Serum S-100B protein monitoring in patients with severe traumatic brain injury

Objective: S-100B protein is a promising marker of injury severity and outcome after head injury. We examined the relationship between serum S-100B concentrations and injury severity, clinical course, survival, and treatment efficacy after severe traumatic brain injury (TBI). Design and setting: Prospective observational study in a neurosurgical intensive care unit. Patients and participants: 102 adult patients with severe TBI, admitted between June 2001 and November 2003 (30 months). Interventions: Serum S-100B levels were measured by immunoluminometric technique on admission and every 24 h thereafter for a maximum of 7 days. Measurements and results: Initial S-100B levels were significantly related to pupillary status, computed tomography severity1, and 1-month survival. Cox's proportional hazard regression analysis showed that initial S-100B was an independent predictor of 1-month survival, in the presence of dilated pupils, and with increased age. Subjects with initial levels above 1 g/l had a nearly threefold increased probability of death within 1 month. Serum S-100B alteration indicated neurological improvement or deterioration. Finally, surgical treatment reduced S-100B levels. Conclusions: Serum S-100B protein reflects injury severity and improves prediction of outcome after severe TBI. S-100B may also have a role in assessing the efficacy of treatment after severe TBI.