GFAP and S100B are biomarkers of traumatic brain injury: an observational cohort study.

BACKGROUND: Biomarker levels in blood after traumatic brain injury (TBI) may offer diagnostic and prognostic tools in addition to clinical indices. This study aims to validate glial fibrillary acidic protein (GFAP) and S100B concentrations in blood as outcome predictors of TBI using cutoff levels of 1.5 µg/L for GFAP and 1.13 µg/L for S100B from a previous study. METHODS: In 79 patients with TBI (Glasgow Coma Scale score [GCS] ≤12), serum, taken at hospital admission, was analyzed for GFAP and S100B. Data collected included injury mechanism, age, gender, mass lesion on CT, GCS, pupillary reactions, Injury Severity Score (ISS), presence of hypoxia, and hypotension. Outcome was assessed, using the Glasgow Outcome Scale Extended (dichotomized in death vs alive and unfavorable vs favorable), 6 months post injury. RESULTS: In patients who died compared to alive patients, median serum levels were increased: GFAP 33.4-fold and S100B 2.1-fold. In unfavorable compared to favorable outcome, GFAP was increased 19.8-fold and S100B 2.1-fold. Univariate logistic regression analysis revealed that mass lesion, GFAP, absent pupils, age, and ISS, but not GCS, hypotension, or hypoxia, predicted death and unfavorable outcome. Multivariable analysis showed that models containing mass lesion, pupils, GFAP, and S100B were the strongest in predicting death and unfavorable outcome. S100B was the strongest single predictor of unfavorable outcome with 100% discrimination. CONCLUSION: This study confirms that GFAP and S100B levels in serum are adjuncts to the assessment of brain damage after TBI and may enhance prognostication when combined with clinical variables.

Glial and neuronal proteins in serum predict outcome after severe traumatic brain injury.

OBJECTIVE: To study the ability of glial (glial fibrillary acidic protein [GFAP] and S100b) and neuronal (neuron specific enolase [NSE]) protein levels in peripheral blood to predict outcome after severe traumatic brain injury. METHODS: Eighty-five patients with severe traumatic brain injury (admission Glasgow Coma Score [GCS] < or = 8) were included. Blood samples taken at the time of hospital admission were analyzed for S100b, GFAP, and NSE. Data collected included demographic and clinical variables. Outcome was assessed using the Glasgow Outcome Scale (GOS) at 6 months post injury. RESULTS: The median serum levels of S100b, GFAP, and NSE were raised 18.3 fold (S100b), 4.6 fold (GFAP), and twofold (NSE) compared to normal reference values. S100b, GFAP, and NSE serum levels correlated significantly with the injury severity score and CT findings but not with age, sex, or GCS. S100b, GFAP, and NSE levels were significantly higher in patients who died or had a poor outcome 6 months post injury than in those who were alive or had good outcome. S100b level >1.13 microg/L was the strongest predictor of death with 100% discrimination, but GFAP (>1.5 microg/L) and NSE (>21.7 microg/L) levels also strongly predicted death (adjusted odds ratios 5.82 [for GFAP] and 3.91 [for NSE]). S100b, GFAP, and NSE all strongly predicted poor outcome (adjusted odds ratios 5.12 [S100b], 8.82 [GFAP], and 3.95 [NSE]). CONCLUSIONS: These results suggest that determination of serum levels of glial and neuronal proteins may add to the clinical assessment of the primary damage and prediction of outcome after severe traumatic brain injury.

Protein S-100B, neuron-specific enolase (NSE), myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP) in cerebrospinal fluid (CSF) and blood of neurological patients.

In this study, data about protein S-100B, neuron-specific enolase, myelin basic protein and glial fibrillary acidic protein in cerebrospinal fluid and blood of patients with an acute or chronic progressive neurological disorder with brain damage are reviewed. Especially in disorders with acute brain damage, determination of these proteins in CSF and blood can be helpful to establish structural and/or functional brain damage to determine severity and prognosis of the disease process and to monitor treatment effects.

Peri-operative levels of s-100 protein in serum: marker for surgical manipulation and postoperative complications.

Although minimally invasive neurosurgical techniques are highly sophisticated nowadays, almost any operative procedure causes an inevitable surgical trauma to the brain. As a consequence unfavorable functional outcomes are not rare. Intraoperative biochemical monitoring can be helpful first to detect but also to prevent brain damage. We investigated if serum S-100 protein (S-100) levels are a reliable marker for the extent of acute cerebral damage caused by surgical trauma or postoperative complication. S-100 is present in the cytosol of glial cells. This protein leaks into the extracellular space after cell damage and can be detected both in the cerebrospinal fluid (CSF) and serum. To determine S-100 protein levels, serum samples from 20 patients with various intracranial tumors were collected before surgery, and at one day, as well as at seven days after surgery. It was hypothesised that the size of the tumor-brain contact surface (TBCS) was closely related to the dimension of the surgical trauma. TBCS was measured from radiological imaging. The pre- and postoperative (day 1 and day 7) clinical condition of each patient was assessed. The S-100 levels were correlated with the TBCS and the clinical condition. Levels of S-100 on day 1 and day 7 were significantly higher as compared with levels on day 0 ( p = 0.02, respectively p = 0.01). There was a significant relationship between rise of S-100 level and worsening of clinical condition between day 0 and day 1 ( p = 0.001). Also a significant positive relationship between TBCS and the level of S-100 could be found on day 1 and on day 7 ( R = 0.71, p = 0.0009, respectively R = 0.73, p = 0.004). Furthermore, a significant relationship between the rise of S-100 level between day 0 and day 1, as well as between day 0 and day 7, and TBCS could be documented ( R = 0.61, p = 0.01, respectively R = 0.64, p = 0.005). In conclusion, serum S-100 levels are a reliable marker for acute or recent CNS damage caused by neurosurgical manipulation or as a result of secondary postoperative complications. Therefore, intraoperative monitoring of serum S-100 levels seems very promising. In such a setting the negative effects of surgical manipulation can be measured instantaneously, which should bring the neurosurgeon to change his strategy. As a consequence the surgical trauma can be minimized and functional outcome can be optimized.