Localization of cystic fibrosis transmembrane conductance regulator in epithelial cells of nasal polyps and postoperative polypoid mucosae.
Cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride channel protein that plays an important role in electrolyte and water transport through the respiratory epithelial cells. In order to understand the possible role of CFTR in the pathogenesis of nasal polyps and postoperative polypoid mucosae, we aimed to characterize the localization of CFTR in the epithelia of nasal polyps and postoperative polypoid mucosae of subjects who did not manifest the phenotypic expression of cystic fibrosis. Immunohistochemical staining for CFTR, using monoclonal mouse anti-human CFTR, was performed on tissue sections of 4 normal turbinates and nasal polyps and postoperative polypoid mucosae from 10 patients who underwent endoscopic intranasal operations. CFTR showed a typical apical distribution in the normal turbinate mucosae whereas, in the nasal polyps, CFTR demonstrated a heterogenous pattern of localization comprising diffuse or scattered cytoplasmic labelling, very low to undetectable labelling, intense perinuclear staining and intermingled typical apical location. In postoperative polypoid mucosae, the pattern of CFTR localization was less heterogeneous than in the nasal polyp epithelial cells and showed a more prominent feature of diffuse cytoplasmic staining. These results suggest that an altered localization of the CFTR may have a role in the pathogenesis of nasal polyps and postoperative polypoid mucosa.