CSF and Plasma Amyloid-β Temporal Profiles and Relationships with Neurological Status and Mortality after Severe Traumatic Brain Injury

The role of amyloid-beta (A beta) neuropathology and its significant changes in biofluids after traumatic brain injury (TBI) is still debated. We used ultrasensitive digital ELISA approach to assess amyloid-beta(1-42) (A beta 42) concentrations and time-course in cerebrospinal fluid (CSF) and in plasma of patients with severe TBI and investigated their relationship to injury characteristics, neurological status and clinical outcome. We found decreased CSF A beta 42 levels in TBI patients acutely after injury with lower levels in patients who died 6 months post-injury than in survivors. Conversely, plasma A beta 42 levels were significantly increased in TBI with lower levels in patients who survived. A trend analysis showed that both CSF and plasma A beta 42 levels strongly correlated with mortality. A positive correlation between changes in CSF A beta 42 concentrations and neurological status as assessed by Glasgow Coma Scale (GCS) was identified. Our results suggest that determination of A beta 42 may be valuable to obtain prognostic information in patients with severe TBI as well as in monitoring the response of the brain to injury.