Residential exposure to Aspergillus spp. is associated with exacerbations in COPD

• Main Authors: Tiew, Pei Yee, Leung, Janice M., Mac Aogáin, Micheál, Johal, Parteek, Jaggi, Tavleen Kaur, Yuen, Agnes Che Yan, Ivan, Fransiskus Xaverius, Yang, Julia, Afshar, Tina, Tee, Augustine, Koh, Mariko Siyue, Lim, Yee Hui, Wong, Anthony, Chandrasekaran, Lakshmi, Dacanay, Justine, Drautz-Moses, Daniela Isabel, Ong, Thun How, Abisheganaden, John Arputhan, Chew, Fook Tim, Schuster, Stephan Christoph, Carlsten, Christopher, Chotirmall, Sanjay Haresh
• Other Authors: Lee Kong Chian School of Medicine (LKCMedicine)
• Format: Article
• Language: English
• Published: 2025
• Subjects: Medicine, Health and Life Sciences; Aspergillus; Chronic obstructive lung disease
• Online Access: https://hdl.handle.net/10356/182585
• Institution: Nanyang Technological University

Background: Sensitisation to Aspergillus fumigatus is linked to worse outcomes in patients with COPD; however, its prevalence and clinical implications in domestic (residential) settings remains unknown. Methods: Individuals with COPD (n=43) recruited in Singapore had their residences prospectively sampled and assessed by shotgun metagenomic sequencing including indoor air, outdoor air and touch surfaces (a total of 126 specimens). The abundance of environmental A. fumigatus and the occurrence of A. fumigatus (Asp f) allergens in the environment were determined and immunological responses to A. fumigatus allergens determined in association with clinical outcomes including exacerbation frequency. Findings were validated in 12 individuals (31 specimens) with COPD in Vancouver, Canada, a climatically different region. Results: 157 metagenomes from 43 homes were assessed. 11 and nine separate Aspergillus spp. were identified in Singapore and Vancouver, respectively. Despite climatic, temperature and humidity variation, A. fumigatus was detectable in the environment from both locations. The relative abundance of environmental A. fumigatus was significantly associated with exacerbation frequency in both Singapore (r=0.27, p=0.003) and Vancouver (r=0.49, p=0.01) and individuals with higher Asp f 3 sensitisation responses lived in homes with a greater abundance of environmental Asp f 3 allergens (p=0.037). Patients exposed and sensitised to Asp f 3 allergens demonstrated a higher rate of COPD exacerbations at 1-year follow-up (p=0.021). Conclusion: Environmental A. fumigatus exposure in the home environment including air and surfaces with resulting sensitisation carries pathogenic potential in individuals with COPD. Targeting domestic A. fumigatus abundance may reduce COPD exacerbations.