Objective: Otitis media with effusion (OME) is a common childhood disease and the main cause of conductive hearing loss in this age group. Many factors predispose to OME but allergy is still widely disputed. The answer may lay in the molecular mechanisms of ear exudate formation and the recent studies showed miRNAs might take part in it. MiRNAs are also potent regulators of allergic response. As miRNAs are present in the middle ear, we hypothesized their expression differs between allergic and non-allergic patients and reflects the difference in pathomechanism of effusion formation between these two groups.
Materials and methods: This study aimed to establish the expression of 5 different miRNAs (miR-223-3p, miR-451a, miR-16-5p, miR-320e, miR-25-3p) in ear exudates in children diagnosed with OME. The allergy group consisted of 18 patients whereas the non-allergic group had 36 patients. MicroRNA was isolated from the middle ear fluid collected during myringotomy and transcribed into cDNA. MiRNA expression was measured with TaqMan™ MicroRNA Assays and analyzed with DataAssist software. The comparative CT method was used for calculating the relative quantification of gene expression based on the endogenous control gene expression (U6 snRNA-001973).
Results: MiR-320e expression was significantly decreased in allergic children with OME. Other studied miRNAs also showed reduced expression in allergic children, but the decrease was not significant.
Conclusions: MiRNA expression differs between children with and without allergy in the course of OME, but further studies are needed to explain the exact role of miR-320e and its target genes in OME pathology in allergic patients.
Keywords: Allergy; Asthma; Chronic inflammation; Otitis media with effusion; Rhinitis; miRNA.
Copyright © 2021. Published by Elsevier B.V.