Objective: This study explored the relationship between macrophage migration inhibitory factor (MIF) gene polymorphism (-173G/C) and glucocorticoid sensitivity in sudden sensorineural hearing loss (SSNHL).
Methods: A total of 120 patients with SSNHL were divided into a glucocorticoid-sensitive group and a glucocorticoid-resistant group. A group of 93 healthy individuals served as the control group. Serum MIF levels of the participants were measured and MIF genotyping was performed.
Results: The frequency of the MIF -173C allele was significantly higher in glucocorticoid-sensitive patients than in glucocorticoid-resistant patients. Serum MIF levels were significantly higher in SSNHL patients than in healthy controls, and higher in the glucocorticoid-sensitive group than in the glucocorticoid-resistant group of SSNHL patients, which was unexpected. Compared with patients with the GG genotype, patients with the -173C allele (GC and CC genotypes) had significantly higher levels of serum MIF and superoxide dismutase activity and lower levels of tumor necrosis factor-α and malondialdehyde.
Conclusion: The MIF -173G/C polymorphism is associated with glucocorticoid sensitivity in SSNHL patients. The C allele can result in higher MIF production, reduced oxidative stress, and greater glucocorticoid sensitivity.
Keywords: Sudden sensorineural hearing loss (SSNHL); glucocorticoid; glucocorticoid sensitivity; macrophage migration inhibitory factor (MIF); oxidative stress; polymorphism.