Favorable outcomes with early interleukin-6 receptor blockade in severe acute necrotizing encephalopathy of childhood

Abstract Background Outcome in severe acute necrotizing encephalopathy of childhood is poor, with high mortality (30%) and moderate to severe disability in survivors despite the use of intravenous corticosteroids or immunoglobulins. Increased blood interleukin 6 level correlates with poor outcome. Methods We report the early use of tocilizumab, a monoclonal antibody against the interleukin 6 receptor, in three patients (aged five, eight, and 10 years) with severe acute necrotizing encephalopathy. Results All three patients experienced a rapid neurological deterioration associated with febrile viral illnesses and met criteria for severe acute necrotizing encephalopathy with a high risk for death or severe disability. Intravenous methylprednisolone and tocilizumab were administered at 18 to 32 hours of encephalopathy in addition to supportive medical therapy. No side effects were observed with this therapeutic strategy. The two patients with influenza A(H1N1)pdm09 virus-related acute necrotizing encephalopathy had a short illness with excellent clinical and radiological recovery. The patient with influenza B virus-related acute necrotizing encephalopathy and florid hemorrhagic brain lesions had a slow recovery with eventual mild disability despite focal encephalomalacia on follow-up neuroimaging. Conclusions The early use of interleukin 6 blockade in acute necrotizing encephalopathy is safe and may have a role in improving outcomes and preventing disability.