ABSTRACT
Asthma is a clinical syndrome characterized by its reversibility of airway ob struction, but several studies suggest that chronic asthma may be associated with the development of irreversible airway obstruction (1,2). In 1962, the American Thoracic Society noted that some asthmatics, particularly those who have had asthma for many years and/or present a severe form of the disease, may have persistent airflow obstruction (3). The pathophysiological mecha nism of asthma classically includes bronchospasm, hypersecretion, and chronic inflammation. More recently, attention has been focused on “ airway remodeling.’’ Healing begins in the early stage in any inflammatory process and results in repair, inducing a regeneration that leaves no residual trace of the previous injury and/or the replacement of injured tissue by connective tissue. In asthma, the most common changes accounting for a remodeling of the airways (2) include subepithelial fibrosis (4), activation of myofibroblasts
(5), hypertrophy or hyperplasia of smooth muscle and mucous glands (6-8), and elastic fiber disruption (9).
