Blood‐based biomarkers and traumatic brain injury—A clinical perspective

Abstract

Blood‐based biomarkers are promising tools to complement clinical variables and imaging findings in the diagnosis, monitoring and outcome prediction of traumatic brain injury (TBI). Several promising biomarker candidates have been found for various clinical questions, but the translation of TBI biomarkers into clinical applications has been negligible. Measured biomarker levels are influenced by patient‐related variables such as age, blood‐brain barrier integrity and renal and liver function. It is not yet fully understood how biomarkers enter the bloodstream from the interstitial fluid of the brain. In addition, the diagnostic performance of TBI biomarkers is affected by sampling timing and analytical methods. In this focused review, the clinical aspects of glial fibrillary acidic protein, neurofilament light, S100 calcium‐binding protein B, tau and ubiquitin C‐terminal hydrolase‐L1 are examined. Current findings and clinical caveats are addressed.

Blood biomarkers for traumatic brain injury: A narrative review of current evidence

“…Though tau is mostly found in the brain, some extracranial sources exist such as in the liver, kidney and testis ( Morris et al, 2011 ). It is identified as a neurodegenerative biomarker, ( Jack et al, 2019 ; Kim et al, 2018 ) and has been widely investigated for the development of neuronal and axonal pathology following TBI, ( Neselius et al, 2013 ) although its half-life in blood after TBI is not established ( Posti and Tenovuo, 2022 ). Tau serum levels peak at 12–24 h, and decline relatively slowly ( Rubenstein et al, 2017 ; Randall et al, 2013 ).…”

Evaluation of Serum NLRC4 as a Potential Prognostic Biochemical Marker in Humans with Severe Traumatic Brain Injury: A Prospective Cohort Study

“… 5 Intriguingly, biochemical biomarkers have recently emerged as an indispensable tool in decision-making of sTBI. 6 , 7 …”

“…5 Intriguingly, biochemical biomarkers have recently emerged as an indispensable tool in decision-making of sTBI. 6,7 Neuroinflammatory response accompanies sTBI. 8 Inflammasome, an intracellular multi-protein complex, harbors inflammatory potentials and is involved in secondary brain injury after trauma.…”

Special issue on blood biomarkers in neurology

“…The field is moving towards a greater use of blood tests-such as for instance a combination of glial acidic protein (GFAP) and ubiquitin carboxyterminal hydrolase L1 (UCH-L1)-in predicting outcome. 3 Another use of blood biomarkers could be assessment of disease burden in clinical follow-up. For instance, GFAP levels seem to indicate severity in certain neuropathies.…”

“…In TBI, biochemical blood markers are already used to assess whether a mild head trauma has caused a mild traumatic brain injury (TBI) indicating a need for imaging. The field is moving towards a greater use of blood tests—such as for instance a combination of glial acidic protein (GFAP) and ubiquitin carboxy‐terminal hydrolase L1 (UCH‐L1)—in predicting outcome 3 . Another use of blood biomarkers could be assessment of disease burden in clinical follow‐up.…”