[Blood biomarkers of mild traumatic brain injury in 2026]

Mild traumatic brain injury is a common reason for presentation to emergency departments, where management relies heavily on cerebral computed tomography (CT-scan), a radiological examination that is both radiation-emitting and overused. The measurement of blood biomarkers of cerebral origin provides a complementary tool to reduce this reliance. This systematic review provides a comprehensive analysis of the literature on protein S100B and the combination of glial fibrillary acidic protein and carboxy-terminal ubiquitin hydrolase L1, covering everything from their biochemistry to their pre-analytical, analytical and diagnostic performance. S100B, a long-established biomarker, has been described in recent reviews as offering excellent negative predictive value but requiring early sampling (< 3 hours) and lacking specificity, particularly in older patients. The combination of glial fibrillary acidic protein and carboxy-terminal ubiquitin hydrolase L1, with a wider diagnostic window (< 12 hours), was the subject of recent meta-analyses attributing performance similar to that of S100B. In children, specific reference values for the three biomarkers have recently been established; however, their diagnostic use has not yet been validated. New biomarkers (neurofilamant light, interleukin 6 and exosomes)and a personalized medicine approach offer promising prospects for refining their role in decision-making algorithms.