Objective: Neutrophil infiltration in patients with sinonasal inverted papilloma (SNIP) is significantly high. Whether IL-17, which is a potent factor mediating neutrophilic inflammation, is involved in the neutrophilic phenotype of SNIP is investigated in the current study.
Study design: Laboratorial study.
Participants: Nasal papilloma and inferior turbinate were collected from patients with SNIP (n = 50) and control subjects with septal deviation (n = 15).
Methods: IL-17 + cells were evaluated in tissues obtained from patients with SNIP and control subjects with septal deviation, by immunohistochemistry and flow cytometry.
Main outcome measures: The IL-17 + cells were mainly localised in mononuclear cells and neutrophils, and were up-regulated in the SNIP samples compared with those in the controls. The IL-17 + T-cell subsets mainly included CD4+ (Th17, 60.0%) and CD8+ (Tc17, 30.0%), and both subsets were enhanced in the SNIP samples than controls. The total level of IL-17 + cells was significantly correlated with neutrophil infiltration in the SNIP tissues. Furthermore, the SNIP homogenates could significantly promote IL-17 production in peripheral blood mononuclear cells.
Conclusions: An increase in IL-17 + cells is evident in SNIP and may be involved in neutrophil infiltration in local tissues. IL-17 could be a potential therapeutic target to relieve the neutrophilic pathological change in SNIP.
Keywords: IL-17; inflammation; neutrophils; sinonasal inverted papilloma.
© 2019 John Wiley & Sons Ltd.