Figure 1. Neutrophilic airway inflammation increases with disease severity.

(A) BALF neutrophils were higher in very severe COPD (GOLD IV) compared to participants with moderate COPD (GOLD II). (B) NE activity stratified across the GOLD stages demonstrates increased NE activity in GOLD IV. (C) Neutrophils were positively related to NE activity (Spearman r = 0.65, p<0.001) in BALF. Individual data points are shown with line representing mean values. # p<0.05 versus GOLD II.