Immunological Damage to the Inner Ear: Current and Future Therapeutic Strategies

Abstract

There is considerable evidence to suggest that hearing and vestibular function can be influenced by immunity in the inner ear. While immunity can protect against infections of the labyrinth, immune response also has the capacity to damage the delicate tissues of the inner ear. Antigenic challenge of the inner ear of sensitized animals leads to rapid accumulation of leukocytes, antibody production, hearing loss and tissue damage. Moreover, a number of systemic autoimmune disorders include hearing loss and vertigo as part of their constellation of symptoms. It also appears that autoimmune damage can exist as an entity confined to the labyrinth. Immune disorders of the inner ear are of special interest since they are among the few forms of hearing loss that are currently amenable to medical treatment. In addition, recent developments in understanding the intracellular pathways that participate in damage to the inner ear provide new opportunities for pharmacotherapy of immune-mediated disorders of hearing and balance.

Sudden Pediatric Hearing Loss

“…It was suggested that adding intratympanic steroids to systemic steroid treatment might magnify the effectiveness of systemic steroids by increasing the steroid concentration in the middle ear (20,29). It was suggested that combining systemic and intratympanic steroids could yield greater hearing improvements compared use of systemic steroids alone (31).…”

Inner ear drug delivery for auditory applications

“…Encouraging results have been shown with methotrexate [94]. Ryan et al suggested a treatment of high dose prednisone with the addition of methotrexate if relapse occurred when the steroid was tapered [8]. Improvements in treatment may be facilitated by local delivery for both SSNHL and AIED.…”

“…In humans, these cells do not regenerate, and loss is often followed by secondary degeneration of auditory neurons. Scientists and clinicians are making progress in understanding the molecular mechanisms associated with cochlear and auditory nerve degenerative processes [7] and in finding agents that can minimize degeneration and facilitate repair [8, 9]. These insights offer the potential for development of novel and precise drug treatments.…”

Inner ear drug delivery via a reciprocating perfusion system in the guinea pig

“…Agents have been identified that can minimize degeneration and facilitate repair [4,[8][9][10][11][12]14]. Moreover, the extraordinary progress that has been made in defining the genes involved in a number of human genetic forms of deafness [15,16] offers hope for gene-transfer [1,17] and molecular [18] approaches to treat these diseases.…”