Induced sputum eosinophils and neutrophils and bronchiectasis severity in allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity reaction to the fungus Aspergillus fumigatus that may progress to bronchiectasis. The aim of the present study was to characterize airway inflammation in patients with clinically stable ABPA and asthma, and to correlate this with bronchiectasis severity. Subjects with ABPA and central bronchiectasis (ABPA‐CB; n=16) and ABPA with serological evidence alone (ABPA‐S; n=10) were studied. Comparison groups were A. fumigatus‐sensitized asthma (n=19), non‐A. fumigatus‐sensitized asthma (n=15) and healthy controls (n=8). Hypertonic saline challenge, sputum induction and high‐resolution computed tomography (HRCT) of the chest were performed. Sputum eosinophil numbers were markedly elevated in ABPA‐CB (median 8.4%) compared to ABPA‐S (2.4%), A. fumigatus‐sensitized asthma (1.8%), asthma (1.8%) and controls (0.3%) (p