Increased epithelial cell proliferation in nasal polyps.

BACKGROUND AND PURPOSE The mucociliary function of the sinonasal mucosa is an innate defense mechanism of the human nasal airway. Epithelial cell proliferation is required for cell renewal and repair of the sinonasal mucosa. In this study, the MIB-1 monoclonal antibody, which can detect the S-phase nuclear protein Ki-67, was used to evaluate the proliferation of the sinonasal mucosa in patients with various inflammatory conditions of the sinonasal mucosa. METHODS Specimens from the inferior turbinates of patients with nasal allergy (n = 12), vasomotor rhinitis (n = 20), nasal polyps (n = 22), and control subjects undergoing rhinoplasty (n = 5) and mucosa of chronic sinusitis patients [inferior turbinates (n = 10), middle turbinates (n = 10), and maxillary sinus (n = 9)] were fixed in neutral formalin and embedded in paraffin. MIB-1 monoclonal antibody was used to detect proliferation of epithelial cells. RESULTS Significantly increased epithelial cell proliferation was noted in nasal polyps compared to sinonasal mucosa. There was no difference among various sinonasal inflammatory conditions between patients and controls. CONCLUSIONS Increased epithelial cell proliferation in nasal polyps may play an important role in covering the epithelial defects caused by the rupture of the epithelium and prolapse of connective tissue in nasal polyps.