-treated patients. A relationship with eosinophil count was observed in that those with higher counts (>400 microL) had higher FE(NO) levels (P<.01). No relationship was observed between FE(NO) and a positive methacholine challenge test. Follow-up lasted at least 20 months. The initial FE(NO) level did not differ significantly according to whether patients were subsequently transient, infrequent, or frequent wheezers (5.2 [0.98]ppb, 5.6 [1.5]ppb, and 4.8 [1.34]ppb, respectively; P=.36).
  
  
  CONCLUSIONS
  In children under 4 years of age with recurrent wheezing bronchitis who were asymptomatic at study entry, a small increase in FE(NO) was observed although there was a good deal of overlap with the control group.
authors.affiliation: Unidad de Neumología Pediátrica y Fibrosis Quística, Hospital Universitari Vall d'Hebron, Barcelona, España. fernandezdemir@gmail.com
authors.forename: Inés
authors.initials: I
authors.lastname: de Mir Messa
authors.forename: Antonio
authors.initials: A
authors.lastname: Moreno Galdó
authors.forename: Nicolás
authors.initials: N
authors.lastname: Cobos Barroso
authors.forename: Silvia
authors.initials: S
authors.lastname: Gartner
authors.forename: Carlos
authors.initials: C
authors.lastname: Martín De Vicente
authors.forename: Santos
authors.initials: S
authors.lastname: Liñán Cortés
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D001944:Breath Tests; D001991:Bronchitis / Q000188:drug therapy / Q000378:metabolism*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009569:Nitric Oxide / Q000032:analysis*; D011657:Pulmonary Eosinophilia / Q000175:diagnosis* / Q000378:metabolism; D012008:Recurrence; D012135:Respiratory Sounds
chemical_list: D000305:Adrenal Cortex Hormones; D000893:Anti-Inflammatory Agents; D009569:Nitric Oxide