The role of two brain injury biomarkers, GFAP and UCH-L1, for the management of mTBI in the Emergency Department: an observational study.

The management of the Emergency Department (ED) of patients with mild traumatic brain injury (mTBI) is currently challenging due to its clinical heterogeneity. The most rapid method to assess brain damage is to perform a brain computed tomography (CT) scan. Stratification scores, as the Canadian CT Head Rule or the New Orleans Criteria, can be used for a quick and safe rule-out for mTBI, but scientific literature highlights how these scores are misused in real life leading to perform useless brain CT scans with radiation exposure, even in patients who do not need it. In the last years, some scientific associations have suggested the use of a biomarker to help clinicians in decision-making in this field. Given these premises, in this study we evaluated the effectiveness of two biomarkers, the glial fibrillary acidic protein (GFAP) and the ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), in predicting the necessity of performing a CT scan of the brain in the study population calculated as Negative Predictive Value (NPV) compared to CT scan reports. From January 2023, we enrolled 101 participants with mTBI who underwent a brain CT scan and blood test to assess levels of two biomarkers at the ED of Policlinico Teaching Hospital of Catania, Italy. 17 participants had a positive brain CT scan report. Of these, 13 reported an "elevated" levels of biomarkers, and 4 a "not elevated" levels leading to an NPV of 86.6%. A specialist neuroradiologist reassessed, in blind, all CT scans leading to the re-evaluation of 9 CT scans, initially reported as positive by the ED radiologist, which were then reassessed as negative. The results yielded an NPV of 100%. Our study suggests that GFAP and UCH-L1 can be effectively used in the management of patients with mTBI for a rapid and safe rule-out of the patients.