Inhaled corticosteroid treatment and extracellular matrix in the airways in asthma.

Even mild asthmatics with a short duration of the disease show at the morphological level a picture of chronic inflammation with airway epithelial changes and influx of inflammatory cells into the airway mucosa. Several studies have shown that inhaled corticosteroid treatment can ameliorate this inflammation. In addition, even a morphologically normal epithelial structure may be restored. However, factors which may lead to more chronic disease have remained obscure. Recent studies are now focusing on the reversibility of collagen deposition in the airway epithelial basement membrane. Airway epithelial and stromal interactions may be important when a change at this level occurs.