Blood levels of TNF-α, IL-10, and IL-12 in idiopathic sudden sensorineural hearing loss
ABSTRACT OBJECTIVES/HYPOTHESIS: To investigate the blood levels of TNF-α, IL-10, and IL-12 in the idiopathic sudden sensorineural hearing loss patients, and the change of these cytokine levels after treatment. STUDY DESIGN: Prospective clinical trial. METHODS: Twenty-three patients with idiopathic sudden sensorineural hearing loss and 20 healthy people were selected as study and control groups. Blood samples for TNF-α, IL-10, and IL-12 were taken before treatment and 6 weeks after treatment. The study group was given combined treatment including dexamethasone, heparin, pentoxifyline, vitamin B1, and B6 for 10 days, and was divided into two groups: treatment responders and treatment nonresponders. The treatment responders group was also divided into three groups according to most accepted criteria for improvement in the literature. Audiograms were taken before treatment and 6 weeks after treatment to determine the response to the treatment. RESULTS: There was no significant difference between pre- and posttreatment values of IL-10 and IL-12 in all study groups (P > 0.05). There was also no significant difference between pre- and posttreatment values of TNF-α in treatment responders (P > 0.05). Treatment nonresponders had more elevated posttreatment values of TNF-α than pretreatment values (P < 0.05). CONCLUSION: IL-10 and IL-12 may not play a critical role in idiopathic sudden sensorineural hearing loss. But our data supports the role of TNF-α in the pathophysiology of idiopathic sudden sensorineural hearing loss, and TNF-α receptor blockers may have benefits in these patients. LEVEL OF EVIDENCE: 3B. Laryngoscope, 2013.
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ABSTRACT: Exogenous tumor necrosis factor-alpha (TNF-α) plays a role in auditory hair cell death by altering the expression of apoptosis-related genes in response to noxious stimuli. Little is known, however, about the function of TNF-α in normal hair cell physiology. We, therefore, investigated the cochlear morphology and auditory function of TNF-α-deficient mice. Auditory evoked brainstem response showed significantly higher thresholds, especially at higher frequencies, in 1-month-old TNF-α(-/-) mice as compared to TNF-α(+/-) and wild type (WT); hearing loss did not progress further from 1 to 4 months of age. There was no difference in the gross morphology of the organ of Corti, lateral wall, and spiral ganglion cells in TNF-α(-/-) mice compared to WT mice at 4 months of age, nor were there differences in the anatomy of the auditory ossicles. Outer hair cells were completely intact in surface preparations of the organ of Corti of TNF-α(-/-) mice, and synaptic ribbon counts of TNF-α(-/-) and WT mice at 4 months of age were similar. Reduced amplitudes of distortion product otoacoustic emissions, however, indicated dysfunction of outer hair cells in TNF-α(-/-) mice. Scanning electron microscopy revealed that stereocilia were sporadically absent in the basal turn and distorted in the middle turn. In summary, our results demonstrate that TNF-α-mutant mice exhibit early hearing loss, especially at higher frequencies, and that loss or malformation of the stereocilia of outer hair cells appears to be a contributing factor.Journal of the Association for Research in Otolaryngology 08/2013; 14(6). DOI:10.1007/s10162-013-0410-3 · 2.55 Impact Factor