Group 2 Innate Lymphoid Cells Are Increased in Nasal Polyps in Patients with Eosinophilic Chronic Rhinosinusitis
Saturday, March 4, 2017: 3:00 PM
Thomas B. Murphy Ballroom 1 (Georgia World Congress Center, Building B)
Ichiro Tojima, , , , , ,
Rationale: Group 2 innate lymphoid cells (ILC2s) represent a critical innate cellular source of type 2 cytokines and may play important roles in various diseases. We examined the role of ILC2s in the pathogenesis of two subgroups of chronic rhinosinusitis with nasal polyps (CRSwNP); eosinophilic and nonn-eosinophilic CRS (ECRS and non-ECRS). 

Methods: We analyzed the prevalence of ILC2s in sinonasal mucosa and in peripheral blood from patients with ECRS and non-ECRS. Patients with CRS without nasal polyps (CRSsNP) and those without CRS were used as controls. ILC2s were analyzed by FACS and were identified as lineage- CD45+ CD127+ CRTH2+ cells. Isolated nasal epithelial cells were stimulated with Alternaria and the amounts of IL-33 in the supernatants were analyzed using ELISA.

Results: The prevalence of ILC2s in nasal tissues was significantly higher in patients with ECRS as compared to those with non-ECRS or CRSsNP. ILC2 prevalence correlated positively with the number of eosinophils in tissues. The prevalence of ILC2s in blood was not different between patients with ECRS and those with non-ECRS, while the percentage of blood eosinophils was significantly higher in patients with ECRS. The prevalence of blood ILC2s was higher in patients with allergic rhinitis (AR) and elevated serum IgE levels. Alternaria-induced IL-33 secretion was significantly increased in nasal epithelial cells derived from patients with ECRS as compared to those from patients with non-ECRS or CRSsNP.

Conclusions: ILC2s may be involved in the pathogenesis of CRSwNP, in particular in patients with tissue eosinophilia (i.e. ECRS).