Autoimmune hearing loss is a potentially reversible form of hearing loss defined by rapidly progressive sensorineural loss and a characteristic recovery with immunosuppressive therapy. The pathogenesis of the disorder is uncertain, but damage to inner-ear structures is thought to occur through an immune-mediated process. In this article, the authors review the current understanding of the disorder. Cogan syndrome is included as well. The authors also provide an update on treatments for autoimmune hearing loss.
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• Autoimmune sensorineural hearing loss is a well-described clinical entity that has a not fully understood pathogenesis.
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• Cogan syndrome is characterized by audiovestibular and ocular disease (interstitial keratitis).
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• Progress has been made in understanding the underlying pathophysiology, both in animal models and human patients.
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• Treatment remains aimed at controlling a likely abnormal immune response to inner-ear antigens, and study data are reviewed in this article regarding specific agents and therapeutic management approaches.
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• Classically, autoimmune sensorineural hearing loss improves with initiation of treatment, deteriorates with discontinuation of therapy, and recovers with reinstitution of treatment.
Historical note and terminology
Autoimmune sensorineural hearing loss is a well-described clinical entity with an uncertain pathogenesis. Known also as "immune-mediated sensorineural hearing loss," "autoimmune inner-ear disease," and "steroid-responsive sensorineural hearing loss," this disorder is one of only a few forms of sensorineural hearing loss that can be treated.
A relationship between autoimmune diseases and hearing loss is well recognized, with descriptions of sensorineural loss seen in such systemic autoimmune diseases as systemic lupus erythematosus (SLE), polyarteritis nodosa (PAN), granulomatous polyangiitis (GPA) (former nomenclature – Wegener granulomatosis), and rheumatoid arthritis (35). In addition, reports have also described associations with celiac disease (100), primary antiphospholipid syndrome (11; 102), Behcet disease (22), Sweet syndrome (13), ankylosing spondylitis (01), systemic sclerosis (56), sclerouveitis in the setting of HLA-B27 positivity (78), and Cogan syndrome (66). See Table 1 in the “Etiology” section for a complete listing of associated diseases.
An immune response directed against the inner ear resulting in hearing loss was first described in 1979 (62). McCabe described sensorineural hearing loss in 18 patients with a variable presentation of progressive bilateral asymmetrical sensorineural hearing loss accompanied by vestibular symptoms. These patients showed negative serologic testing, with the notable exception of a positive response to inner-ear antigens. Treatment with dexamethasone and cyclophosphamide substantially improved hearing. The distinctive clinical course, laboratory findings, and clinical response to immune therapy raised the specter of this entity to being autoimmune mediated. Subsequent literature described a characteristic clinical presentation to include rapid onset (usually unilateral), as well as a more slowly progressing form of sensorineural hearing loss (63).
A condition referred to as "steroid-responsive bilateral sensorineural hearing loss" appeared in the literature in the 1980s (48). Several patients diagnosed with idiopathic sensorineural hearing loss showed improvement in audiologic measurements following steroid therapy and subsequent deterioration of auditory sensitivity on discontinuation of treatment. These patients also revealed elevated serum levels of immune complexes that responded to steroid treatment (47). Earlier was described an immune complex-mediated disorder with features of vasculitis that targeted the inner ear and improved with glucocorticoids (98).
Although rigid diagnostic criteria for autoimmune sensorineural hearing loss are currently not defined, the hallmark features of progressive sensorineural hearing loss and steroid responsiveness are widely recognized features.