Early Biomarkers in the Detection of Traumatic Brain Injury

TOPLINE:

The levels of biomarkers GFAP, UCH-L1, and MAP-2 are significantly elevated within 30 and 60 minutes of traumatic brain injury (TBI), thereby facilitating early diagnosis. GFAP demonstrates the highest diagnostic accuracy for detecting intracranial lesions and predicting the need for neurosurgical intervention (NSI) and the occurrence of clinically important early outcomes (CIEO).

METHODOLOGY:

• The researchers analyzed 804 prehospital patients (mean age, 41 years; 74.2% men) with hemodynamic stability and suspected moderate to severe TBI across 20 centers and 39 emergency medical systems in North America between May 2015 and March 2017.
• Blood samples were collected within 30 minutes (n = 375) and 60 minutes (n = 563) of injury and levels of GFAP, UCH-L1, and MAP-2 were measured.
• The outcomes included the presence of intracranial lesions on CT scan, the need for NSI within 24 hours of injury, and the occurrence of CIEO within 7 days of injury.
• The patients were treated with tranexamic acid (TXA) or placebo. However, TXA has previously been shown to have no effect on GFAP, UCH-L1, and MAP-2 levels in TBI.

TAKEAWAY:

• Significant increases in biomarker levels were observed with worsening diffuse injury on CT at both time points.
• Among patients whose blood samples were taken within 30 minutes, 56.5% had CT lesions, 16.3% underwent NSI, and 30.0% had CIEO. For those with samples collected within 60 minutes, the respective values were 56.1%, 16.9%, and 30.6%.
• GFAP showed the highest diagnostic accuracy for detecting CT lesions within 30 minutes ( area under the receiver operating characteristic curve [AUC], 0.88; 95% CI, 0.85-0.92) and within 60 minutes (AUC, 0.89; 95% CI, 0.86-0.92), outperforming MAP-2 and UCH-L1. The combined use of the biomarkers was not more effective than using GFAP alone in achieving improved outcomes.
• A GFAP level of 30 pg/mL within 30 minutes provided 98.1% sensitivity for detecting CT lesions, whereas levels above 6200 pg/mL were associated with a high risk of requiring NSI and the occurrence of CIEO.

IN PRACTICE:

” In this cohort study of prehospital patients with TBI, GFAP, UCH-L1, and MAP-2 measured within 30 and 60 minutes of injury were significantly associated with traumatic intracranial lesions and diffuse injury severity on CT scan, 24-hour NSI, and 7-day CIEO. GFAP had the strongest independent association, with sensitivities of 98%-99% and specificities of 18%-36% for estimating outcomes,” the authors wrote.

SOURCE:

The study was led by Linda Papa, MDCM, MSc, Department of Emergency Medicine, Orlando Regional Medical Center, Orlando, Florida. It was published online on September 4, 2024, in JAMA Network Open.

LIMITATIONS:

A substantial proportion of the patients in this study was men (74.2%), which may limit the generalizability of the findings to women. The study did not examine the specific clinical circumstances surrounding NSIs, such as intracranial pressure monitoring or the use of drainage devices. Withdrawal from life-sustaining measures was not considered in the study.

DISCLOSURES:

The study was funded by grants from the National Heart, Lung, and Blood Institute and the Department of Defense Emergency Management Response System. Two authors reported receiving personal fees or grants from various sources and serving on advisory boards outside the scope of this study.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.