[Binding of serum immunoglobulins to human inner ear tissue in inner ear hearing loss: methodologic limits]

The immunopathological processes possibly involved in cryptogenic sensorineural hearing loss were investigated. In a pilot study the sera from 66 patients were tested by the indirect immunofluorescence technique for immunoglobulins which bind to normal human inner ear tissue. The reaction was positive in two thirds of all patients with sudden hearing loss, especially bilateral. This was mostly for IgG, and to the organ of Corti. Others have found that Corti's organ showed marked degenerative changes in cases of sudden hearing loss, examined by histology. The reaction was positive in half of the patients with progressive sensorineural hearing loss. It was noticeable that positive reactions for IgA were twice as frequent in sera of patients with progressive hearing loss than in those with sudden deafness. In a control study, the sera of ten patients were tested in parallel by the same method on histological sections of inner ears taken from four individuals. Similar results were found for the sera of two patients only. The sera of the remaining eight patients revealed very inconsistent reaction patterns. These preliminary results may indicate that temporary or permanent humoral (auto) immune mechanisms could have occurred in certain inner ear diseases. So far however reliable diagnostic methods have not been established, and not enough patients have been followed up.