Background: The factors responsible for inducing or maintaining airway inflammation are
poorly understood. Various studies have focussed on the mechanisms leading to allergic
airway inflammation in patients with asthma and rhinitis. The observation of local airway
inflammation in nonallergic patients with asthma or rhinitis, including those with nasal
polyposis, suggest that non-IgE–related mechanisms exist that may lead to airway
inflammation. Various lines of evidence suggest that epithelial cells may participate in local …