Anti-microbial immunity is impaired in COPD patients with frequent exacerbations

Aran Singanayagam; Su-Ling Loo; Maria Calderazzo; Lydia J Finney; Maria-Belen Trujillo Torralbo; Eteri Bakhsoliani; Jason Girkin; Punnam Veerati; Prabuddha S Pathinayake; Kristy S Nichol; Andrew Reid; Joseph Foottit; Sebastian L Johnston; Nathan W Bartlett; Patrick Mallia

It is important to note that causation cannot be inferred from the results of our study. Although we found reduced anti-microbial responses in patients with a history of frequent exacerbations, we cannot reliable conclude that these abnormalities directly lead to inherent increased exacerbation risk per se. There are likely to be a number of additional factors that may be contributing to the observed differences and, notably, in stable state analyses, frequent exacerbators showed trends towards greater ICS use and less current smoking. These confounders could contribute directly or indirectly to the differences observed, as previously reported 21, 41, 42 . We therefore consider our study to be hypothesis generating and emphasise the importance of future larger in vivo studies to more carefully dissect the influence of various factors and definitely answer the question of whether deficient antimicrobial immunity underlies propensity to exacerbation frequency in COPD. Previous studies have also indicated that exacerbation risk in COPD is dynamic and may change from year to year 4, 43 . A longer-term study with repeated airway sampling would be need to determine whether baseline antimicrobial responses are similarly dynamic in nature. author/funder. All rights reserved. No reuse allowed without permission.