Poor bronchodilator dose responsiveness predicts future asthma exacerbations in children
Published online: October 12, 2019
Airway lability, reflected by bronchodilator reversibility testing, is a characteristic feature of asthma. Although bronchodilator reversibility testing is routinely performed in the clinical setting to confirm the diagnosis of asthma and quantify asthma control, its utility in asthma phenotype determination and prediction of asthma outcomes is not clear.
In a research article recently published in The Journal of Allergy and Clinical Immunology: In Practice, Grunwell and colleagues questioned whether children and adolescents with poor bronchodilator dose responsiveness who require higher doses of bronchodilator to achieve bronchodilation would have unique phenotypic risk factors and increased risk of future exacerbation. They performed a test of maximal bronchodilation with escalating doses of up to 720 mcg albuterol sulfate in 630 patients, who were then followed for 12 months for the occurrence of asthma exacerbations.
In this study, 6.7% of children (N=20) and 9.3% of adolescents (N=31) had poor bronchodilator dose responsiveness, defined as attainment of maximal forced expiratory volume in one second (FEV1) with 720 mcg of albuterol. Risk factors for poor bronchodilator dose responsiveness included aeroallergen sensitization and markers of Type-2 inflammation, prior exacerbations, and greater asthma severity. Historical pneumonia and tobacco smoke exposure were also risk factors in children. Children and adolescents with poor bronchodilator dose responsiveness did not have greater asthma symptoms or more impaired quality of life but had ~2-fold increased odds of exacerbation and emergency department visits for asthma and ~3-fold increased odds of hospitalization by 12 months, independent of airflow obstruction. These results suggest that bronchodilator dose responsiveness may be useful for asthma phenotyping and prediction of asthma outcomes in children and adolescents.
The Journal of Allergy and Clinical Immunology: In Practice is an official scientific journal of the AAAAI, focusing on practical information for the practicing clinician.