A Literature review of traumatic brain injury biomarkers

Research into TBI biomarkers has accelerated rapidly in the past decade owing to the heterogeneous nature of TBI pathologies  and management, which pose challenges to TBI evaluation, management, and prognosis. TBI biomarker proteins resulting  from axonal, neuronal, or glial cell injuries are widely used and have been extensively studied. However, they might not pass  the blood-brain barrier with sufcient amounts to be detected in peripheral blood specimens, and further might not be detectable in the cerebrospinal fuid owing to fow limitations triggered by the injury itself. Despite the advances in TBI research,  there is an unmet clinical need to develop and identify novel TBI biomarkers that entirely correlate with TBI pathologies on  the molecular level, including mild TBI, and further enable physicians to predict patient outcomes and allow researchers to  test neuroprotective agents to limit the extents of injury. Although the extracellular vesicles have been identifed and studied  long ago, they have recently been revisited and repurposed as potential TBI biomarkers that overcome the many limitations  of the traditional blood and CSF assays. Animal and human experiments demonstrated the accuracy of several types of  exosomes and miRNAs in detecting mild, moderate, and severe TBI. In this paper, we provide a comprehensive review of  the traditional TBI biomarkers that are helpful in clinical practice. Also, we highlight the emerging roles of exosomes and  miRNA being the promising candidates under investigation of current research.