Role of serum S100B as an early predictor of high intracranial pressure and mortality in brain injury: A pilot study

Objective: To investigate whether serum S100B is suitable as a sensitive biomarker for early prediction of increased intracranial pressure and mortality rates after brain injury. Design: A prospective, longitudinal study. Setting: Neurosurgical intensive care unit. Patients: Twenty-one patients with acute brain injury and 13 healthy controls. Interventions. None. Measurements and Main Results: We assessed Glasgow Coma Scale score and pupil reaction on admission and quantified serum S100B (in-house enzyme-linked immunosorbent assay) and intracranial pressure on admission and the subsequent 6 days. Serum S100B concentrations on admission and day 1 were significantly higher in patients with fatal outcome (p <.05, p <.01, respectively), with a sensitivity of 100% and a specificity of 75-83%. Patients with high serum S100B on admission had an eight-fold and on day 1 a 12-fold increased relative risk of a fatal outcome. Subsequent serum S100B values predicted the development of high intracranial pressure in patients with traumatic brain injury (p <.01). Patients with high intracranial pressure on day 5 had an 11-fold and on day 6 a nine-fold increased risk of fatal outcome. Conclusions: Serum S100B is a sensitive biomarker for early prediction of the development of high intracranial pressure and fatal outcome following acute brain injury. Monitoring S100B concentrations could contribute to early detection of patients at risk of secondary increases in intracranial pressure and subsequent mortality. This would allow earlier targeting of therapy in selected patients.