Case Report: Tocilizumab in pediatric febrile infection-related epilepsy syndrome.

Background and purpose: We describe the clinical characteristics and the therapeutic effect of tocilizumab with Febrile Infection-Related Epilepsy Syndrome (FIRES). FIRES is characterized by super refractory status epilepticus (SRSE) in previously healthy children, following a febrile illness that manifests between 2 weeks and 24 hours prior to the onset of seizure. Methods: We collected and summarized the clinical data of two pediatric patients with FIRES and compare with those described previously in the literature. Results: Elevated levels of IL-6 were observed in the two patient's blood samples. Patient 1 consented to receive tocilizumab on the 58th day of the disease progression, resulting in transient relief of seizures. Throughout the follow-up period, the patient remained unconscious and consistently experienced intermittent seizures. Patient 2 was administered tocilizumab on the 7th day of the disease course. During the six-month follow-up, no seizures were observed and no significant cognitive decline. Up to date, 7 patients of pediatric FIRES treated with tocilizumab have been reported. The clinical symptoms of the patients were relatively consistent, characterized by focal seizures and status epilepticus as the primary manifestations. Serum IL-6 may exhibit elevated or normal, whereas cerebrospinal fluid IL-6 demonstrated a significant elevation, indicating a lack of concordance. Conclusion: Now little has been known about the administration of tocilizumab in pediatric FIRES. We posit that early administration of tocilizumab (within 3 weeks from disease onset) positively impacts the treatment of FIRES.