Abstract
Background: The severity of COPD is associated with proteobacteria phylum. However, the relationship between proteobacteria and computed tomography (CT) defined abnormalities in COPD is poorly understood.
Aim: We sought to compare the proteobacteria relative abundance in health versus COPD and to investigate the association of proteobacteria with COPD phenotypes.
Methods: Subjects with mild-to-moderate COPD or controls were recruited as part of the EvA consortium. Microbial profile was obtained through 16S rRNA gene sequencing of bronchoscopic bronchial brush sample. COPD subtypes were categorised into 4 groups assessed by CT: i) the airway dominated subtype, characterized by high percentage airway wall area (≥ 69.3% WA), ii) the emphysema dominated subtype, characterized by low lung density (≤ -925.6 Hounsfield units), iii) mixed subtype, characterized by both high percentage airway wall area and low lung density, iv) mild including cases without changes in density and percentage wall area in CT.
Results: The relative abundance of proteobacteria was significantly increased in the COPD groups i) 0.17 [n=49], ii) 0.19 [n=81], iii) 0.13 [n=134] and iv) 0.15 [n=15]) compared with healthy controls (0.11 [n=207]) (Kruskal-Wallis test; p=0.01). Additional Dunn's multiple comparisons test showed that the emphysema dominant subtype was the only group with significantly higher relative abundance of proteobacteria compared with controls (Adjusted p= 0.003).
Conclusion: The relative abundance of proteobacteria in bronchial brushes is higher in COPD versus healthy controls and is associated with emphysema dominated subtype.
Footnotes
Cite this article as: European Respiratory Journal 2021; 58: Suppl. 65, PA3421.
This abstract was presented at the 2021 ERS International Congress, in session “Prediction of exacerbations in patients with COPD”.
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).
- Copyright ©the authors 2021