Longitudinal Study on Clinical Predictors for Allergic Bronchopulmonary Aspergillosis in Children and Young People with Cystic Fibrosis Highlights the Impact of Infection with Aspergillus and Pseudomonas and Ivacaftor Treatment

Allergic bronchopulmonary aspergillosis (ABPA) is a well-known complication in children and young people with cystic fibrosis (CF) and without treatment causes structural lung damage. We performed a longitudinal observational study to identify clinical risk factors for ABPA in a cohort of children and young people with CF aged 8 to 17 years at baseline. Anonymised annual review UK CF Registry data from 2009 to 2019 for patients aged 8-17 years in 2009 were collected, with lung transplant recipients excluded. Baseline characteristics are presented for the whole group and cross-sectional comparisons made according to the presence of ABPA or not in 2009. Longitudinal analysis from 2009 to 2019 was completed on the group without ABPA in 2009 to identify predictors for the subsequent development of ABPA using a complementary log-log regression model. In 2009, there were 1612 patients, of which 1420 were ABPA-negative and 192 ABPA-positive. <i>Aspergillus</i> colonisation (<i>p</i> = 0.01) and IV antibiotic use (<i>p</i> < 0.0001) were associated with having ABPA in 2009. Longitudinal analysis of the group without ABPA in 2009 identified male gender, younger age, lower lung function, <i>Pseudomonas aeruginosa</i> infection, and <i>Aspergillus</i> colonisation to be significantly associated with the development of ABPA (<i>p</i> < 0.0001). Ivacaftor was significantly associated with reduced ABPA (OR 0.46, <i>p</i> = 0.01) but not lumacaftor/ivacaftor (OR 0.64, <i>p</i> = 0.28). Chronic oral macrolide use was significantly associated with increased risk of development of ABPA (OR 1.30, <i>p</i> < 0.0001). This study shows that lower lung function, <i>Aspergillus</i> colonisation, and <i>Pseudomonas aeruginosa</i> infection in children with CF were associated with the development of ABPA, highlighting the need for enhanced surveillance in these patients. This is the first study to show a protective association of ivacaftor and ABPA.