The role of NF-kB in chronic rhinosinusitis with nasal polyps

Abstract

Background: While the majority of nasal polyps seen in Western countries are eosinophilic, non-eosinophilic nasal polyps comprise a significant percentage in Asian countries. Given the importance of nuclear factor-kappaB (NF-κB) in the inflammatory processes and the poor description in Asian nasal polyps, the purpose of this study was to understand the role of NF-κB in the pathogenesis of chronic rhinosinusitis with nasal polyp (CRSwNPs) in Asian patients. Materials and methods: A total of 46 patients were enrolled in this study. 22 patients were diagnosed as CRSwNPs, 10 as chronic rhinosinusitis without nasal polyps (CRSsNP), and 14 as control subjects. Nasal polyps and uncinate tissues (UTs) were obtained. The tissues were prepared for hematoxylin-eosin staining and immunohistochemistry (IHC) study. And the total RNA was isolated for real time polymerase chain reaction for p65, IL-6, IL-8, ICAM-1, IL-1β, TNFα, and eotaxin. Results: When we analyzed histological type of nasal polyps in CRSwNPs group, eosinophilic type was 50% and non-eosinophilic type 50%. IHC revealed that the ratio of NF-κB p65-positive cells were significantly higher in the nasal polyps of the CRSwNPs group than in the UTs of the control, and CRSsNP groups. Between eosinophilic and non-eosinophilic nasal polyps, there was no difference. The mRNA expression of p65, IL-6, IL-8, and eotaxin were significantly higher in nasal polyps of the CRSwNPs than in the UTs of the control and the CRSsNP. But eosinophilic and non-eosinophilic nasal polyps showed no difference except IL-1β. Conclusions: Increased expression of NF-κB and NF-κB related inflammatory cytokine indicate that NF-κB has a pivotal role in the pathogenesis of CRSwNPs in both Caucasian and in Asian. An understanding of these mechanisms will provide a deeper insight into CRSwNPs pathogenesis and ultimately, improved therapeutic strategies. Further studies to evaluate the therapeutic possibility of NF-κB inhibition in CRSwNPs are needed.