ABSTRACT NUMBER: ESOC2026A189 THE CLINICAL UTILITY OF MEASURING CIRCULATING GFAP IN SEVERE STROKE

Abstract Background and aims Stroke is a global health concern, requiring early and accurate diagnosis for effective treatment. Differentiating between ischemic stroke and hemorrhagic stroke is critical, as treatment strategies differ significantly. While neuroimaging is the gold standard for differential diagnosis of stroke code patients, blood biomarkers could be a promising and cost-effective diagnostic method for earlier diagnosis in the prehospital setting, where neuroimaging is unavailable. Studies demonstrate that the biomarker glial fibrillary acidic protein (GFAP) can distinguish ischemic and hemorrhagic stroke with high specificity, though sensitivity varies based on sampling timing and assay methodology. This narrative review explores the potential of GFAP as a diagnostic biomarkern severe strokes, and in identifying large vessel occlusions (LVOs). Methods We performed a narrative review by searching electronic databases, such as PubMed and Google Scholar, to identify relevant articles published up to July 2025. The search used combinations of the keywords “glial fibrillary acidic protein”, “stroke”, “blood biomarker”, and “diagnosis”. Articles were screened for relevance based on title and abstract, followed by full-text review. Results While studies suggest a correlation between higher GFAP levels and stroke severity in hemorrhagic stroke, evidence for this in ischemic stroke is inconclusive. Combining GFAP with clinical stroke scales and additional biomarkers has shown promise in identifying LVO. Conclusions Future research should focus on refining the diagnostic role of GFAP in severe strokes, optimizing sample timing, and including large cohorts representing the full spectrum of stroke severities. Conflict of interest Megan Gjordeni: nothing to disclose. Jakob Pansell: nothing to disclose. Eric P. Thelin: nothing to disclose. Michael V. Mazya: nothing to disclose. Kaveh Pourhamidi: nothing to disclose. Perttu J. Lindsberg: nothing to disclose. Olli S. Mattila: nothing to disclose. Charith Cooray: nothing to disclose.