Residential exposure to spp is associated with exacerbations in COPD.

Background: Sensitisation to 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 and the occurrence of (Asp f) allergens in the environment were determined and immunological responses to 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 spp were identified in Singapore and Vancouver, respectively. Despite climatic, temperature and humidity variation, was detectable in the environment from both locations. The relative abundance of environmental 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 exposure in the home environment including air and surfaces with resulting sensitisation carries pathogenic potential in individuals with COPD. Targeting domestic abundance may reduce COPD exacerbations.