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Difference in Airway Reactivity in Children With Atopic vs Nonatopic Asthma

1999; Elsevier BV; Volume: 116; Issue: 3 Linguagem: Inglês

10.1378/chest.116.3.619

1931-3543

Hiroyuki Mochizuki, Makoto Shigeta, Kenichi Tokuyama, Akihiro Morikawa,

Circadian rhythm and melatonin

Study objective To examine the difference in the mechanisms of bronchial hyperresponsiveness (BHR) in nonatopic asthma and in atopic asthma, we studied bronchial reactivity against nonspecific stimuli in children with atopic asthma and nonatopic asthma. Design and participants Fourteen children with nonatopic asthma, 24 children with atopic asthma, and 20 age-matched controls participated in this study. Measurements Inhalation challenge was performed by administering progressively doubling doses of methacholine with a continuous inhalation provocation method. The speed of bronchoconstriction to methacholine (Sm) and the speed of reversal of bronchoconstriction to methacholine after inhalation of aβ 2-agonist (r-Sm), which was considered to represent the effect of the β2-agonist, were calculated from the dose-response curve. Results The value of Sm was higher in the nonatopic asthma group than in the atopic asthma group and the control group. The value of r-Sm was also higher in the nonatopic asthma group than in the atopic asthma group, but did not differ from that in the control group. Conclusion These results indicate that bronchial reactivity against methacholine and the β2-agonist was greater in nonatopic asthma than in atopic asthma, and that the mechanism of BHR in children with nonatopic asthma may differ from that in children with atopic asthma. To examine the difference in the mechanisms of bronchial hyperresponsiveness (BHR) in nonatopic asthma and in atopic asthma, we studied bronchial reactivity against nonspecific stimuli in children with atopic asthma and nonatopic asthma. Fourteen children with nonatopic asthma, 24 children with atopic asthma, and 20 age-matched controls participated in this study. Inhalation challenge was performed by administering progressively doubling doses of methacholine with a continuous inhalation provocation method. The speed of bronchoconstriction to methacholine (Sm) and the speed of reversal of bronchoconstriction to methacholine after inhalation of aβ 2-agonist (r-Sm), which was considered to represent the effect of the β2-agonist, were calculated from the dose-response curve. The value of Sm was higher in the nonatopic asthma group than in the atopic asthma group and the control group. The value of r-Sm was also higher in the nonatopic asthma group than in the atopic asthma group, but did not differ from that in the control group. These results indicate that bronchial reactivity against methacholine and the β2-agonist was greater in nonatopic asthma than in atopic asthma, and that the mechanism of BHR in children with nonatopic asthma may differ from that in children with atopic asthma.