Bronchodilator responsiveness in children with cystic fibrosis and allergic bronchopulmonary aspergillosis

Extract

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity lung disease that occurs in approximately 9% of children with cystic fibrosis (CF) [1]. While ABPA is commonly associated with worsening lung function, differentiating ABPA from other causes of pulmonary function decline often poses a clinical challenge. This is reflected by major differences among the various diagnostic criteria for ABPA that have been suggested to date [2–5]. A positive bronchodilator response (BDR) is characteristic for asthma which is a common co-morbidity in CF patients, but whether this is helpful in differentiating ABPA from other causes of deterioration in lung function is currently unclear. A recent observational study of paediatric CF patients found a significant higher BDR in ABPA compared to patients not sensitised to Aspergillus fumigatus [6]; this stands in contrast to the CF Foundation consensus that did not identify airway obstruction reversibility as a characteristic of CF-related ABPA [5]. We therefore aimed to evaluate the clinical utility of BDR for diagnosis of ABPA in CF by comparing rates of positive BDR prior to a diagnosis of ABPA to CF patients experiencing acute lung function deteriorations for other causes.