Role of Immune System in the Pathogenesis of Sudden Deafness

Yeo, Sang Won; Park, Yong Soo; Kim, Que Chic; Chang, Ki Hong

Abstract

To evaluate the immunological role in the etiopathogenesis of sudden deafness, sera from 44 patients with sudden sensorineural hearing loss were analyzed by 1) immunologic screening tests such as erythrocyte sedimentation rate(ESR), C-reactive protein(CRP), immunoglobulin(IgG, IgM) levels, complement(C3, C4) levels, autoantibody(rheumatoid factor, anti-DNA antibody, antinuclear antibody) levels, cryoglobulin and FTA-ABS 2) Western blotting immunoassay against cow's inner ear proteins 3) viral marker assay(serum IgG and IgM titer against cytomegalovirus, herpes simplex virus, varicella-zoster virus, measles virus, mumps virus and rubella virus). Thirteen(29.5%) of 44 patients displayed positive responses on immunologic screening tests. Significantly higher incidences of immunological abnormalities were found in the parameters such as levels of IgG, ESR, IgM and anti-nuclear antibody. Of 41 patients whose sera were analyzed by Western blot against fresh bovine inner ear antigen preparation, nobody showed the antibody against 68kD protein, and 1(2.4%), 4(9.8%), and 4(9.8%) had antibody which reacted with 60kD, 50kD and 33-35kD protein. On viral marker assay, 8(44.4%) of 18 patients showed positive IgG titers against herpes simplex virus, cytomegalovirus, varicella-zoster virus, measles virus, mumps virus and rubella virus. But any of 10 patients did not show significant IgM titers against those viruses. Statistical analysis revealed a significant correlation between the results of immunologic screening tests and the age of the patients(p<0.05 by chi-square), but no correlations with other clinical parameters such as sex, bilaterality, initial hearing level, and recovery(p>0.05 by chi-square respectively). There was no correlation between the results of viral marker assay(IgG) and recovery(p>0.05 by chi-square). The results suggest that viral infection may play a role in development and progress of sudden deafness, while the immunologic disorder may not affect the etiopathogenesis of sudden deafness.