Dissociation between airway inflammation and airway hyperresponsiveness in allergic asthma.
In asthma, the acute increment of airway responsiveness caused by exposure to allergen is associated with influx of eosinophils into the airways. The relationship between chronic airway hyperresponsiveness and airway inflammation is unclear, as they do not change consistently following long-term anti-inflammatory treatments. We studied 71 patients with chronic asthma and allergic sensitization to perennial allergens. Airway responsiveness was determined by inhalation of methacholine, and airway inflammation was quantified by induced sputum (n = 28) or bronchoalveolar lavage (n = 43) and bronchial biopsy (n = 20). The relationships between airway responsiveness and the numbers of different inflammatory cells were assessed by multiple regression analysis. No significant correlations were found between the degree of airway responsiveness and the numbers of inflammatory cells in sputum or bronchoalveolar lavage or bronchial biopsy. By contrast, baseline lung function was inversely related to the numbers of eosinophils and directly related to the numbers of macrophages. The eosinophil cationic protein contents of either sputum or bronchoalveolar lavage were significantly correlated with the percentages of eosinophils but not with airway responsiveness. We suggest that other factors (e.g., airway wall remodeling or autonomic dysfunction) may be responsible for most of the interindividual variability of airway responsiveness in asthma.
Crimi
E
E
Cattedra di Fisiopatologia Respiratoria, Dipartimento di Scienze Motorie e Riabilitative, Università di Genova, Italy.
Spanevello
A
A
Neri
M
M
Ind
P W
PW
Rossi
G A
GA
Brusasco
V
V
D000328:Adult; D000485:Allergens / Q000009:adverse effects*; D001249:Asthma / Q000276:immunology* / Q000503:physiopathology*; D001706:Biopsy; D001798:Blood Proteins / Q000032:analysis; D016535:Bronchial Hyperreactivity / Q000209:etiology*; D001985:Bronchial Provocation Tests; D001992:Bronchoalveolar Lavage Fluid; D047091:Eosinophil Granule Proteins; D004804:Eosinophils; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007249:Inflammation; D018836:Inflammation Mediators / Q000032:analysis; D007958:Leukocyte Count; D008297:Male; D012044:Regression Analysis; D012260:Ribonucleases; D012720:Severity of Illness Index; D013183:Sputum / Q000737:chemistry
D000485:Allergens; D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D018836:Inflammation Mediators; D012260:Ribonucleases