Department of Otolaryngology--Head and Neck Surgery, University of Newcastle, Freeman Hospital, UK.
OBJECTIVE: The aim of this study was to investigate mucin expression in chronic sinusitis compared to that in normal nasal mucus. STUDY DESIGN AND SETTING: Sinus mucus samples were collected during functional endoscopic sinus surgery (FESS). The expression of 3 airway mucins, MUC2, MUC5AC, and MUC5B, was determined by ELISA. RESULTS: The 3 mucins are expressed in chronic sinusitis and in normal nasal mucus. MUC5AC and MUC5B represent a major component in sinus mucins while MUC5B and MUC2 predominated in normal nasal mucin. In sinus mucins, upregulation of MUC5AC was associated with downregulation of MUC2 and vice versa. This inverse relationship was strengthened in the presence of nasal polyps. CONCLUSION: At least 3 mucins are expressed at various levels in chronic sinusitis. An inverse relationship was identified between expression of MUC5AC and MUC2. Large prospective studies are required to unravel the complexities of sinus mucus in chronic sinusitis. SIGNIFICANCE: Mucins may be used as markers for assessment of disease severity and may also help as prognostic indicators following medical or surgical treatment.