Correlations of MIF polymorphism and serum levels of MIF with glucocorticoid sensitivity of sudden sensorineural hearing loss

Abstract

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.