Anakinra for tocilizumab-refractory febrile infection-related epilepsy syndrome with normal IL-1β levels: a case report.

BACKGROUND

Febrile infection-related epilepsy syndrome (FIRES) is a severe epileptic encephalopathy with limited treatment options. Neuroinflammation, particularly involving IL-1β and IL-6, is a key driver. Evidence on sequential use of IL-6 receptor blockade (tocilizumab) followed by IL-1 receptor blockade (anakinra) is scarce, especially when IL-1β levels are normal.

CASE PRESENTATION: A previously healthy 6-year-old boy developed super-refractory status epilepticus six days after influenza A infection. He failed multiple antiseizure medications, anesthetics, corticosteroids, intravenous immunoglobulin, ketogenic diet, and mild therapeutic hypothermia. Cerebrospinal fluid (CSF) and serum cytokine testing showed elevated IL-6 but normal IL-1β. After initial improvement with tocilizumab, seizures relapsed. Tocilizumab retreatment and plasma exchange were ineffective. Switching to daily subcutaneous anakinra led to rapid seizure control within five days. He was weaned off anesthetics, extubated, and eventually discharged with mild cognitive dysfunction (PCPC score 2). At one-month follow-up, he had rare brief seizures and attended school.

CONCLUSION

This case demonstrates that anakinra can be effective in tocilizumab-refractory FIRES even when CSF and serum IL-1β levels are normal. Anakinra should be considered as a second-line option in selected patients, regardless of IL-1β biomarker status.