The respiratory epithelium provides a physical, functional, and immunologic barrier to
protect the host from the potential harming effects of inhaled environmental particles and to
guarantee maintenance of a healthy state of the host. When compromised, activation of
immune/inflammatory responses against exogenous allergens, microbial substances, and
pollutants might occur, rendering individuals prone to develop chronic inflammation as seen
in allergic rhinitis, chronic rhinosinusitis, and asthma. The airway epithelium in asthma and …