Mucosal Inflammation and Asthma

Although postmortem studies in fatal asthma described abnormalities within the airways involving eosinophils, mast cells, and T-Iymphocytes, the full relevance of this mucosal inflammation to clinical disease was not appreciated until the advent of more recent extensive studies in vivo with direct airway sampling by fiberoptic bronchoscopy. Studies in asthma involving both endobronchiallavage, which samples cells either free within the airway lumen or not firmly adhered to the epithelium, and endobronchial biopsy, which allows assessment of tissue structure and cell populations, have identified abnormalities of airway cell infiltration and cell activation in asthma patients compared with nonasthmatic subjects. These abnormalities involve mast cells, eosinophils, T-Iymphocytes, macrophages, and epithelial cells.