Intranasal steroids decrease eosinophils but not mucin expression in nasal polyps.
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)-alpha 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 microg.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-alpha-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-alpha 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.
Cardiovascular Research Institute, Box 0130, University of California San Francisco, San Francisco, CA 94 143-0130, USA.
P-R
PR
Burgel
L O
LO
Cardell
I F
IF
Ueki
J A
JA
Nadel
D000281:Administration, Intranasal; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D000730:Androstadienes / Q000008:administration & dosage*; D004804:Eosinophils / Q000187:drug effects*; D066246:ErbB Receptors / Q000096:biosynthesis / Q000187:drug effects; D000068298:Fluticasone; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis; D055271:Mucin 5AC; D009077:Mucins / Q000096:biosynthesis / Q000187:drug effects*; D009298:Nasal Polyps / Q000188:drug therapy*; D020556:Neutrophil Infiltration / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000187:drug effects
D000305:Adrenal Cortex Hormones; D000730:Androstadienes; D016209:Interleukin-8; C524678:MUC5AC protein, human; D055271:Mucin 5AC; D009077:Mucins; D014409:Tumor Necrosis Factor-alpha; D000068298:Fluticasone; D066246:ErbB Receptors