Glial fibrillary acidic protein as a biomarker in severe traumatic brain injury patients: a prospective cohort study

Abstract

IntroductionGlial fibrillary acidic protein (GFAP) may serve as a serum marker of traumatic brain injury (TBI) that can be used to monitor biochemical changes in patients and gauge the response to treatment. However, the temporal profile of serum GFAP in the acute period of brain injury and the associated utility for outcome prediction has not been elucidated.MethodsWe conducted a prospective longitudinal cohort study of consecutive severe TBI patients in a local tertiary neurotrauma center in Shanghai, China, between March 2011 and September 2014. All patients were monitored and managed with a standardized protocol with inclusion of hypothermia and other intensive care treatments. Serum specimens were collected on admission and then daily for the first 5 days. GFAP levels were measured using enzyme-linked immunosorbent assay techniques. Patient outcome was assessed at 6 months post injury with the Glasgow Outcome Scale and further grouped into death versus survival and unfavorable versus favorable.ResultsA total of 67 patients were enrolled in the study. The mean time from injury to admission was 2.6 hours, and the median admission Glasgow Coma Scale score was 6. Compared with healthy subjects, patients with severe TBI had increased GFAP levels on admission and over the subsequent 5 days post injury. Serum GFAP levels showed a gradual reduction from admission to day 3, and then rebounded on day 4 when hypothermia was discontinued with slow rewarming. GFAP levels were significantly higher in patients who died or had an unfavorable outcome across all time points than in those who were alive or had a favorable outcome. Results of receiver operating characteristic curve analysis indicated that serum GFAP at each time point could predict neurological outcome at 6 months. The areas under the curve for GFAP on admission were 0.761 for death and 0.823 for unfavorable outcome, which were higher than those for clinical variables such as age, Glasgow Coma Scale score, and pupil reactions.ConclusionsSerum GFAP levels on admission and during the first 5 days of injury were increased in patients with severe TBI and were predictive of neurological outcome at 6 months.

Protein Biomarkers and Neuroproteomics Characterization of Microvesicles/Exosomes from Human Cerebrospinal Fluid Following Traumatic Brain Injury

“…Various biomarkers can be detected in the CSF and serum depending on the blood brain barrier (BBB) integrity after TBI. The biomarkers for astroglial injury in the brain are S100B and GFAP [26]. These two markers are found to be elevated in the CSF and serum after TBI and have a good predictive power for prognosis.…”

Ubiquinol treatment for TBI in male rats: Effects on mitochondrial integrity, injury severity, and neurometabolism

“…* Significantly different from Saline-TBI [Color figure can be viewed at wileyonlinelibrary.com] identifying successful therapeutic approaches to reduce TBI secondary injury (Di Battista et al, 2015). GFAP is an intermediate filament protein specific for astrocytes, and increased GFAP immunoreactivity is a sensitive astrocyte injury biomarker (Cikriklar et al, 2016;Lei et al, 2015;Mondello et al, 2016). GFAP protein is rapidly released into biofluids following cortical injury (Foerch et al, 2012;Y.…”

Biomarkers of Traumatic Brain Injury: Temporal Changes in Body Fluids

“…In 24- and 48-h samples, GFAP was detectable in a smaller number of patients, and the levels were only slightly elevated. A more recent study (Lei et al, 2015), which followed the levels of GFAP for 0–5 days after the injury, reported that the peak was detected at admission (0.5–4 h). Žurek and Fedora (2012) monitored children that had TBI, and they also found the highest levels of GFAP in the admission samples drawn <12 h after injury.…”