Researchers from University of Michigan had identified a protein that triggered the antibodies in patients suffering from autoimmune sensori-neural hearing loss or AISNHL.
In the August issue of the Archives of Otolaryngology - Head and Neck Surgery, researchers reports results from a study of 63 people with rapidly progressing hearing loss in Michigan, Pennsylvania and Indiana, and 20 people with normal hearing. The patients were suspected of having an autoimmune cause for their hearing loss, and all received steroids, but they hadn't been formally diagnosed.
The researchers found that more than half of the hearing-loss patients had antibodies against a protein found in the inner ear, called IESCA for inner-ear supporting cell antigen. This is a sign their immune systems recognized it as foreign.
In all, 28 of the 63 patients experienced improvement in their hearing after steroid treatment, and 35 did not. But the vast majority, 89 percent, of those who improved had a positive immunofluorescence test for an antibody to IESCA, said the researchers. The results strongly suggest that a direct test for antibodies could accurately predict which patients will regain hearing with steroid treatment.
The new findings also may be important to people with systemic autoimmune disorders such as lupus or rheumatoid arthritis. Such people may be prone to losing all or part of their hearing due to an overzealous autoimmune reaction. All eight-study participants who had systemic autoimmune diseases showed signs of antibodies against IESCA. Six of them regained hearing after steroid treatment.