However, the relative contribution of each cell type is not well understood. Increased airway smooth muscle mass may be collectively due to airway infiltration of myofibroblasts, neighbouring airway smooth muscle cells in the bundle, or circulating hemopoietic progenitor cells. The precise source of these cells remains unknown. There is emerging evidence to suggest that the migration of airway smooth muscle cells may contribute to cellular hyperplasia, and thus increased airway smooth muscle mass. A key structural change inherent in airway remodelling is increased airway smooth muscle mass. Airway remodelling is an important feature of asthma pathogenesis.
