[Exhaled nitric oxide in children under 4 years of age with recurrent bronchitis].
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.
de Mir Messa
Inés
I
Unidad de Neumología Pediátrica y Fibrosis Quística, Hospital Universitari Vall d'Hebron, Barcelona, España. fernandezdemir@gmail.com
Moreno Galdó
Antonio
A
Cobos Barroso
Nicolás
N
Gartner
Silvia
S
Martín De Vicente
Carlos
C
Liñán Cortés
Santos
S
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
D000305:Adrenal Cortex Hormones; D000893:Anti-Inflammatory Agents; D009569:Nitric Oxide