Abstract WP441: Diagnostic Accuracy of Glial Fibrillary Acidic Protein and Ubiquitin Carboxy-Terminal Hydrolase-L1 for Differentiating Acute Intracerebral Hemorrhage From Ischemic Stroke

Abstract

Background: Biomarkers indicative of intracerebral hemorrhage (ICH) may help triage acute stroke patients in the pre-hospital phase. The objective of this study was to investigate whether serum levels of glial fibrillary acidic protein (GFAP) in combination with ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1) can reliably distinguish ICH from ischemic stroke. Methods: This prospective two-center study recruited patients with a clinical diagnosis of acute stroke both in the pre-hospital phase and at hospital admission (within 4 and 6 hours after symptom onset, respectively). Blood samples were analyzed for concentrations of GFAP and UCHL1 using ELISA techniques. Reference standard was the diagnosis of ICH, ischemic stroke, or stroke mimicking condition achieved after clinical work-up including brain imaging. Results: A total of 251 patients were included (mean age [±SD] 72±15 years; 5 ICH, 23 ischemic strokes and 14 stroke mimics in the pre-hospital part; and 59 ICH, 148 ischemic strokes and 2 stroke mimics in the in-hospital part). Both GFAP and UCH-L1 serum concentrations were higher in patients having ICH as compared to other diagnoses (GFAP: median 330 ng/L [interquartile range 64-7060] vs. 27.5 ng/L [14-57.25], p<0.001; UCHL1: 401 ng/L [265-764] vs. 338 ng/L [213-549.5], p=0.025). Area-under-the-curve values were 0.866 (95% CI 0.809-0.924, p<0.001) for GFAP, and 0.590 (0.511-0.670, p=0.033) for UCH-L1. Regarding overall diagnostic accuracy, UCH-L1 did not add significantly to the performance of GFAP. Conclusion: GFAP differentiates ICH from ischemic stroke and stroke mimics. A point-of-care test may improve the pre-hospital triage and treatment of acute ICH patients.