Brain Injury Blood Test Breakthrough?

An international study claims that a simple blood test can accurately predict the presence and the severity of traumatic brain injury (TBI). Not only would the availability of such a test in the clinical lab reduce the costs of unnecessary radiological examinations, but it would also allow a quicker patient categorization and provide valuable support for treatment decision-making.

The rationale behind the test is this: glial fibrillary acidic protein breakdown products (GFAP-BDP) are proteins found in the central nervous system (CNS), which can be detected in the serum using sandwich ELISA. These proteins are known to be associated with certain neurological disorders, including TBI. So an international team, headed by Paul McMahon of the University of Pittsburgh Medical Center, US, set about validating the use of this test in the diagnosis of intracranial injury in a broad population of patients with a positive clinical screen for head injury.

To do this, blood samples were analyzed in multiple centers, in over 200 patients aged 16–93 who were being treated for suspected TBI (1). Blood was drawn and tested for the GFAP-BDP biomarker within 24 hours of the patients presenting at a clinic, alongside CT scans. Patients were also offered a follow-up MRI within two weeks of the original injury.

The results were encouraging: elevated GFAP-BDP was significantly associated with the presence of visible TBI on CT scans, and the severity of injury. The test provided an advantage over clinical screening alone, preventing unnecessary scans by 12–30 percent, and predicted brain pathology on CT scan with an accuracy of 81 percent, higher than that of standard clinical predictors, such as pupillary response and Glasgow Coma Scale score.

Radiography is a central part of diagnosing brain injury, but scans can be expensive, and pose risks to the patient. The study authors are hopeful the test could become a useful addition to methods of neurological examination, and believe that “early measurement of GFAP-BDP can contribute to more accurate diagnosis and triage of TBI patients, decreasing the number of unnecessary CT scans and allowing more tailored management of the brain injury.”