Prognostic value of brain injury biomarkers in acute encephalitis/encephalopathy

Background: Acute encephalitis/encephalopathy (AEE) is a devastating cause of severe neurodevelopmental sequelae or death in children. Assessing ongoing brain injury and predicting outcomes using bedside point-of-care testing is expected to be extremely valuable. Methods: For this study, three brain injury markers, S-100B, glial fibrillary acidic protein (GFAP), and tau protein, were measured in early cerebrospinal fluid samples of children with AEE. Subjects comprised three groups: Group 1 (non-AEE control, n = 27); Group 2 (AEE with normal resolution or mild sequelae, n = 13); and Group 3 (AEE with severe sequelae or death, i.e. "poor outcome," n = 10). Results: All marker levels were significantly higher in Group 3 than in Group 1 or 2. In Group 3, only S-100B was significantly higher in non-survivors than in survivors. For scoring assessment (range: 0-3 points), the predictive accuracies of 3 points for poor outcomes in children with AEE (i.e. Group 2 and 3, n = 23) were 91% (21/23) for S-100B, 74% (17/23) for GFAP, and 78% (18/23) for tau. When the scores were summed up for S-100B, GFAP, and tau (range: 0-9 points), and for S-100B and tau (range: 0-6 points), the patients with poor outcomes were identified more accurately using the respective thresholds of 6 points and 4 points (96% (22/23) and 100% (23/23), respectively). Conclusion: Our findings suggest that combined measurement and scoring assessment of the markers, especially S-100B and tau, show promise as predictors of clinical outcomes in children with AEE.