Geographic variation in environmental Aspergillus and clinical outcomes in COPD

<bold>Background:</bold> Aspergillus-associated disease is associated with adverse outcomes in COPD. Environmental variation and individual exposure to Aspergillus in COPD remains unclear. <bold>Methods:</bold> Patients with COPD were recruited in 2 geographic locations, variable in climate and seasonality: Singapore (Sg) (n=43) and Vancouver (Van), Canada (n=12). Outdoor/Indoor air and surface dust in each participant’s home was prospectively assessed by metagenomic sequencing. Clinical data and environmental parameters including indoor temperature and humidity were concurrently assessed. <bold>Results:</bold> Indoor temperature (median: 21.7°C: Van vs 29.4: Sg, p<0.001) and relative humidity (median: 41.7%: Van vs 73.8%: Sg, p<0.001) were significantly lower in Vancouver relative to Singapore. Indoor Aspergillus species in the homes of patients with COPD varied between countries. A. terreus, A. mulundensis and A. novofumigatus predominated in Vancouver, while A. nidulans, A. aculeatinus, A. welwitschiae, A. awamori and A. pseudoglaucus predominated in Singapore. A. fumigatus was detected in both locations, and relative abundance positively correlated with exacerbation frequency in COPD, independent of location (r=0.27; p=0.003 in Sg and r=0.49; p=0.019 in Van). <bold>Conclusion:</bold> While several Aspergillus species vary by geographic region, A. fumigatus in the air are associated with COPD exacerbations, independent of geography or patient origin. <bold>Funding:</bold> This work is supported by the Singapore Ministry of Health’s National Medical Research Council under the Clinician-Scientist Individual Research Grant MOH-001356 (S.H.C) and a Clinician-Scientist Award MOH-000710 (S.H.C) and Transition Award MOH- 001275-00 (P.Y.T) and the Singapore Ministry of Education under its AcRF Tier 1 Grant (RT1/22) (S.H.C)