Bronchial Hyperresponsiveness in Pediatric Non-Cystic Fibrosis Bronchiectasis.

OBJECTIVE: The prevalence and significance of bronchial hyperresponsiveness (BHR) in patients with non-cystic fibrosis (CF) bronchiectasis remain unclear. The objective is to determine the prevalence of BHR, defined as a post-bronchodilator forced expiratory volume in 1 s (FEV1) improvement > 10%, in children with non-CF bronchiectasis and to assess its association with clinical, functional, and radiological characteristics. DESIGN: This retrospective, observational monocentric study included children with non-CF bronchiectasis followed-up at an university center for rare pediatric respiratory diseases. PATIENTS: Patients were eligible if they had performed spirometry with bronchodilator reversibility testing within 3 years of a diagnostic chest computed tomography (CT). MAIN OUTCOMES MEASURES: Asthma symptoms, asthma exacerbations, asthma treatments, allergic markers, infectious exacerbations, causes of bronchiectasis, FEV1, FEV1/forced vital capacity (FVC) ratio, reversibility, and mosaic attenuation on CT were compared between patients with and without BHR. RESULTS: Among 157 patients, 65 (male/female sex ratio 0.71, mean age 10 years old, asthma symptoms in over 56% of patients, 67% treated with inhaled corticosteroids) met the inclusion criteria. BHR was present in 32.3% of cases. Patients with BHR had a significantly altered lung function (baseline Z-score FEV1 -2.12 vs -0.87; FEV1/FVC -2.28 vs -0.85). No significant association was found between BHR and clinical and radiological characteristics. CONCLUSION: BHR is not associated with clinical, radiological or therapeutic characteristics in pediatric non-CF bronchiectasis, except a more severe airflow limitation. These findings highlight the importance of lung function assessment for non-CF bronchiectasis patients.