Blood-Based Biomarkers Help Predict Outcomes After TBI

A new NIH study found that biomarkers present in the blood on the day of a traumatic brain injury (TBI) can accurately predict a patient’s risk of death or severe disability 6 months later. Measuring these biomarkers may enable a more accurate assessment of patient prognosis following TBI, according to results published in Lancet Neurology.

Researchers with the Transforming Research and Clinical Knowledge in 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. 

Participants were recruited from 18 high-level trauma centers across the country. More than half (57 percent) had suffered TBI as the result of a 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. Those with biomarker levels among the highest fifth were at greatest risk of death in the 6 months post-TBI, with most occurring within the first month.

GFAP and UCH-1 are currently used to help detect TBI. Elevated levels in the blood on the day of the TBI are linked to brain injury visible with neuroimaging. In 2018, the FDA approved use of these biomarkers to help clinicians decide whether to order a head CT scan to examine the brain after mild TBI.

The new study suggests that GFAP and UCH-L1 may also help to predict recovery, particularly among 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 6 months.