Brain-originated peptides as possible biochemical markers of traumatic brain injury in cerebrospinal fluid post-mortem examination

The release of brain-originated peptides such as tau protein (MAPT), S-100β, neurofilament light chain (NFL), and glial fibrillary acidic protein (GFAP) into the cerebrospinal fluid (CSF) has been positively correlated with head injuries in clinical and basic research. In this study, we wanted to examine if selected CSF biomarkers (GFAP, NFL, and myelin basic protein – MBP) of head injury may be useful in post-mortem examination and diagnosis of forensic cases. The study was carried out using cases of head injury and cases of sudden death (cardiopulmonary failure, no injuries of the head as control group) provided by forensic pathologists at the Department of Forensic Medicine, Medical University of Warsaw. Cerebrospinal fluid was collected within 24 h after death using suboccipital puncture. The concentration of these peptides was compared using an enzyme-linked immunosorbent assay (ELISA). Brain specimens (frontal cortex) were collected during forensic autopsies. Sections were stained immunohistochemically against GFAP, MBP, NF, and amyloid-β precursor protein (APP). As a result we documented that elevated levels of CSF, GFAP, MBP, and NFL should be considered a marker for severe and moderate traumatic brain injury. Elevated levels of those peptides combined with a negative APP staining point to their role as markers of head trauma with a shorter time span than APP (manner of minutes).