Serum HMGB1 and TLR4 Levels in Pediatric Drug-Resistant Epilepsy: Associations and Preliminary Discriminatory Performance

Abstract

Purpose: Drug-resistant epilepsy (DRE) in children contributes substantially to morbidity and mortality. Neuroinflammation has been implicated in epilepsy pathogenesis, particularly in treatment resistance. High-mobility group box 1 (HMGB1) and Toll-like receptor 4 (TLR4) are key mediators of inflammatory signaling. HMGB1 released during cellular stress can activate TLR4 and promote proinflammatory cytokine production. This study examined the association of serum HMGB1 and TLR4 levels with pediatric DRE and assessed their preliminary discriminatory performance.Methods: This cross-sectional study was conducted from April to December 2022 at Sardjito Hospital, Yogyakarta, Indonesia. Sixty-six children with epilepsy were consecutively enrolled and classified into drug-resistant and drug-responsive groups according to International League Against Epilepsy criteria. Serum HMGB1 and TLR4 levels were measured using a sandwich enzyme-linked immunosorbent assay.Results: Serum HMGB1 and TLR4 levels were significantly higher in the DRE group than in the drug-responsive group. Higher levels were also associated with seizure frequency >3 seizures/month, age >5 years, and abnormal neuroimaging findings. HMGB1 and TLR4 levels showed a significant positive correlation (r=0.587, P=0.001). In exploratory receiver operating characteristic analysis, HMGB1 showed an area under the curve (AUC) of 0.805 at a cutoff of 247.5 pg/mL, with 81.8% sensitivity and 60.6% specificity. TLR4 showed an AUC of 0.733 at a cutoff of 122.5 pg/mL, with 72.7% sensitivity and 51.5% specificity. The combined HMGB1–TLR4 model showed an AUC of 0.819.Conclusion: Serum HMGB1 and TLR4 levels were associated with pediatric DRE and higher seizure frequency, supporting their potential role as exploratory inflammatory biomarkers. However, their modest specificity and the single-center cross-sectional design preclude their use as standalone diagnostic tests. Larger studies with external validation are needed.