Topical corticosteroid inhibits interleukin‐4, ‐5 and ‐13 in nasal secretions following allergen challenge

Summary Background Cytokines and chemokines produced by allergen‐reactive T‐helper type 2 (Th2) cells may be pivotal to the pathophysiology of allergic disorders. Objective This study was performed to assess the effect of 7 days of topical corticosteroid on nasal allergen challenge (NAC) in terms of eosinophils, cytokines and chemokines obtained by nasal lavage and filter paper methods. Methods Patients with grass pollen seasonal‐allergic rhinitis ( n =13) out of season received nasal challenge following matched placebo (twice daily into each nostril for 7 days) and fluticasone propionate (100 μg twice daily into each nostril for 7 days). Chemokine and cytokine levels were analysed using a sensitive automated bead immunoassay system at intervals up to 8 h after NAC. Results Levels of cytokines and chemokines from filter paper were generally higher than from nasal lavage. Fluticasone propionate caused a reduction in symptoms, total leukocyte counts and eosinophils, and abrogation of IL‐4, IL‐5, IL‐6 and IL‐13 responses in the filter paper taken in the late phase ( P <0.05 for IL‐4 and IL‐13, P <0.01 for IL‐5 and IL‐6). Levels of chemokines (eotaxin, RANTES, MCP‐1, MIP‐1α, IL‐8 and IP‐10) were also reduced in the late phase ( P <0.01 at 8 h). However, levels of IL‐2, IL‐3, IL‐7, IL‐12 (p40 and p70), ‐15, TNF‐α, IFN‐γ and GM‐CSF were not affected. Conclusion Fluticasone propionate has selective inhibitory effects on Th2 cytokine synthesis following nasal challenge, while also decreasing release of chemokines, but not affecting levels of Th1 cytokines.