Outcome biomarkers following severe traumatic brain injury.

Trauma is the leading cause of death of people from 1 to 44 years of age. Traumatic brain injury is the main determinant for mortality and morbidity caused by trauma. Outcome prediction is one of the major problems related to severe traumatic brain injury because clinical evaluation has an unreliable predictive value and complicates identification of patients with higher risk of developing secondary lesions and fatal outcome. That is why, there is considerable interest in development of biomarkers that reflect the severity of brain injury and correlate with mortality and functional outcome. Proteins S100B and neuron specific enolases are among the markers most studied for this purpose, however some studies are investigating glial fibrillary acidic protein, creatinine phospokinase, isoenzime B, myelin basic protein, plasma desoxiribonucleic acid, heat shock protein 70, von Willebrand factor, metalloproteinases and brain-derived neurotrophic factor, among others. Evidence suggests that inflammation, oxidative stress, excitotoxicity, neuroendocrine responses and apoptosis play an important role in the development of secondary lesions. Markers involved in these processes are being studied in traumatic brain injury. We reviewed these biomarkers, some of which present promising results for future clinical application.