Increased expression of angiogenin in nasal polyps

Background: The aim of this study was to determine the expression and distribution of angiogenin in nasal polyps and to evaluate the implication of such expression with respect to the development of nasal polyps. Methods: Normal inferior turbinate mucosa was obtained from 20 patients undergoing surgery for augmentation rhinoplasty. Nasal polyp samples were obtained from 20 patients undergoing endoscopic sinus surgery for chronic polypoid rhinosinusitis. A semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was performed for angiogenin mRNA. Sections of nasal polyps were immunostained for localization of angiogenin and quantitatively analyzed using computer-based image analysis. Western blot analysis was performed. Results: Semiquantitative RT-PCR and Western blot analysis showed that angiogenin expression in nasal polyps was increased compared with that in normal nasal mucosa. Using immunohistochemical staining, moderate-to-high levels of angiogenin were mainly localized in the infiltrating inflammatory cells of nasal polyps and faint staining was found in normal nasal mucosa. Conclusion: These results suggest that angiogenin may play a role in the pathophysiology of nasal polyps.