Inflammation, lung function, symptoms and reliever use in chronic obstructive pulmonary disease

<bold>Background:</bold> Exacerbations of chronic obstructive pulmonary disease (COPD) may be linked to increased airway inflammation. We investigated the relationships between inflammation, lung function, symptoms, reliever use and their associations with COPD exacerbations. <bold>Methods:</bold> This 12-week observational study (<ext-link>NCT04168216</ext-link>) with a 4-week run-in included adults (≥40 years) with symptomatic COPD and blood eosinophil counts >0.1 x 10⁹ cells/L. Participants were switched to maintenance aclidinium bromide 340 μg/formoterol fumarate 12 μg (BID) and reliever salbutamol (100 μg/puff). Data were collected daily by participants at home using devices to measure fractional exhaled nitric oxide (FeNO), lung function, symptoms and salbutamol use. Exacerbation events, Exacerbations of COPD Tool (EXACT) events and composite endpoint for exacerbations in COPD (CompEx) events were captured prospectively. <bold>Results:</bold> Thirty-two participants were enrolled (<bold>Table</bold>); of 24 participants with ≥1 event, 41.7%/29.2%/95.8% had ≥1 exacerbation/EXACT event/CompEx event, respectively. Relative to baseline, greater FeNO levels, worsening respiratory symptoms and increased salbutamol use were associated with clinical events. <bold>Conclusions:</bold> Increased inflammation, worsening symptoms and increased reliever use were associated with exacerbation, EXACT and CompEx events. Findings suggest a potential role for anti-inflammatory treatment to prevent COPD exacerbations. <fig><object-id>erj;66/suppl_69/PA2452/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>