Autoimmune Ear Disease Research Articles

Factors influencingcollagen-induced autoimmune ear disease

In 1981, the authors described a type II collagen-induced autoimmune ear disease (CIAED) model. The purpose of this study was to gather further evidence that this is a sound animal model to use in evaluating inner ear diseases. The temporal bone lesions of CIAED in Lewis and Wistar rats were characterized by the presence of sensorineural hearing loss with mild atrophy of the organ of Corti and spiral ganglion degeneration, vestibular dysfunction with vacuolar degeneration of the crista ampullaris, otospongiosis-like lesions in the tympanic annules, cochlear vasculitis, and eustachian tube disease. Both cellular and humoral immune responses to type II collagen were demonstrated. The induction of ear lesions depends on many factors. In general, animals immunized with antigens in complete Freund's adjuvant showed relatively more severe lesions than animals immunized with antigens in incomplete Freund's adjuvant, but the duration of the immunization seems to be a more important factor in reproducing severe lesions. The strain and the source of the animals are also important factors in autoimmune inner ear diseases, as is the condition of the host animals. Subclinical or clinical mycoplasma infection in the rat markedly reduced the incidence and severity of lesions in type II collagen-induced arthritis. Many researchers did not consider sialoductal adenovirus, widely present among laboratory rats, a lesion-producing factor in rats. Although many factors influence the induction and severity of CIAED, these animal models provide an excellent new avenue of inner ear research.

389 Induction of type II collagen autoimmune arthritis and ear disease in monkey

389 Induction of type II collagen autoimmune arthritis and ear disease in monkey

Practical versus theoretical management of autoimmune inner ear disease.

Autoimmune inner ear disease is an uncommon but distinct clinical entity. Our ignorance of the immune mediating pathways, need of further animal model experimentation, variability of laboratory test results and of patient treatment responses illustrate how poorly we understand this disorder. The purpose of this review is to compare practical vs theoretical management of autoimmune inner ear disease, based upon our current knowledge of the disease process and upon a review of clinical experience at the Cleveland Clinic Foundation. Representative case histories are presented. The following preliminary conclusions are discussed: Autoimmune inner ear disease can present as a systemic or localized otologic immune disorder. Hearing loss can begin at any age, with unilateral or bilateral sudden onset, fluctuating or progressive symptoms, with or without associated dizziness. The pathogenesis of autoimmune inner ear disease is probably multifactorial (cellular and humoral). The sensitivity and specificity of different laboratory tests vary greatly, but even the most sensitive tests may be falsely normal when symptoms are not acute or when the patient is taking immunosuppressant medication. The mainstay of autoimmune inner ear treatment is steroids: however, cytotoxic drugs are recommended when there is no response to steroid treatment. Apheresis is reserved for selected cases. Hearing improvement can be dramatic even after 2 months of profound deafness. Flare-ups of autoimmune ear disease are best managed by increasing steroid dosage or adding cytotoxic medications. Unfortunately, some patients will develop progressive hearing loss despite vigorous treatment.