Significance of the IL-6 pathway in nasal polyposis in Chinese patients

Background: The interleukin-6 (IL-6) pathway is known to be important in Th17 cell differentiation and in the pathology of many inflammatory disorders. However, the significance of the IL-6 pathway in nasal polyposis (NP) in Chinese patients remains unclear. Objective: The aim of this study was to evaluate the functions of the IL-6 pathway in NP in Chinese patients. Methods: The levels of IL-6 pathway components, including IL-6, soluble IL-6 receptor (sIL-6R), phosphoSTAT3 (pSTAT3), and suppressor of cytokine signalling 3 (SOCS3), were assessed. The Th17 milieu was examined by measuring the levels of retinoid acid-related orphan receptor C (RORc) and IL-17A. Results: Levels of IL-6 pathway components, RORc, and IL-17A were significantly higher in both NP groups than in the control (P <0.05). Furthermore, significantly higher levels of pSTAT3, RORc, and IL-17A, and significantly lower levels of SOCS3 were found in the atopic group than in the non-atopic group (P <0.05). IL-6 and sIL-6R levels were not significantly different between the 2 NP groups (P >0.05). pSTAT3 exhibited significantly positive correlations with RORc and IL-17A (P <0.01). Conclusions: The expression levels of the IL-6 pathway components were significantly higher in NP patients. Moreover, p-STAT3 levels were much higher in the atopic group, and were associated with a more severe Th17 response. These results suggest that the IL-6 pathway may play a crucial role in the pathology of NP in Chinese patients, and atopy may contribute to NP by affecting the IL-6 pathway.