Although there are a number of reports concerned with the role of immunity in the sudden onset of progressive sensorineural hearing loss, there are few references dealing with the involvement of immunemediated mechanisms in sudden deafness.
To study the phenotype of peripheral blood lymphocytes in a group of patients with sudden deafness by use of 3-color flow cytometry.
The study was carried out prior to the start of steroid therapy. Fourteen patients underwent a follow-up study once steroid therapy had been completed. Prospective analysis, case-control.
Tertiary case referral center, ambulatory and hospitalized care.
Twenty-two patients (13 men and 9 women; mean age, 45.3 years) were compared with 14 healthy control subjects (9 men and 5 women; mean age, 36 years). Patients were divided in 2 groups according to their response to steroid therapy.
Decreased numbers of both CD4+ helper cells (38.4% vs 45.5%; P=.04) and CD8+ cytotoxic cells (17.5% vs 22.3%; P=.02) were observed in patients and compared with those in the control subjects, as well as reduced numbers of CD4+CD45RA+ cells (14.4% vs 29.3%; P=.01) and CD8+CD45RA+ naive cells (18.2% vs 25.4%; P=.04). In the group of patients with a good response to steroid therapy (group 1), a tendency toward normalization of the CD4+ (pretreatment, 38.6%; posttreatment, 44.6%), CD4+CD45RA+ (pretreatment, 15.2%; posttreatment, 21.7%), and CD4+CD45RO+ (pretreatment, 21.1%; posttreatment, 18.2%) cell counts was observed, with a slight decrease in the CD8+ population (pretreatment, 18%; posttreatment, 15.7%). However, in patients with a poorer response (group 2), while there were increases in the CD4+ (pretreatment, 38%; posttreatment, 50%) and CD4+CD45RA+ (pretreatment, 12.8%; posttreatment, 16.7%) cell counts after steroid therapy, there was a significant increment in the CD4+CD45RO+ memory cell count (pretreatment, 14,1%; posttreatment, 28.5%) and low CD8+CD45RA+ counts (pretreatment, 14.6%; posttreatment, 15.5%). No differences were observed in the numbers of B or natural killer cells or in the presence of activation antigens CD25 and HLA-DR when pretreatment and posttreatment levels were compared.
These results demonstrate significant abnormalities in the subpopulations of lymphocytes in patients with sudden hearing loss, suggesting the existence of immune-mediated responses in the inner ear as possible etiopathogenic factors in this entity.Arch Otolaryngol Head Neck Surg. 1997;123:712-717
García-Berrocal JR, Vargas JA, Ramírez-Camacho RA, González FM, Gea-Banacloche JC, Vergara J, Durántez A. Deficiency of Naive T Cells in Patients With Sudden Deafness. Arch Otolaryngol Head Neck Surg. 1997;123(7):712-717. doi:10.1001/archotol.1997.01900070056009