TY - JOUR T1 - Clinical phenotypes of exacerbation are associated with differences in microbial composition and diversity in COPD JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2020.4931 VL - 56 IS - suppl 64 SP - 4931 AU - Holly Rachael Keir AU - Alison Dicker AU - Mike Lonergan AU - Megan Crichton AU - Bruce Miller AU - Ruth Tal Singer AU - James D Chalmers Y1 - 2020/09/07 UR - http://erj.ersjournals.com/content/56/suppl_64/4931.abstract N2 - Background: Exacerbation phenotyping is needed to improve personalised treatment. We tested the relationship of clinical exacerbation phenotypes to the sputum microbiome.Methods: Induced sputum was collected from COPD patients when stable and at exacerbation. Exacerbations were classified as bacterial, eosinophilic or viral/paucigranulocytic. Microbiome analysis was performed by 16s rRNA sequencing.Results: 46 patients were included. Mean age 70.8 years (SD±7.0), mean FEV1% predicted 63.3 (SD±22). Exacerbations were classified (bacterial=33, eosinophilic=19, viral=19). There was no obvious clustering of stable and exacerbation samples by PCoA (figure 1A, p=0.08, PERMANOVA). Differentially identified taxa by LEfSe are shown in figure 1B. Classifying exacerbations by phenotype resulted in significant differences by PERMANOVA, p=0.003 (figure 1C). Differences in alpha-diversity were observed across the 4 groups (ANOVA, p=0.0005), figure 1D. Higher CAT scores indicate more severe symptoms during exacerbations (p=0.0067).Conclusion: Exacerbations can be defined by clinical phenotypes which demonstrate differences in microbiome composition and diversity. Figure 1 A: PCoA clustering of stable and exacerbation samples. B: LEfSe Blue=more abundant in stable, Red=more abundant in exacerbation samples. C: PCoA 0=stable, 1=bacterial, 2=eosinophilic 3=viral. D: Shannon diversity between groups.FootnotesCite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 4931.This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only). ER -