Levels of IL-1β and IL-1ra in Cerebrospinal Fluid of Human Patients after Single and Prolonged Seizures

Abstract

Background: Experimentally induced seizures are associated with increased production of inflammatory cytokines in the nervous system. Elevated cerebrospinal fluid levels of cytokine interleukin-6 (IL-6) have been found after a single generalized seizure in human patients. After prolonged seizures, levels of IL-6 have been shown to be even higher compared with single seizures. In the present study, we determined the levels of proconvulsive IL-1β and anticonvulsive IL-1ra in cerebrospinal fluid after single tonic-clonic seizures as well as after prolonged seizures. Methods: The levels of cytokines were measured using enzyme-linked immunosorbent assay. Results: We found that after single seizures, a slight increase in anticonvulsive IL-1ra levels was found; however, after prolonged partial or recurrent tonic-clonic seizures, the levels of IL-1ra were significantly elevated, together with decreased IL-1β levels. Conclusion: Our results indicate that after severe seizures, the balance between IL-1-type cytokines is changed towards a neuroprotective and anticonvulsive direction with an overproduction of IL-1ra with respect to potentially neurotoxic IL-1β. This reaction may serve as a defense mechanism of the nervous system against excitotoxic neuronal damage.