HUMAN NASAL HOST DEFENSE AND SINUSITIS

Sinusitis is an exceptionally common disorder that affects an estimated 35 million Americans per year. The development of sinusitis requires both the presence of a virulent pathogen and the failure of the local immune system to prevent or effectively combat the infection. Identification of the components of the immune defense system of the upper respiratory tract and the possible areas of dysfunction that predispose to sinusitis may be important steps in the eventual prevention of this common disease. The nasal and sinus passages are lined by respiratory mucous membranes. Recent studies have identified some of the constituents found in mucus and their roles in human health and disease. However, the local immune system of the respiratory mucosa is largely unknown, and its role in sinusitis is conjectural. Nasal secretions include many proteins that serve important functions in local mucosal host defense. Most of these host-defense molecules are synthesized and secreted by serous cells in the submucous glands, and it appears that the serous cell is the resident antimicrobial cell in mucous membranes. Currently data suggest that serous cell secretion is abnormal in patients with recurrent sinusitis and that effective treatment leads to correction of the secretory abnormality along with improvement in sinusitis.