IL-18 and IL-37 levels in paediatric epilepsy

Background:Neuroinflammation is now widely recognized as an important factor in the development and progression of epilepsy. Interleukin-18 (IL-18), a pro-inflammatory cytokine belonging to the interleukin-1 family, has been linked to increased seizure susceptibility. In contrast, interleukin-37 (IL-37) functions as a natural suppressor of IL-18–mediated inflammatory responses. Despite this, the involvement of the IL-18/IL-37 axis in paediatric epilepsy has not yet been fully elucidated.
Objectives:The aim of this study was to evaluate serum levels of IL-18 and IL-37 and to investigate their relationship with disease severity in children with epilepsy.
Methods:The study included 117 children diagnosed with epilepsy and 53 age- and sex-matched healthy controls. Serum concentrations of IL-18 and IL-37 were measured using enzyme-linked immunosorbent assay (ELISA). Additionally, gene polymorphisms of IL-18 and IL-37 were assessed using allele-specific polymerase chain reaction.
Results:Serum levels of both IL-18 and IL-37 were significantly higher in children with epilepsy compared to controls, with the highest levels observed in patients experiencing frequent seizures (vs controls: IL-18 p = 0.0022; IL-37 p ≤ 0.0050). A strong positive correlation was found between IL-18 and IL-37 concentrations (R = 0.75, p < 0.001). No significant relationships were identified between cytokine levels and epilepsy duration, time since the last seizure, or other clinical parameters. Furthermore, no significant differences in genetic polymorphisms were observed between patients and controls.
Conclusions:These findings indicate that IL-18 and IL-37 may reflect ongoing immune activation associated with epilepsy severity and could serve as complementary biomarkers in paediatric epilepsy. To our knowledge, this is the first clinical study to evaluate serum IL-37 levels in patients with epilepsy. Further longitudinal research is needed to confirm and expand upon these results.