LSC Abstract – Inflammation paradox – A detailed analysis of inflammatory profile in the airway wall of mild to moderate COPD

Aim: We recently reported hypocellularity of the lamina propria (LP) in large airway (LA) biopsies (Ebb) in COPD. We have now counted cell differentials in the LP of LA versus small airways (SA) from mild to moderate COPD current smokers (CS) and ex-smokers (ES), and compared them to tissues from normal lung function smokers (NLFS) and normal controls (NC). Methods: We obtained LA Ebb and SA resected lung tissues. Immuno-staining was done for CD68+ macrophages, neutrophil elastase, CD4 and CD8 for T cells. Cell counts were done in the LP up to 100-150 micron deep for the airways using image ProPlus 7.0 software and cells per square mm area were calculated. Results: Similar to our hypocellularity findings with LA we found decreased total cellularity in SA LP in NLFS, COPD-CS and ES subjects compared to NC (p Conclusion: We believe, the current dogma about airway wall inflammation in COPD is oversimplified and misleading in early stages of the disease. The majority of the cells in the LP did not stain with the antibodies used and are likely to be resident stromal cells.