Increased levels of CSF heart-type fatty acid-binding protein and tau protein after aneurysmal subarachnoid hemorrhage

BACKGROUND: Heart-type Fatty Acid-Binding Protein (H-FABP) and tau protein (tau) have been shown to be novel biomarkers associated with brain injury and, therefore, they could represent a useful diagnostic tool in patients with subarachnoid hemorrhage (SAH). The goal of this study was to measure H-FABP and tau in cerebrospinal fluid (CSF) following SAH to test the hypothesis that a relationship exists between SAH severity and H-FABP/tau values. METHODS: Twenty-seven consecutive SAH patients admitted to our ICU were studied. Serial CSF samples were obtained in every patient starting on the day of SAH and daily for up to 2 weeks post-SAH. H-FABP/tau levels were measured by enzyme-linked immunosorbent assay. RESULTS: Patients with severe SAH showed significantly higher peak levels of H-FABP and tau compared to mild-SAH patients (FABP: p = 0.02; tay: p = 0.002). In addition the peak concentrations of H-FABP and tau in CSF from SAH patients correlated significantly with Glasgow Coma Scale motor score (H-FABP: Spearman r = -0.52, p = 0.006; tau: Spearman r = -0.63, p = 0.0004). Based on outcome at discharge from the hospital, patients were categorized into survivors and non-survivors. Peak concentrations of both proteins in the non-survivors group were significantly higher than in the survivors. CONCLUSIONS: H-FABP and tau CSF levels are proportional to SAH severity and may be novel biomarkers that can be used to predict the severity of outcome following clinical SAH.