• Pei Yee Tiew, Alison J Dicker, Holly R Keir, Mau Ern Poh, Sze Lei Pang, Micheál Mac Aogáin, Branden Qi Yu Chua, Jiunn Liang Tan, Huiying Xu, Mariko Siyue Koh, Augustine Tee, John Arputhan Abisheganaden, Fook Tim Chew, Bruce E Miller, Ruth Tal-Singer, James D Chalmers, and Sanjay H Chotirmall.
• Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Singapore.
• Eur. Respir. J. 2021 Mar 1; 57 (3).

IntroductionThe chronic obstructive pulmonary disease (COPD) bacteriome associates with disease severity, exacerbations and mortality. While COPD patients are susceptible to fungal sensitisation, the role of the fungal mycobiome remains uncertain.MethodsWe report the largest multicentre evaluation of the COPD airway mycobiome to date, including participants from Asia (Singapore and Malaysia) and the UK (Scotland) when stable (n=337) and during exacerbations (n=66) as well as nondiseased (healthy) controls (n=47). Longitudinal mycobiome analysis was performed during and following COPD exacerbations (n=34), and examined in terms of exacerbation frequency, 2-year mortality and occurrence of serum specific IgE (sIgE) against selected fungi.ResultsA distinct mycobiome profile is observed in COPD compared with controls as evidenced by increased α-diversity (Shannon index; p<0.001). Significant airway mycobiome differences, including greater interfungal interaction (by co-occurrence), characterise very frequent COPD exacerbators (three or more exacerbations per year) (permutational multivariate ANOVA; adjusted p<0.001). Longitudinal analyses during exacerbations and following treatment with antibiotics and corticosteroids did not reveal any significant change in airway mycobiome profile. Unsupervised clustering resulted in two clinically distinct COPD groups: one with increased symptoms (COPD Assessment Test score) and Saccharomyces dominance, and another with very frequent exacerbations and higher mortality characterised by Aspergillus, Curvularia and Penicillium with a concomitant increase in serum sIgE levels against the same fungi. During acute exacerbations of COPD, lower fungal diversity associates with higher 2-year mortality.ConclusionThe airway mycobiome in COPD is characterised by specific fungal genera associated with exacerbations and increased mortality.Copyright ©ERS 2021.

9 keywords...

hide…