Pathology and Pharmacotherapeutics of Immune-mediated Sensorineural Hearing Loss

Abstract

The immune system of the inner ear has been highlighted as a novel candidate therapeutic target for sensorineural hearing loss. Macrophages are thought to play an important role in inner ear immunity, because the majority of leukocytes in the inner ear exhibit macrophage phenotypes and reside within the inner ear even under the steady state condition. Recent progress in the field of basic research has demonstrated that tissue macrophages have diverse functions, including pattern recognition with nonspecific receptors to be activated the initial process of innate immunity, antigen presentation, and cytokine secretion.

In this review, we discuss the distribution of immunocompetent cells in the inner ear and their currently known roles, as well as the clinical concepts and diagnostic criteria of autoimmune inner ear disease (AIED), and the newly developed therapeutic approaches for AIED, including utilization of biologicals. Given that macrophages are the major immunocompetent cells in the inner ear, clarification of their roles in AIED should lead to development of macrophage-targeted therapies for AIED. Future studies should be performed to elucidate the pathogenesis of immune-mediated sensorineural hearing loss and develop novel therapies for AIED.