Mechanistically informed circulating biomarkers are associated with acquired epilepsy after neonatal brain injury

BACKGROUND: Acute provoked neonatal seizures are a major risk factor for acquired epilepsy, yet clinicians lack reliable tools to identify neonates at highest risk. Preclinical data implicate innate immune activation and neuronal injury as key drivers of epileptogenesis, suggesting blood-based biomarkers could provide mechanistic insight and prognostic utility. We sought to identify biomarkers of epileptogenesis in neonates with acute provoked seizures after brain injury using multicenter cohorts. METHODS: We conducted a prospective, multi-cohort analysis across two independent studies. NSR-RISE enrolled neonates with EEG-confirmed acute provoked seizures of diverse etiologies. The HEAL trial enrolled neonates with hypoxic-ischemic encephalopathy; analyses were limited to those with seizures. Plasma proteins were quantified 48-96 h after seizure onset. Associations with acquired epilepsy by 24-months were evaluated using log-link models with robust standard errors and false-discovery rate correction (FDR < 0.05). Significant proteins were added to models including established clinical predictors (≥ 3 days of EEG seizures and abnormal neurological examination at discharge). Exploratory pathway enrichment used KEGG databases. NSR-RISE participants also underwent plasma microRNA (miRNA) sequencing with integrative pathway analyses. RESULTS: Among 35 neonates in NSR-RISE, 7 (20%) developed epilepsy; among 40 neonates in HEAL, 6 (15%) developed epilepsy. Across both cohorts, neonates with epilepsy had higher concentrations of the pro-inflammatory cytokine IL-1β and the neuronal injury marker UCHL1 compared to those without epilepsy. Growth hormone (GH), measured only in NSR-RISE, was decreased in neonates with epilepsy. Incorporation of biomarkers improved prognostic accuracy for epilepsy beyond clinical features alone (Area under the precision-recall curve (AUPRC) 0.30 (95%CI, 0.28-0.32) versus 0.91 (95%CI, 0.89-0.92); p < 0.001). Pathway enrichment analyses implicated innate immune signaling, including TLR/IL1/NF-κB-related and MAPK-associated IL-17 signaling. miRNA profiling identified 11 species differentially expressed between neonates with and without epilepsy, including brain-enriched miRNAs. Network analysis identified a co-expression module enriched for let-7f-5p and miR-146a-5p targeting TLR/IL1/NF-κB, MAPK, and JAK/STAT pathways. CONCLUSIONS: Across two cohorts, mechanistically informed biomarkers were associated with acquired epilepsy after neonatal seizures. IL-1β, UCHL1, and GH reflect inflammation, neuronal injury, and impaired trophic signaling, while circulating miRNAs provide complementary mechanistic insight. Findings support a translational biomarker panel and highlight inflammation as a biologically plausible therapeutic target.