Role of Thymic Stromal Lymphopoietin in the Pathogenesis of Nasal Polyposis

Introduction: Polyposis is an end form of chronic mucosal inflammation in a number of disorders and has an important impact on patient's life quality. Thymic stromal lymphopoietin (TSLP) is involved in many inflammatory processes such as asthma and allergic rhinitis (AR). The aim of this study is to elucidate the role of TSLP in the pathogenesis of polyposis. Methods: Ninety-four patients with nasal polyposis (NP) and/or allergic rhinitis (AR) were treated with inferior turbinectomy and polyp resection. Levels of TSLP in the nasal epithelial layer were measured; expression of TSLP receptor and OX40 ligand (OX40L) was assessed in isolated nasal mucosal dendritic cells (DC); tumor necrosis factor (TNF), interleukin (IL)-4 and interferon (IFN)-gamma expressions were determined in isolated nasal mucosal CD4(+) T cells. Results: The levels of TSLP in nasal epithelial layer were higher in the NP group than in the non-NP group. Higher expression of TSLP receptor and OX40L were detected in DCs of NP nasal mucosa. TNF-alpha(+) IL-4(+)CD4(+) T cells were detected in NP/AR nasal mucosa; TNF+ IFN-gamma(+) CD4(+) T cells were identified in NP/non-AR nasal mucosa. TSLP-primed DCs drove naive CD4(+) T cells to become TNF+ IL-4(+) CD4(+) T cells, whereas TSLP/lipopolysaccharide-primed DCs induced naive CD4(+) T cells to become TNF+ IFN-gamma(+) T cells. Conclusions: The data indicate that TSLP is involved in the pathogenesis of polyposis.