Cochlin in autoimmune inner ear disease: is the search for an inner ear autoantigen over?

Definition: Autoimmune inner ear disease (AIED) is characterised by a rapidly progressive, often fluctuating, bilateral sensorineural hearing loss over a period of weeks to months. It is an uncommon disease accounting for less than 1% of all cases of hearing impairment or dizziness. The diagnosis is often missed and this impacts on the prognosis as the condition responds well to steroids and immunosuppressants if recognised early.

Lacuna in knowledge: No useful specific test for autoimmunity affecting the inner ear exists.

Objective of study: To gather evidence regarding cochlin in AIED.

Methodology: Systematic review of human studies and animal experimental studies on inner ear antigens was undertaken.

Search strategy: We searched MEDLINE (1965-2012), and Pubmed for relevant studies. A combination of key words for inner ear, autoimmunity (autoimmune, immune mediated) and cochlin were used.

Results: A number of antigens have been implicated in autoimmune inner ear disease. Cochlin is a major component of the extracellular matrix in the inner ear and a promising candidate. We present evidence in literature on the role of this protein in the pathogenesis of autoimmune inner ear disease.