Increase in IL-17-positive cells in sinonasal inverted papilloma.

Abstract

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. Laboratorial study. Nasal papilloma and inferior turbinate were collected from patients with SNIP (n=50) and control subjects with septal deviation (n=15). IL-17+cells were evaluated in tissues obtained from patients with SNIP and control subjects with septal deviation, by immunohistochemistry and flow cytometry. 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. 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.