Background
Brevican,
neurocan,
tenascin-C and
tenascin-R are
extracellular matrix proteins present in brain that show increased expression in experimental animal models of
brain injury. However, little is known about the dynamics of these
proteins in human body fluids, such as cerebrospinal fluid (CSF) and serum, after
traumatic brain injury (TBI). The aims of this study were to investigate if matrix
proteins in CSF and serum are associated with functional outcome following
traumatic brain injury, if their concentrations change over time and to compare their levels between brain injured patients to controls. Methods In total, 42
traumatic brain injury patients, nine healthy controls and a contrast group consisting of 38 idiopathic
normal pressure hydrocephalus patients were included.
Enzyme-linked
immunosorbent assays (ELISAs) were used to measure the concentrations of
proteins. Results Increased concentrations of
brevican,
tenascin-C and
tenascin-R in CSF correlated with unfavourable outcome, with stronger outcome prediction ability compared to other
biomarkers of brain tissue injury. CSF
brevican,
tenascin-R and serum
neurocan gradually decreased with time (p = 0.04, p = 0.008, p = 0.005, respectively), while serum
tenascin-C (p = 0.01) increased. CSF concentrations of
brevican,
neurocan and
tenascin-R (only in time point 3) after TBI were lower than in the idiopathic
normal pressure hydrocephalus group (p < 0.0001, p < 0.0001, and p = 0.0008, respectively). In serum,
tenascin-C concentration was higher and
neurocan lower compared to healthy controls (p = 0.02 and p = 0.0009). Conclusions These findings indicate that levels of
extracellular matrix proteins are associated with clinical outcome following TBI and may act as markers for different pathophysiology than currently used
protein biomarkers.