Although traumatic brain injury (TBI) can be extremely difficult to evaluate, measuring specific biomarkers in blood may enable more accurate assessment of patient prognosis, according to the results of a study published Wednesday in Lancet Neurology.
The study, funded by the National Institutes of Health (NIH), found that biomarkers present in the blood on the day of a TBI can accurately predict a patient's risk of death or severe disability six months later.
Although additional studies are needed to reproduce the results, the findings indicate that blood-based biomarkers may help clinicians and researchers better predict patient outcomes after TBI, the NIH said in a statement.
The study also concluded that elevated levels of two proteins help predict how a person will recover from a TBI, providing important information to determine appropriate care, according to Abbott, the maker of the two tests used by researchers to detect the biomarkers.
Researchers conducting the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study examined levels of glial fibrillary acidic protein (GFAP) and ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) -- proteins found in glial cells and neurons, respectively -- in nearly 1,700 patients with TBI.
They used two Abbott concussion tests: its i-Stat TBI Plasma test, a U.S. Food and Drug Administration-cleared rapid test that runs on a portable analyzer, and the firm's core laboratory Architect instrument.
GFAP and UCH-1 are currently used to aid in the detection of TBI. Elevated levels in the blood on the day of the TBI are linked to brain injury visible with neuroimaging.
The i-Stat TBI Plasma test is indicated for the measurement of levels of biomarkers associated with brain injury in the bloodstream to assist in determining the need for a CT scan of the head. The test is used to help evaluate mild TBI and is only available for use on the firm's i-Stat Alinity instrument, a portable blood analyzer.
TRACK-TBI is an observational study aimed at improving understanding and diagnosis of TBIs to develop successful treatments.
The study team measured the biomarkers in blood samples taken from patients with TBI on the day of their injury and then evaluated their recovery six months later. Participants were recruited from 18 high-level trauma centers across the U.S.; more than half had suffered TBI as the result of a road traffic accident.
The study showed that GFAP and UCH-L1 levels on the day of injury were strong predictors of death and unfavorable outcomes, such as vegetative state or severe disability requiring daily assistance to function, NIH said in a statement, adding that individuals with biomarker levels among the highest fifth were at greatest risk of death in the six months post-TBI, with most occurring within the first month.
The new study suggests that GFAP and UCH-L1 levels may also help in predicting recovery, particularly among patients with moderate to severe TBI, and the biomarkers improved the accuracy of current prognostic models, the NIH said.
The researchers found that the predictive value of the biomarkers was strongest for patients with moderate to severe TBI. However, the biomarkers did not accurately predict who would experience incomplete recovery -- moderate disability but able to live independently -- at six months, the NIH added.