Corticosteroid treatment selectively decreases mast cells in the smooth muscle and epithelium of asthmatic bronchi

• Published in: Allergy (Copenhagen) 2012-07, Vol.67 (7), p.958-961
• Main Authors: James, A., Gyllfors, P., Henriksson, E., Dahlén, S. E., Adner, M., Nilsson, G., Dahlén, B.
• Format: Article
• Language: English
• Subjects: Administration, Inhalation; Adrenal Cortex Hormones - administration & dosage; Adrenal Cortex Hormones - pharmacology; Anti-Asthmatic Agents - administration & dosage; Anti-Asthmatic Agents - pharmacology; Asthma; Asthma - immunology; Asthma - pathology; Biological and medical sciences; Bronchi - immunology; Case-Control Studies; Chronic obstructive pulmonary disease, asthma; corticosteroids; Dermatology; epithelium; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; mast cell; Mast Cells - drug effects; Medical sciences; Medicin och hälsovetenskap; Muscle, Smooth - immunology; Muscle, Smooth - pathology; Pathogenesis; Pneumology; Respiratory Mucosa - drug effects; Respiratory Mucosa - immunology; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; smooth muscle; Steroids
• ISSN: 0105-4538; 1398-9995; 1398-9995
• DOI: 10.1111/j.1398-9995.2012.02836.x

Background Mast cells are important in the pathophysiology of airway inflammation and evidence suggests their sub‐localisation within the airway is altered in asthma. Little is known about the effect of corticosteroids on mast cell localisation within the bronchi. Methods We therefore performed an immunohistochemical analysis of mast cell numbers within the smooth muscle, epithelium and submucosa of healthy subjects (n = 10) and well‐characterised asthmatic patients, using either β2‐agonists alone (n = 10) or β2‐agonists and inhaled corticosteroids (n = 10). Results Patients using inhaled corticosteroids displayed significantly lower numbers of mast cells within their epithelium and smooth muscle compared to those not treated with inhaled corticosteroids. Submucosal mast cells were not affected by corticosteroid treatment. Numbers of smooth muscle mast cells correlated with bronchial responsiveness and epithelial mast cells with exhaled NO. Conclusion We demonstrate that glucocorticosteroids differentially affect mast cell numbers within specific airway sub‐locations highlighting the importance of mast cell and smooth muscle/epithelial interactions in asthma pathogenesis.