Transbronchial biopsy as a tool to evaluate small-airways disease in asthma. Pros

Asthma is an inflammatory disease and although the existence of small airways disease has been described, a few decades ago, in asthma and chronic obstructive pulmonary disease (COPD), the possibility that small airway inflammation/remodelling is involved in the pathophysiology and clinical manifestations of these conditions has recently been re-emphasised 1–3. Previous observations had shown small airways changes in asthma. Using surgically resected lung specimen of patients with asthma, Hamid et al. 1 observed an airway inflammatory process not only in large but also small airways, activated eosinophils being more numerous in peripheral airways. Small-airways disease has also been found in fatal asthma 4. The inner-wall area of distal airways was found to be increased in patients who died of asthma or other causes; structural changes such as smooth-muscle thickening were observed in peripheral airways. There was an increased interest in exploring small-airways inflammation, with the development of new medications such as hydrofluoroalkanes-propelled beclomethasone (QVARTM, 3M Pharmaceuticals, St-Paul, MN, USA). This …