Circulating microRNAs as biomarkers in pediatric epilepsy: A longitudinal cohort study

Epilepsy is the most common chronic neurological disorder in children, and approximately one third of patients develop drug-resistant seizures. Reliable biomarkers are needed to improve diagnosis, prognostic assessment, and treatment monitoring. This study evaluated four circulating microRNAs-miR-15a-5p, miR-106b-5p, miR-146a-5p, and miR-152-3p-as potential diagnostic and prognostic biomarkers in pediatric epilepsy.

A total of 122 pediatric patients with epilepsy and 29 age- and sex-matched healthy controls were prospectively enrolled at Bambino Gesù Children's Hospital (Rome) between 2022 and 2025. Clinical variables included epilepsy type, etiology, seizure frequency, electroencephalography, magnetic resonance imaging, and comorbidities. Serum miRNAs were measured by reverse transcription quantitative polymerase chain reaction and normalized using the 2^-ΔΔCt method, accounting for hemolysis. Nonparametric tests (Mann-Whitney, Kruskal-Wallis, Wilcoxon) were used for comparisons. Forty-three patients were reevaluated after ≥12 months to assess longitudinal expression.

All four miRNAs were significantly upregulated in children with epilepsy compared to controls (p < .05). miR-146a-5p expression differed among etiological groups, being higher in structural compared with genetic or unknown etiologies (p = .014). Both miR-15a-5p and miR-106b-5p correlated with seizure frequency, showing greater expression in patients with monthly-to-daily seizures than in those with sporadic seizures or seizure-free patterns (p = .004 and p = .017). No association was found with antiseizure medications, intellectual disability, or psychiatric comorbidities. Longitudinal analysis showed a significant increase in miR-15a-5p and miR-106b-5p at follow-up (p < .01), independent of clinical outcome, whereas miR-146a-5p remained stable over time. These findings suggest that miR-15a-5p and miR-106b-5p reflect ongoing epileptic activity, whereas miR-146a-5p may relate to underlying pathophysiology rather than seizure dynamics.

Circulating miRNAs represent promising, minimally invasive biomarkers in pediatric epilepsy. miR-146a-5p may aid etiologic classification, whereas miR-15a-5p and miR-106b-5p could serve as dynamic indicators of disease burden and treatment response, supporting biomarker-driven precision approaches in epilepsy care.