TOPLINE:
Sputum specialized proresolving mediators (SPMs), particularly resolvin D1 (RvD1), showed dynamic temporal changes and aided recovery during bacterial acute exacerbations of chronic obstructive pulmonary disease (AECOPD), unlike during viral exacerbations.
METHODOLOGY:
- SPMs are lipid mediators that may drive the resolution of airway inflammation by reducing proinflammatory signals and enhancing immune defense.
- Researchers recruited patients from the London COPD Exacerbation Cohort to examine how levels of SPMs, particularly RvD1, in the sputum of patients with COPD change over time during exacerbations and assess their association with the type of infection and recovery.
- Between November 2016 and April 2018, 65 patients (median age, 69 years; 65% men) were included and clinically assessed at baseline, at exacerbation onset, and during recovery at 1, 2, and 6 weeks following exacerbation onset.
- Patients documented daily symptoms of exacerbation in their diary cards and were trained to report those symptoms.
- Clinical assessments included spirometry, COPD tests, sputum and swab analyses, and cell experiments evaluated RvD1’s effect on viral and bacterial exacerbations.
TAKEAWAY:
- Overall, there were 68 exacerbations, 45.5% of AECOPD were caused by rhinoviruses, while 29.4% were caused by bacteria.
- Patients with viral exacerbations took significantly longer to recover than those with bacterial exacerbations (median recovery days, 21 vs 13; P < .001).
- They also showed a greater decrease in the change in the forced expiratory volume from baseline at 2 weeks following exacerbations than those with bacterial exacerbations (P = .019).
- At exacerbation onset, levels of sputum RvD1 were significantly higher in patients with bacterial exacerbations than in those with viral exacerbations (P = .015). RvD1 levels were strongly associated with different sputum inflammatory markers at different weeks following exacerbations (all P < .05).
IN PRACTICE:
“The increased sputum RvD1 response with bacteria induced AECOPD was distinguished from viral exacerbations and associated with a more rapid clinical recovery,” the authors wrote.
SOURCE:
This study was led by Lydia J. Finney, National Heart and Lung Institute, Imperial College London in London, England. It was published online on March 5, 2025, in the American Journal of Respiratory and Critical Care Medicine.
LIMITATIONS:
The study had a relatively small sample size. Moreover, data on sputum cell counts during exacerbations were missing, and bacterial culture methods were used instead of microbiome analysis.
DISCLOSURES:
This study was supported by grants from the Academy of Medical Sciences; National Heart and Lung Institute; and National Heart, Lung, and Blood Institute. Few authors reported receiving grants, consulting or personal fees, and honoraria; being on the advisory and other boards; holding patents, stock, and stock options; and being employees of various healthcare, research, and pharmaceutical organizations.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.
