RESUMEN
BACKGROUND AND OBJECTIVES: Although there are a number of reports concerned with the role of immunity in the sudden onset of progressive sensorineural hearing loss, there are only a few references dealing with the involvement of immuneme- mediated mechanism in sudden deafness. This study was performed to define the alteration of peripheral blood T lymphocyte subsets in a group of patients with sudden deafness. MATERIALS AND METHODS: The study was carried out prior to the start of and after the steroid therapy. Thirty two patients (18 men and 14 women : mean age, 43.19 years) were compared with 15 healthy control subjects (7 men and 8 women : mean age, 44 years). Patients were divided into 2 groups according to their responses to the steroid therapy. RESULTS: A decreased number of both CD4' helper cells (38.44% vs 42.36%; p < 0.05) was observed in the patient group compared with those in the control group. In the group of patients who showed good response to the steroid therapy, there was a tendency toward normalization of the CD4 (pretreatment, 34.41%; posttreatment, 43.91%) cell counts, with a slight decrease in the CD8' population (pretreatment, 20.66%: posttreatment, 19.16%). However, there was no significant increment in patients with the poorer response when there was a increase in the CD4' (pretreatment, 32.12% ; posttreatment, 38.6%) cell counts after the steroid therapy. CONCLUSION: These results demonstrate that there is significant abnormality in the subpopulations of lymphocytes in patients with sudden hearing loss, suggesting the immune system as a possible etiopathogenic factor in this entity.