Scientists have analyzed blood samples from people who experienced acute spinal cord injuries (SCIs) and unaffected individuals, and have revealed biomarkers that can tell clinicians more about SCI severity. This data was used to create a novel blood test that predicts the likelihood that a patient will regain motor and sensory function within six months of their injury. The findings have been reported in The Journal of Clinical Investigation.
SCI affects an estimated 18,000 Americans annually, and these traumatic injuries can have a major impact on quality of life among other things. Assessing these injuries can be time consuming, costly, and challenging for patients and caregivers.
"If you have a spinal cord injury, your main question is simple: Am I going to walk again? With the new blood test, we are trying to bring a precision medicine framework to spinal cord injury with something that tells you about injury severity and can hopefully predict neurologic recovery," explained first study author Tej D. Azad, MD, M.S., neurosurgery chief resident at Johns Hopkins University School of Medicine.
Blood tests have not usually been regarded as a good way to assess SCIs. But in this work, the researchers wanted to take advantage of cell-free DNA (cfDNA), which can be found in circulation, but may sometimes arise from tumors, injury, or other problems.
"Using blood-based biomarkers for cancer diagnosis and progression has changed the practice of oncology," noted co-senior study author Nicholas Theodore, M.D., director of the Johns Hopkins Neurosurgical Spine Center. "Utilizing similar technology, this test is truly an example of personalized medicine in traumatic injury."
The scientists developed a spinal cord DNA signature from the blood samples of 50 patients with acute SCI and 25 unaffected individuals. There were higher levels of cfDNA in individuals without sensation or motor function compared to people with less severe injuries. This suggested that as spinal cord damage gets worse, there is more cfDNA in the bloodstream.
There were also four blood plasma proteins: FABP3, IL-6 and NF-H, and REST that were found at higher levels in SCI patients compared to those who were unaffected.
The blood test that was created based on this data is known as the Spinal Cord Injury Index (SCII). The researchers also confirmed that the results from SCII tests agreed completely with the severity of an injury and the conclusions that can be drawn from MRI scans and physical evaluations.
"These findings highlight the importance of a multi-analyte approach," said senior study author Chetan Bettegowda, MD, Ph.D., a Professor of Neurosurgery at Johns Hopkins University School of Medicine, among other appointments. "Combining both DNA and protein-based biomarkers improves the test performance and biological relevance."
After following up on the patients, the test was also shown to effectively predict which would experience neurologic improvement with 77% accuracy.
Now the researchers want to perform more testing and make improvements if necessary so that this test can be brought to the clinic to improve patient care.
Sources: Johns Hopkins University, Journal of Clinical Investigation
