Abstract 13492: Glial Fibrillary Acidic Protein, a Sensitive and Specific Marker in Serum for the Identification of Intracerebral Hemorrhage in Acute Stroke Patients: Results of Improved Assay Performance
OBJECTIVES: The prognosis of acute stroke has been improved by the use of very early therapeutic interventions. Biochemical markers that could allow a rapid and accurate diagnosis differentiating between intracerebral hemorrhage (ICH) and ischemic stroke (IS) have recently been identified. This study was designed to evaluate plasma concentrations of glial fibrillary acidic protein (GFAP) in acute stroke patients and the accuracy for distinguishing ICH from IS using a current-generation sensitive assay.
METHODS: This prospective case control study enrolled in 35 controls and 33 stroke patients. ICH (n = 6) and IS (n = 24) were diagnosed using brain imaging. Blood samples were taken from each stroke patient at admission (mean122 minutes after stroke symptom onset) and measured by ELISAs, using an ultra-sensitive assay detecting breakdown products to GFAP (Banyan Biomarkers, Inc., Alachua, Fl).
RESULTS: Levels of GFAP in serum were significantly increased in ICH compared to control subjects and IS (median, 2.25 vs 0.06 vs 0.07 ng/ml, P<0.0001 and P=0.0002, respectively). GFAP concentrations in IS patients were not significantly different compared to controls (p=0.12). ROC curve analyses showed high sensitivity and specificity in differentiating between ICH and IS (AUC = 0.99; cut off=0.33 ng/ml, sensitivity 100% specificity 96%) (Figure). Concentrations of GFAP did not correlate with time to sample withdrawal. GFAP values in ICH were almost significantly correlated with the NIHSS score on admission (r = 0.9, p = 0.08).
CONCLUSIONS: Our pilot study indicates that plasma GFAP could be a reliable biomarker of intracerebral hemorrhage in acute stroke, accurately distinguish between ICH and IS and thereby facilitate the hyperacute delivery of stroke therapies. In addition, these findings support the incremental value of newer, more sensitive assays in stroke patients. Further investigations in a large cohort of patients are needed.
- © 2011 by American Heart Association, Inc.