Difficult asthma in children: an analysis of airway inflammation.
BACKGROUND
Difficult asthma in children displays distinct clinical patterns, and its physiopathology remains poorly understood.


OBJECTIVE
To determine the characteristics of the bronchial inflammatory profile in children with difficult asthma.


METHODS
We performed endobronchial biopsy and bronchoalveolar lavage in 28 children with persistent bronchial obstruction despite high doses of inhaled corticosteroids and regular treatment with long-acting beta(2)-agonists: 13 had persistent symptoms and 15 had few or no symptoms.


RESULTS
The number of eosinophils (P =.03) and neutrophils (P =.04) in the epithelium was significantly higher in symptomatic children than in children with few symptoms. Reticular basement membrane thicknening was similar in both groups. IFNgamma levels (P =.03) and IFNgamma/IL-4 ratio (P =.01) were significantly higher in children with few symptoms.


CONCLUSIONS
In symptomatic children, T(H)2-type inflammation was associated with the presence of activated eosinophils in the epithelium, whereas asthma in children with few symptoms was associated with an increase in T(H)1 cytokine levels. The high levels of IFNgamma suggest that this T(H)1 cytokine may modulate the local inflammatory response.
de Blic
Jacques
J
Service de Pneumologie et d'Allergologie Pédiatriques, Hôpital Necker-Enfants Malades, Paris, France.
Tillie-Leblond
Isabelle
I
Tonnel
André Bernard
AB
Jaubert
Francis
F
Scheinmann
Pierre
P
Gosset
Philippe
P
D001249:Asthma / Q000276:immunology / Q000503:physiopathology*; D001991:Bronchitis / Q000276:immunology / Q000503:physiopathology*; D018893:Bronchoalveolar Lavage; D001999:Bronchoscopy; D016022:Case-Control Studies; D002452:Cell Count; D002648:Child; D004804:Eosinophils / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D009504:Neutrophils / Q000276:immunology; D012129:Respiratory Function Tests; D020545:Respiratory Mucosa / Q000166:cytology / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology