Fluticasone inhibits the progression of allergen-induced structural airway changes

Summary Background Inhaled corticosteroids are widely used as first‐line therapy in patients with asthma. The concept of early introduction is more and more accepted. Objective In our rat model of airway remodelling, we investigated whether treatment with inhaled fluticasone propionate can inhibit further progression of established structural airway changes. Methods Sensitized Brown Norway rats were exposed to aerosolized ovalbumin (1%) from day 14 to 42. From day 28 to 42, animals were treated with inhaled fluticasone or placebo 30 min before each allergen challenge. One control group was exposed to PBS from day 28 to 42, a second control group throughout the whole experiment. Results Exposure to ovalbumin during 2 weeks induced structural airway changes, including epithelial cell proliferation, increase in airway wall area and fibronectin deposition. Goblet cell number was increased, although not significantly compared with PBS. Continuing allergen exposure for 2 weeks further enhanced each of these features. In addition, the amount of collagen in the airway wall was enhanced by 4 weeks allergen exposure compared with PBS‐exposed animals. These additional increases were inhibited by treatment with fluticasone during the last 2 weeks. Conclusion The progression of established allergen‐induced structural airway changes in sensitized rats can be inhibited by treatment with fluticasone.