T(H)2 Cytokine Expression in Atopic Children with Otitis Media with Effusion

Background: Otitis media with effusion (OME) is more common in atopic children. Few studies have looked for the presence of inflammatory mediators in the middle-ear effusions of this population.

Objective: We hypothesize that atopic children with OME have a different inflammatory cell and cytokine profile than nonatopic patients with the disease.

Methods: Twenty-six patients with OME undergoing myringotomy and ventilation tube placement were recruited at the McGill University Hospital Center. The atopic status was determined for each patient by using standard skin testing. By means of immunocytochemistry, fluid specimens were assessed for T lymphocytes (CD3), eosinophils (major basic protein), neutrophils (elastase), mast cells (tryptase), and basophils (BB1). By using in situ hybridization, the expression of IL-4, IL-5, and IFN-gamma was assessed.

Results: There is a higher percentage of eosinophils and T lymphocytes in atopic patients with OME (n = 8) compared with that seen in nonatopic patients (n = 18, P <.01). There is a higher percentage of neutrophils in nonatopic patients with OME compared with that seen in atopic patients (P <.01). In examining cytokine profiles, there is a higher percentage of cells expressing IL-4 and IL-5 in atopic patients with OME compared with that seen in nonatopic patients (P <.01).

Conclusion: The predominance of eosinophils, T lymphocytes, and T(H)2 mediators in the middle-ear effusions of atopic children provides evidence that allergy might play a role in the pathogenesis of OME.