The Food and Drug Administration on Wednesday approved a first-ever blood test to detect the telltale signs of serious brain injury, bringing to fruition a long quest to make the diagnosis of concussions simpler and more precise.
After deliberations that took less than six months, the FDA approved the marketing of the Banyan Brain Trauma Indicator to aid the evaluation of concussions in adults. The speedy approval of such a blood test, after it was assigned the FDA designation of a "breakthrough" product, is expected to drive down the number of CT scans performed on patients who seek emergency-room care for a possible concussion, reducing both costs and patients' exposure to radiation.
The new test identifies two brain-specific proteins that appear in the blood within 12 hours after a brain injury. Levels of these two proteins — Ubiquitin Carboxy-terminal Hydrolase-L1 and Glial Fibrilliary Acidic Protein — released from the brain into the blood can help predict which patients may have brain lesions visible by CT scan and which won't.
Test results currently can be available within three to four hours. But Henry L. Nordhoff, chairman and chief executive officer of San Diego-based Banyan Biomarkers, told The Times on Wednesday that his company is working with the Defense Department to shorten that turn-around time to under an hour.
As the company brings on two companies to produce a smaller, faster blood-testing instrument, Nordhoff predicted that within two years, the assay will be available for rapid use in ambulances, emergency departments and in athletic training rooms.
The urgency with which the FDA reviewed and approved the new test was born of military necessity. As traumatic brain injuries mounted during the U.S. conflicts in Iraq and Afghanistan, the armed forces have urgently sought a blood test capable of predicting quickly whether a blow to the head has likely caused bleeding or bruising in the brain. The development of the new blood test, as well as the clinical trials reviewed by the FDA, were largely underwritten by the U.S. Army Medical Research and Materiel Command.
Lt. Col. Kara Schmid, project manager for the Army's Neurotrauma and Psychological Health Project Management Office, said Wednesday that the newly-approved assay "will provide a remarkable capability for the way we evaluate and care for our service members with TBI."
Far larger, however, will be the test's impact on civilian victims of brain trauma. The Centers for Disease Control and Prevention has estimated that in 2013, there were roughly 2.8 million emergency department visits, hospitalizations and deaths in the U.S. related to traumatic brain injury, or TBI.
Of these cases, TBI contributed to the deaths of nearly 50,000 people.
But knowing when a traumatic brain injury may require intensive follow-up care is an inexact science. About three-quarters of TBIs that occur each year are assessed as mTBIs or concussions, which will probably resolve with rest. But the remainder may have bruising, bleeding or swelling in the brain, and need a CT scan to locate, monitor and possibly treat the injury.
Currently, many in the larger group of concussion sufferers get CT scans to rule out more serious injury. In addition to the expense — a CT scan of the brain averaged about $1,200 in 2015 — an average CT scan of the head exposes a patient to about two millisieverts of radiation — about the equivalent of 100 to 200 chest X-rays.
For adults, the result can be a slightly increased risk of developing cancer down the road. And for children, whose bodies are smaller and whose brains are still developing, the widening use of CT scans has raised particular alarms.
So, weeding out those who could benefit from a CT scan from those who probably won't is important. And that's where Banyan's blood test can help.
In a clinical study conducted at several sites in Europe and North America, researchers gathered 1,947 individual blood samples from adults with suspected mTBI/concussion. They compared the blood test's performance in predicting the need for a CT scan with actual CT scan results.
The Brain Trauma Indicator was able to predict the presence of intracranial lesions on a CT scan 97.5% of the time and those who did not have intracranial lesions on a CT scan 99.6% of the time. The FDA judged that the test could reliably predict the absence of intracranial lesions, and predicted it would rule out the need for a CT scan in at least one-third of patients suspected of having mild traumatic brain injury.
Because of the U.S. military's role in the new test's development, Nordhoff noted that clinical trials have enrolled adults only. That limitation in research data dictated the FDA's approval of the blood test's marketing to adults.
"I think there will be some off-label usage" in children with TBI, said Nordhoff, referring to physicians' legal use of products in different ways or on different populations than those for which the products have been approved by the FDA. "But we are planning to do another study in adolescents," he added.
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