[S100B protein serum level as a biomarker of minor head injury]

S100B is a small protein selectively synthesized by cerebral astroglial cells. S100B participates physiologically in the regulation of intracellular free calcium levels, and exerts a neurotrophic activity on cerebral cells. The interest of S100B protein in clinical biology results from its physiological presence in biological fluids (cerebrospinal fluid, blood, urine) and from significant increased levels when an acute brain injury occurred, from vascular (intracranial hemorrhage, ischemic stroke) or traumatic (traumatic brain injury) origins. Thus, elevated plasma concentrations of S100B were significantly increased in patients with a minor, moderate and of course severe traumatic brain injury. By contrast, serum S100B levels remained unchanged in patients with negative craniocerebral tomography results, confirming the diagnostic value of this biomarker. A prognostic value of the biomarker in the context of minor head injury is also reported.