Association of the final hearing result, in patients with sudden hearing loss, to the response to glucocorticoids in vitro

Abstract

Introduction: Sudden hearing loss (SHL) is rare and its etiopathogenesis is still not clear. Corticosteroid therapy is of choice based on expert recommendations due to its theoretical effects and no based on proved clinical efficacy. Objectives: To assess whether there is a correlation between the final auditory outcome of patients with SHL treated with corti­costeroids and the in vitro response of their leukocytes to corticosteroids, measured as di­fferences in the relative expression of glucocorticoid receptor target genes. Material and Method: Case-control (total recovery and not recovered respectively) study of patients with SHL treated with corticosteroids at Clinical Hospital Universidad de Chile between 2017 and 2019. DNA was obtained and stored in the Biobanco de Tejidos y Fluidos de la Universidad de Chile (BTUCH). Peripheral blood mononuclear leukocytes were purified and cultured and then exposed to hydrocortisone. The difference in the relative expression of target genes (GFBP1, CAT, HSD17B12, APOA2), by Q-RTPCR was determined. Re­sults: Thirty-five patients were recruited, 24 were included for the analysis: 11 cases and 12 controls, with and average age of 54.9 and 50.,8 years respectively, homogeneous sex distribution. There was no statistically significant difference in the relative expression of the target genes, upon in vitro exposure to corticosteroids, between both groups. Conclusion: In our study, model and evaluation system, no effects of corticosteroids were evidenced. With a larger number of patients, other target genes or other study protocols, we cannot rule out that differences could be detected.