Exploratory analysis of circulating miRNA-100 and its association with eosinophilia in pediatric allergic rhinitis.

Introduction

Allergic rhinitis (AR) is a chronic inflammatory disorder of the upper airways characterized by a Th2-skewed immune response, elevated immunoglobulin E (IgE) levels, and eosinophilia. Increasing evidence suggests that microRNAs (miRNAs) may contribute to the regulation of immune pathways in AR; however, their role in pediatric populations remains insufficiently understood. Aim: The aim of this exploratory study was to evaluate serum expression of miRNA-100, miRNA-155, and miRNA-224 in children with AR and to assess their associations with immunological and clinical parameters. Materials and methods: A total of 21 children were included (12 with AR and 9 non-atopic controls). Serum levels of selected miRNAs, cytokines (IL-4, IL-5, IL-6, IL-10, IL-13), eosinophil counts, and total IgE were analyzed.

Results

MiRNA-100 expression was higher in the AR group compared with controls; however, this difference did not reach statistical significance (p = 0.051). No significant differences were observed for miRNA-155 or miRNA-224. In unadjusted analyses, correlations between miRNA-100 and eosinophil parameters were not statistically significant. In partial correlation analysis adjusted for age and sex, a moderate association between miRNA-100 and absolute eosinophil count was observed (rho = 0.498; p = 0.042). Among cytokines, only IL-10 levels were significantly lower in the AR group, while a substantial proportion of measurements for other cytokines were below the detection limit, limiting interpretability.

Conclusions

Given the small sample size and lack of statistical significance in primary comparisons, these findings should be considered preliminary and hypothesis- generating. The observed association between miRNA-100 and eosinophilia may warrant further investigation in larger, well-characterized cohorts.