Alterations in Cerebrospinal Fluid Apolipoprotein E and Amyloid β-Protein after Traumatic Brain Injury

There is evidence that apolipoprotein E (apoE) and amyloid β-protein (Aβ), which are implicated in the pathology of chronic neurodegenerative disorders, are involved in the response of the brain to acute injury; however, human in vivo evidence is sparse. We conducted a prospective observational study to determine the magnitude and time-course of alterations in cerebrospinal fluid (CSF) apoE and Aβ concentrations after traumatic brain injury (TBI), and the relationship of these changes to severity of injury and clinical outcome. Enzyme linked immunosorbant assay (ELISA) was used to assay apoE, Aβ1-40 and Aβ1-42 in serial CSF samples from 13 patients with TBI and 13 controls. CSF S100B and tau were assayed as surrogate markers of brain injury. There was a significant decrease in CSF apoE (p < 0.001) and Aβ (p< 0.001) after TBI contrasting the observed elevation in CSF S100B (p < 0.001) and tau (p < 0.001) concentration. There was significant correlation (r = 0.67, p = 0.01) between injury severity and the d...