Brain-Derived Neurotrophic Factor and Interleukin-6 Levels in the Serum and Cerebrospinal Fluid of Children with Viral Infection-Induced Encephalopathy

We investigated changes in the brain-derived neurotrophic factor (BDNF) and interleukin (IL)-6 levels in pediatric patients with central nervous system (CNS) infections, particularly viral infection-induced encephalopathy. Over a 5-year study period, 24 children hospitalized with encephalopathy were grouped based on their acute encephalopathy type (the excitotoxicity, cytokine storm, and metabolic error types). Children without CNS infections served as controls. In serum and cerebrospinal fluid (CSF) samples, BDNF and IL-6 levels were increased in all encephalopathy groups, and significant increases were noted in the influenza-associated and cytokine storm encephalopathy groups. Children with sequelae showed higher BDNF and IL-6 levels than those without sequelae. In pediatric patients, changes in serum and CSF BDNF and IL-6 levels may serve as a prognostic index of CNS infections, particularly for the diagnosis of encephalopathy and differentiation of encephalopathy types.