Exploratory analysis of glial fibrillary acidic protein and ubiquitin C-terminal hydrolase L1 in management of patients with mild neurological symptoms undergoing head computed tomography scan at the emergency department: a pilot study from a Croatian tertiary hospital.

Background: Diagnostic accuracy of glial fibrillary acidic protein (GFAP) and ubiquitin C-terminal hydrolase L1 (UCH-L1) in identification of intracranial abnormalities detected by computed tomography (CT) in mild traumatic brain injury (mTBI), and in patients with mild neurological symptoms not caused by head trauma but suspected with a neurological disorder, was examined.

Methods: GFAP and UCH-L1 were determined using the chemiluminescence immunoassays on the Alinity i analyzer (Abbott Laboratories).

Results: Significantly higher GFAP (median 53.8 vs 25.7 ng/L, P < .001) and UCH-L1 (median 350.9 vs 153.9 ng/L, P < .001) were found in mTBI compared to non-head trauma patients. In mTBI diagnostic sensitivity (Se) and specificity (Sp) for the combination of GFAP and UCH-L1 were 100% and 30.9%, respectively, with area under the curve (AUC) 0.655. GFAP alone yielded Se 85.7%, Sp 41.8%, and AUC 0.638, while UCH-L1 yielded Se 57.1%, Sp 56.4%, and AUC 0.568. In non-head trauma patients, the combination of GFAP and UCH-L1 showed Se 100%, Sp 87.9%, and AUC 0.939, while GFAP alone demonstrated Se 100%, Sp 90.9%, and AUC 0.955.

Conclusions: If these results are reproduced on a larger sample, GFAP and UCH-L1 may reduce CT use in patients with mild neurological symptoms after systemic causes exclusion and neurologist's evaluation.