Interferon a protein produced when the body is infected with a virus exerts a powerful immunosuppressant effect of which hearing loss is one of the major side effects (Lancet, 1994; 343: 1134-5). Now, researchers, looking at this from another angle, speculate that sudden hearing loss (SHL) may be the result of autoimmune dysfunction (Audiol, 1995; 34: 89-102; Auris Nausus Larynx, 1995; 22: 53-8).
Another study showed that nearly 40 per cent of those with SHL had autoantibodies against the inner ear (Mol Cell Biochem, 1995; 146: 157-63).Cogan syndrome, which involves damage to the ears and the eyes, can be successfully treated if caught early one of the few treatable causes of deafness. While its causes remain unknown, it is also thought to be an autoimmune disease (J Am Board Fam Pract, 1993; 6: 577-81. There is research to show that Meniere's disease (which also causes progressive deafness) may be triggered by immune system damage (Laryngoscope, 1993; 103: 1027-34).
In spite of this, there are currently no tests which can show whether hearing loss is the result of autoimmune dysfunction.