Profiling cellular and inflammatory changes in the airway wall of mild to moderate COPD

ABSTRACT Background and objective The objective of this study was to enumerate total cells and the number of inflammatory cell differentials in large airways (LAs) versus small airways (SAs) of mild‐moderate COPD, and against appropriate controls. Methods For LA, we used endobronchial biopsies and for SA resected lung tissues. Immunostaining was enumerated (cells per mm2) for macrophages, neutrophils, CD4 and CD8 T cells in the lamina propria (LP) up to 150 µM deep for LA and full wall thickness for SA. Results We confirmed hypocellularity in the LA and in the SA wall in smokers and COPD (P