Blood test predicts intracranial injuries after trauma
Ubiquitin C-terminal hydrolase-L1 (UCH-L1) and glial fibrillary acidic protein (GFAP) may emerge as biomarkers for detecting intracranial injuries after a trauma, a recent prospective study suggests.
The study results also support the clinical use of UCH-L1 and GFAP test to rule out the need for head CT scan in patients presenting with traumatic brain injury (TBI) at emergency departments. [Lancet 2018, doi: 10.1016/S1474-4422(18)30231-X]
Detection of intracranial injuries relies on head CT scan, which is overused and resource intensive. There are also health concerns with regards to the high radiation dose with head CT scans.
In the present study, a group of researchers from Germany, Hungary and the US enrolled 1,977 patients presenting to emergency departments with suspected, non-penetrating TBI. These patients also had a Glasgow Coma Scale score of 9–15, and had undergone head CT scan and blood collection for UCH-L1 and GFAP test within 12 hours after the injury.
Among 1,959 patients with analysable data, 6 percent had CT-detected intracranial injuries. A total of 66 percent of the patients had positive UCH-L1 and GFAP test results.
UCH-L1 and GFAP test had a sensitivity of 0.976 (95 percent confidence interval [CI], 0.931 to 0.995) and a negative predictive value (NPV) of 0.996 (95 percent CI, 0.987 to 0.999) for detection of intracranial injury. Only three of 1,959 patients had false-negative results. The test had a specificity and positive predictive value of 0.364 and 0.095, respectively.
“The results support the routine use of the UCH-L1 and GFAP test in emergency departments to rule out unnecessary head CT scans with a very low false-negative rate,” the investigators suggested.
“Notably, the majority of patients presenting with mild TBI like concussion do not have visible intracranial injuries on CT scans. As UCH-L1 and GFAP biomarker test requires only blood collection and is reliable in predicting the absence of intracranial injuries, we are hopeful of its future role in ruling out the need for CT scans in these patients,” said investigator Dr Peter Biberthaler of the Technical University of Munich, Germany.