EFFECTS OF ICSs ON STRUCTURAL CHANGES
Epithelial Findings
In asthma, the bronchial epithelium is modified and appears
fragile and activated. Abnormalities include loss of the most
superficial layer of the epithelium, destruction of ciliated cells,
upregulation of growth factor release, and overexpression of
receptors such as epidermal growth factor receptors. The gross
morphology of the epithelium observed on endobronchial biopsies
has been controversial. The shedding of the epithelium reported
early by investigators looking at endobronchial biopsies
is now thought to be due at least in part to the sampling procedure
(30). Despite this potential confounding factor, the fragility
of the epithelium remains a reality.