Research Reports - Glial fibrillary acidic protein as a biomarker in severe traumatic brain injury patients
Crit Care. 2015 Oct 12;19(1):362. doi: 10.1186/s13054-015-1081-8.
Lei J(1,)(2), Gao G(3,)(4), Feng J(5,)(6), Jin Y(7,)(8), Wang C(9,)(10), Mao
Q(11,)(12), Jiang J(13,)(14).
INTRODUCTION: Glial 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.
METHODS: We 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.
RESULTS: A 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.
CONCLUSIONS: Serum 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.