Circulating microRNAs as potentially new diagnostic biomarkers of idiopathic sudden sensorineural hearing loss

Background: Early detection of inner ear cell damage can reduce the chances of permanent damage to hearing ability. However, current inner ear cell damage detection methods can detect damage only after the patient has lost hearing ability. MicroRNA expression levels in circulating systems are affected in diseases or conditions arising from the distant lesions. Therefore, detection of circulating microRNA expression levels could be one of the best ways to obtain information on inaccessible lesion sites. Aims/objectives: This study aims to establish a method for monitoring idiopathic sudden sensorineural hearing loss (ISSNHL) by analyzing circulating microRNA expression levels. 21 ISSNHL patients and 24 healthy controls were enrolled. Material and methods: Real-time quantitative polymerase chain reaction was performed for detecting expression levels of circulating microRNAs. Results: Among eight circulating microRNAs, expression levels of five circulating microRNAs significantly differed between ISSNHL patients and healthy controls. circulating microRNA expression levels correlates with treatment outcomes and hearing ability. Conclusions and significance: Using methods combining the evaluation of miR-183, miR-210, miR-18b, and miR-23a cut-off values identified in ISSNHL patients and healthy controls during receiver operating characteristic curve analysis, sensitivity and specificity of 80.95% (17/21) and 87.50% (21/24) were obtained, respectively.