Observational Study of Tocilizumab in Children With Febrile Infection-Related Epilepsy Syndrome

This study aimed to assess the efficacy and safety of using tocilizumab in children with febrile infection-related epilepsy syndrome (FIRES) and explore tocilizumab-related changes in interleukin (IL)-6 levels.

Patients with FIRES admitted to the Intensive Care Unit (ICU) of Beijing Children's Hospital were retrospectively included and categorized into tocilizumab and control groups based on whether tocilizumab was administered to compare prognostic differences and drug safety. Patients in the tocilizumab group were further classified into response (characterized by ≥ 50% reduction in seizure frequency on electroencephalogram within one-week post-treatment) and no-response groups for intergroup comparison of tocilizumab regimens and clinical outcomes. Serum and CSF IL-6 levels were collected before and after the first tocilizumab dose to analyze the dynamics.

Of 58 enrolled patients with FIRES, 23 received tocilizumab. The tocilizumab group showed higher rates of consciousness recovery and favorable Pediatric Cerebral Performance Category scores (p < 0.05). The incidence of post-FIRES epilepsy was lower in the tocilizumab group (p < 0.001). The response group (9 patients) received earlier tocilizumab treatment, had shorter mechanical ventilation and ICU durations, and experienced higher consciousness recovery rates (p < 0.05). Serum IL-6 levels increased post-treatment (p = 0.003), while CSF IL-6 levels showed a non-significant decline (p = 0.080). There was no significant difference in the rates of combined infection, liver function impairment, and total cholesterol elevation between the tocilizumab and control groups (p > 0.05).

Early tocilizumab administration may improve outcomes in patients with FIRES, with a clinically acceptable safety profile.