# Progression of Structural Lung Disease in Different Aspergillus fumigatus Disease Phenotypes in Children with CF

## TL;DR

This study examines how different types of Aspergillus fumigatus infection in children with cystic fibrosis affect lung disease progression.

## Contribution

The study identifies four distinct Aspergillus disease phenotypes and their differing impacts on lung disease progression and ABPA risk in children with cystic fibrosis.

## Key findings

- Annual structural lung disease progression was higher in sensitisation and bronchitis phenotypes compared to colonisation.
- Children with allergic bronchitis had a 10-fold higher risk of developing ABPA compared to those with colonisation.
- Air trapping was common across all phenotypes but showed no differences in progression rates.

## Abstract

Aspergillus fumigatus (Asp) is frequently cultured from airways of children with Cystic Fibrosis (CwCF), but the impact on structural lung disease (SLD) remains unknown. In this retrospective study of 125 CwCF with a positive Asp airway culture (Asp+) at Sophia Children’s Hospital between 1988 and 2021, four Asp disease phenotypes were defined based on serum Asp-specific IgE (IgEAsp) and IgG (IgGAsp): colonisation, sensitisation, bronchitis, and allergic bronchitis. SLD was assessed on biennial chest CTs (n = 382) using the PRAGMA-CF score. Annual progression of SLD was modelled for the Asp disease phenotypes, adjusting for Pseudomonas aeruginosa and Allergic Bronchopulmonary Aspergillosis (ABPA). Annual SLD progression was high in all phenotypes but was higher in Asp sensitisation and bronchitis compared to colonisation. The proportion of air trapping was high in the full study population (mean 57%), but no differences were found in annual progression between the different Asp disease phenotypes. CwCF with Asp allergic bronchitis had a 10-fold higher risk to develop ABPA during the study follow-up than those with Asp colonisation. The four Asp disease phenotypes, colonisation, sensitisation, bronchitis, and allergic bronchitis, that were defined based on IgEAsp and IgGAsp show different rates of progression of SLD and different risks of ABPA development.