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

Abstract

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: FEV₁ percent 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.

Keywords: allergic bronchopulmonary aspergillosis; cystic fibrosis; lung function.