Serum Glial Fibrillary Acidic Protein Is a Highly Specific Biomarker for Traumatic Brain Injury in Humans Compared With S-100B and Neuron-Specific Enolase

Background: Serum glial fibrillary acidic protein (GFAP) is a specific predictor of brain damage and neurologic outcome in patients with traumatic brain injury (TBI). In this study, serum GFAP, S-100B, and neuron-specific enolase (NSE) were compared in the same samples from severe trauma patients to assess their ability to predict abnormalities detectable on head computed tomography (CT). Methods: This study was a retrospective analysis at a single university emergency center. Thirty-four trauma patients were included. Serum samples were collected from the patients for 3 days. Serum GFAP, S-100B, and NSE concentrations were measured with enzyme-linked immunosorbent assays and compared in patients with and without TBI, as evaluated by head CT. Results: Serum GFAP, S-100B, and NSE were significantly higher in the TBI patients than in the non-TBI patients (p < 0.05 for each protein). The receiver operating characteristic curves for TBI were compared for the three biomarkers for 3 days. Serum GFAP on day 1 had the largest area under the receiver operating characteristic curve (0.983), with 88.9% sensitivity and 100% specificity. Conclusions: Serum GFAP has remarkable diagnostic value for TBI, defined by abnormal head CT findings, in prehospital-triaged patients with severe trauma.