Effect of a prolonged topical glucocorticosteroid on interleukin-5 production and eosinophilic recruitment in the nasal submucosal compartment

Abstract

EnAbstract Aim Intranasal corticosteroids offer effective treatment for allergic rhinitis. The action of interleukin 5 (IL-5) (Th2-type cytokine) and its response to intranasal steroids has not been thoroughly studied in the deep compartment of the nasal mucosa. The aim of this study was to determine the influence of prolonged topical glucocorticosteroid on the allergic inflammatory responses in the deep compartment of the nasal mucosa in patients with allergic rhinitis. Materials and methods Fluticasone furoate spray was used once daily. Biopsies were obtained from 22 patients with perennial allergic rhinitis at different intervals: before treatment with nasal corticosteroids, and after 1, 6, and 12 months. Biopsies were taken from 18 individuals serving as a control group. All biopsies were examined by light microscopy and immunohistochemisty. Results The results showed the efficacy of fluticasone in reducing the number of eosinophils in both epithelial and subepithelial layers, which suppresses the allergic manifestations. The maximum reduction occurred after 12 months. This is achieved by reducing the number of eosinophils and IL-5 in both epithelial and subepithelial compartments. Conclusion Intranasal corticosteroids effectively reduce both the number of eosinophils and IL-5 expression inside activated eosinophils. They influence both the epithelium and the deep compartment of the nasal mucosa.