MUC2 expression in human middle ear epithelium of patients with otitis media

Objective: To compare levels of expression of mucin gene 2 (MUC2), a major secretory mucin, in the middle ear of patients with otitis media (OM) and control patients. Design: Case-control study. Setting: Children's Hospital of Wisconsin, Milwaukee. Patients: Nineteen patients aged 6 months to 15 years undergoing routine ventilation tube insertion for recurrent OM or chronic OM with effusion and 8 controls with no history of OM undergoing cochlear implantation. Interventions: Biopsy of middle ear epithelium for RNA extraction. Main Outcome Measure: Expression of MUC2 by real-time reverse transcription-polymerase chain reaction. Results: Twenty-seven OM samples (17 recurrent and 10 with effusion) from 19 patients were analyzed and compared with 9 control samples from 8 patients. The mean MUC2 expression was 6.12 (95% confidence interval, 3.32-8.89) times that of the controls in the OM samples overall, 5.00 (95% confidence interval, 2.79-7.21) times that of controls in the recurrent OM samples, and 7.98 (95% confidence interval, 1.58-14.38) times that of controls in the OM with effusion samples. Conclusions: Levels of MUC2 expression in human middle ear epithelium are significantly increased in patients with OM overall, patients with recurrent OM, and patients with OM with effusion compared with controls. Mucins are fundamentally important in the middle ear, controlling viscoelastic properties of secretions and providing mucosal protection and bacterial clearance. Demonstration of these differences between patient groups highlights the need for greater understanding of molecular responses in OM, which may provide novel interventions for this common problem.