ABSTRACT NUMBER: ESOC2026LB84 SERUM GFAP AFTER FIRST-ONSET TRANSIENT ISCHEMIC ATTACK: A PILOT CASE CONTROL STUDY

Abstract Background and aims Brief focal cerebral ischemia may injure astrocytes or disturb the blood brain barrier even when imaging shows no infarction. Glial fibrillary acidic protein (GFAP) is released after astrocytic injury. Its behavior after a first-ever transient ischemic attack (TIA) remains unclear. Methods Fourteen consecutive patients with clinically diagnosed first-onset TIA (symptoms under 24 hours; MRI negative for infarction) and fourteen neurologically healthy volunteers were enrolled. Standard diagnostic work-up was performed in all patients. Blood samples were obtained within 24 hours of symptom onset. Serum GFAP was measured using a validated chemiluminescent immunoassay. Group comparisons used nonparametric tests. Diagnostic accuracy was assessed by ROC analysis. Functional outcome at six months was recorded using the modified Rankin Scale. Results TIA patients were older and carried more vascular risk factors than controls. Median serum GFAP was higher in the TIA group at 3.25 ng/mL (interquartile range 4.10) compared with 1.13 ng/mL (interquartile range 1.68) in controls (p = 0.002). The ROC area under the curve was 0.83 (95% confidence interval 0.67 to 0.99). A cutoff near 2.3 ng/mL yielded sensitivity around 75% and specificity around 78%. Within the TIA group, women showed higher GFAP concentrations than men. GFAP was not associated with six-month functional outcome. Conclusions These findings suggest that first-onset TIA is accompanied by measurable astrocytic injury or transient barrier dysfunction. The sample is small. Groups were unmatched. Sampling was limited to a single time point. Larger studies are required. Conflict of interest