GFAP/UCH-L1 as a Biomarker for Rapid Assessment of Mild TBI in Emergency Departments

BACKGROUND Traumatic brain injury (TBI) is a major cause of mortality and disability in Western countries. The diagnosis of TBI mainly involves computed tomography (CT), and Glasgow Coma Scale assessment. As frequent use of CT is associated with excessive radiation exposure, discovery of a biomarker for TBI could reduce unnecessary head CT scans. Thus, the main aim of this study was to evaluate a TBI assessment kit measuring glial fibrillary acidic protein (GFAP) and ubiquitin carboxyl-terminal hydrolase-L1 (UCH-L1), for its suitability to diagnose mild TBI in emergency departments (EDs). MATERIAL AND METHODS The records of 123 patients with head injuries admitted to the Clinical Emergency Department of the Regional Specialist Hospital in Olsztyn, Poland between December 2023 and August 2024, were prospectively analyzed. Patients underwent CT, were classified as isolated head injury (IHI, n=61) or injuries beside TBI (non-IHI, n=62), and tested for serum GFAP and UCH-L1 concentrations using immuno-chemical chemiluminescence. RESULTS No significant differences in GFAP and UCH-L1 concentrations were observed between IHI and Non-IHI patients. While CT showed brain alterations in 7 patients, GFAP and UCH-L1 concentrations were above the threshold in 6 patients with brain injury confirmed by CT. The sensitivity of the TBI test was 83.3%, with specificity 29.1%. The sensitivity of GFAP was 83.3% and that of UCH-L1 was 50.0%, with specificities of 37.9% and 65.0%, respectively. CONCLUSIONS Based on our study, further investigations are required before GFAP and UCH-L1 blood test samples can be recommended as an adjunct to CT scans as a standard procedure.