Immunohistochemical detection of humoral autoantibodies in patients with hearing loss in the last hearing ear.

Background: An autoimmune etiology similar to the sympathetic ophthalmia ha s been discussed for sensorineural hearing loss on the last hearing ear fol lowing deafness in the first ear. In sympathetic cochleolabyrinthitis inner ear proteins are thought to be released after laterobasal fracture, which may induce an autoimmune process in the last hearing ear. Animal models hav e failed to clearly demonstrate the location of the target in the labyrinth , attacked by immunologic processes. Furthermore, it is unclear whether the humoral or cellular path-way is initiating this process. Methods and Patie nts: Serum was acquired from 15 patients with traumatic or postinflammatory unilateral deafness and slowly progressive or sudden sensorineural hearing loss on the last hearing ear. Deparaffinized sections of rat temporal bone s were incubated with patient serum and subjected to immunohistochemical ex amination. Results: A specific but heterogenous binding pattern of the laby rinth was found in 14 of 15 patients. Conclusion: Our results indicate diff erent autoantibodies in the patient serum, which may be the cause of the he aring loss. Therefore, in patients with sensorineural hearing loss on the l ast hearing ear, we recommend a therapeutic trial with corticosteroids.