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

Genetic MBL deficiency has been previously shown to be associated with both increased 25, 36 and reduced 37 exacerbation frequency in COPD. Although serum MBL concentrations have been shown to not differ between frequent and infrequent exacerbators 36 , a previous study reported reduced bronchoalveolar lavage MBL concentrations in COPD versus healthy subjects 38 . Our data extends these observations by demonstrating that deficient airway MBL-2 at baseline and during subsequent exacerbation might predispose frequent exacerbators to increased secondary bacterial infection. A previous study reported that the presence of rhinovirus is associated with increased S.pneumoniae colonization in children with MBL gene polymorphisms, further suggesting a role for MBL in virusinduced secondary bacterial infection 39 . Given that nebulised plasma-derived MBL has been shown to restore phagocytic function in smoke-exposed mice 40 , our data raise speculation that administration of MBL could additionally be considered as an effective preventative and/or therapeutic strategy for COPD exacerbations. Further studies are needed to evaluate this.