Interleukin 18 (IL-18) and its binding protein (IL-18BP) are increased in patients with epilepsy suggesting low-grade systemic inflammation.

•Epilepsy patients had significantly higher level of IL-18 and IL-18BP, indicating the presence of a low-grade systemic inflammation involving IL-18 in epilepsy patients.•Serum concentration of those markers was not significantly correlated with potential confounders.•The level of IL-18 and IL-18BP was not associated with clinical characteristics of the epilepsy patients.•The ratio IL-18/IL-18BP was significantly associated with medication.