Reducing inflammation in COPD: the evidence builds

It has been accepted for more than 20 years that asthma is an inflammatory disease of the airways, but it is more recent that airways inflammation has been accepted to be important in chronic obstructive pulmonary disease (COPD).1

Airways inflammation is found in heavy smokers who have not developed airflow obstruction and is qualitatively similar to that seen in smoking-related COPD.2 3 Some, but not all, studies have shown a relationship between the severity of airflow obstruction and the degree of inflammation, lending support to the hypothesis that airway inflammation is important in COPD.4 5 The airway inflammation is characterised by an increase in CD8+ T cells and macrophages in the airway wall. Increased numbers of neutrophils are seen in the airway wall, particularly in more severe disease, but neutrophils are particularly prominent in sputum. 2 6 7 B cells are increased in more severe disease and there are increased numbers of mast cells.2 The main site of airflow obstruction in COPD is considered to be in the small airways which are inaccessible to normal bronchoscopic biopsy techniques; however, the pattern of airway inflammation seen in the large airways accessible to a bronchoscope and in the smaller airways …