Remodelling and Inflammation in Bronchial Asthma

Abstract

Chronic stable asthma is characterized by inflammation of the airway wall, with abnormal accumulation of basophils, eosinophils, lymphocytes, mast cells, macrophages, dendritic cells and myofibroblasts. The airway inflammation is not confined to severe asthma, but is also found in mild and moderate asthma. This inflammation results in a peculiar type of lymphocytic infiltration whereby Th2 lymphocytes secrete cytokines that orchestrate cellular inflammation and promote airway hyperresponsiveness. The term “airway remodelling” in bronchial asthma refers to structural changes that occurr in conjunction with, or because of, chronic airway inflammation. Airway remodelling results in alterations in the airway epithelium, lamina propria, and submucosa, leading to thickening of airway wall. The consequences of airway remodelling in asthma include incompletely reversible airway narrowing, bronchial hyperresponsiveness (BHR), smooth muscle contraction, airway edema, and mucus hypersecretion which may predispose persons with asthma to exacerbations and even death from airway obstruction.