Effect of allergic bronchopulmonary aspergillosis on FEV1 in children and adolescents with cystic fibrosis : a European Cystic Fibrosis Society Patient Registry analysis

Objective To evaluate the effect of allergic bronchopulmonary aspergillosis (ABPA) on FEV1 percent predicted in children and adolescents with cystic fibrosis. Design Longitudinal data analysis (2008–2010). Setting Patients participating in the European Cystic Fibrosis Society Patient Registry. Participants 3350 patients aged 6–17 years. Main outcome measure FEV1percent predicted was the main outcome measure (one measurement per year per child). To describe the effect of ABPA (main explanatory variable) on FEV1 while controlling for other prognostic factors, a linear mixed effects regression model was applied. Results In 2008, the mean (±SD) FEV1 percent predicted was 78.6 (±20.6) in patients with ABPA (n=346) and 88 (±19.8) in those without ABPA (n=2806). After considering other variables, FEV1 in subjects with ABPA on entry to the study was 1.47 percentage points lower than FEV1 in patients of similar age without ABPA (p=0.003). There was no FEV1 decline associated with ABPA over the subsequent study years as the interaction of ABPA with age was not significant (p>0.05). For patients aged 11.82 years (population mean age), poor body mass index had the greatest impact on FEV1 in 2008, followed by high-risk genotype (two severe mutations), female gender, diabetes mellitus, chronic Pseudomonas aeruginosa infection and ABPA in descending order of effect size. Conclusions In contrast to the common clinical belief of ABPA having a serious impact on lung function, the difference in FEV1 between young patients with and without the complication was found to be modest when the effect of other prognostic factors was considered.