Intranasal steroids decrease eosinophils but not mucin expression in nasal polyps

• Published in: The European respiratory journal Vol. 24; no. 4; pp. 594 - 600
• Main Authors: Burgel, P-R, Cardell, L.O, Ueki, I.F, Nadel, J.A
• Format: Journal Article
• Language: English
• Published: Leeds Eur Respiratory Soc 01.10.2004; Maney
• Subjects: Administration, Intranasal; Adrenal Cortex Hormones - administration & dosage; Androstadienes - administration & dosage; Biological and medical sciences; Clinical Medicine; Eosinophils - drug effects; Fluticasone; Humans; Interleukin-8 - biosynthesis; Klinisk medicin; Lungmedicin och allergi; Medical and Health Sciences; Medical sciences; Medicin och hälsovetenskap; Mucin 5AC; Mucins - biosynthesis; Mucins - drug effects; Nasal Polyps - drug therapy; Neutrophil Infiltration - drug effects; Pneumology; Receptor, Epidermal Growth Factor - biosynthesis; Receptor, Epidermal Growth Factor - drug effects; Respiratory Medicine and Allergy; Tumor Necrosis Factor-alpha - biosynthesis; Tumor Necrosis Factor-alpha - drug effects; Steroid; Airway epithelium epidermal growth factor receptor interleukin-8 leukocyte recruitment mucous hypersecretion steroid treatment; Corticosteroid; Mucin; Nasal polyp; Decrease; Granulocyte; Immunosuppressive agent; Gene expression; Eosinophil
• ISSN: 0903-1936; 1399-3003; 1399-3003
• DOI: 10.1183/09031936.04.00014404

Increased mucin expression is a feature of nasal polyposis. Corticosteroids reduce polyp size and symptoms, but their effect on mucin production remains unknown. In this study, the effects of intranasal corticosteroids on MUC5AC mucin expression, nasal resistance, eosinophil and neutrophil infiltration, epidermal growth factor receptor (EGFR), interleukin (IL)-8, and tumour necrosis factor (TNF)-α expression was assessed in nasal polyps. In nine subjects, one nasal polyp was removed surgically before treatment and another was removed after 8 weeks of intranasal fluticasone (400 µg·day −1 ). Tissues were processed for in situ hybridisation and immunohistochemical staining. Described effects of fluticasone on nasal polyps (reduction in nasal resistance and in eosinophil infiltration) were evaluated. Morphometric analysis was performed to assess the effect of fluticasone on epithelial-, MUC5AC-, EGFR- and IL-8-stained areas, TNF-α-stained cells, and neutrophil numbers. Treatment with fluticasone decreased nasal resistance and intra-epithelial eosinophils. The MUC5AC-stained area in the epithelium was unchanged by treatment; MUC5AC mRNA expression was unaffected by treatment. EGFR-stained area, intra-epithelial neutrophil numbers, IL-8 and TNF-α expression were also unchanged by therapy. Intranasal fluticasone was effective in decreasing nasal airflow resistance and intra-epithelial eosinophils but had no effect on mucin or epidermal growth factor receptor expression or on neutrophil recruitment.