Airway glucose in COPD exacerbations

Background Airway glucose (AG) is elevated in cystic fibrosis and is associated with increased susceptibility to bacterial infection. High levels of AG may contribute to bacterial infection in COPD but has not been investigated. We examined the relationships between AG, inflammation and infection in COPD. Methods AG was measured using the Amplex® Red assay in induced sputum (IS) and nasal lavage (NL) from COPD subjects, healthy smokers (SMK) and non-smokers (NS) undergoing experimental rhinovirus (RV) infection and in a cohort of COPD patients with naturally-acquired infections. Results Prior to infection AG was significantly higher in IS in COPD subjects compared with SMK and NS. In both experimental ( , Panels 1A and 1B) and natural (Panels 1C and 1D) exacerbations AG increased significantly in NL and IS. Peak AG in IS in the experimental infection COPD subjects correlated with inflammatory mediators (neutrophils r=0.69, P=0.002; NE r=0.74, P Conclusions AG levels are increased in IS in stable COPD and in both IS and NL in COPD exacerbations. AG correlates with inflammatory mediators and bacterial load in IS. This is the first in vivo evidence linking AG with airway inflammation and bacterial infections in COPD. Therapies that reduce levels of AG have potential as non-antibiotic treatments to prevent bacterial infections.