S100B blood level measurement to exclude cerebral lesions after minor head injury: the multicenter STIC-S100 French study.

BACKGROUND: S100B protein measurement in blood is proposed to exclude the presence of computed tomography (CT) lesions after minor head injury (MHI). We aimed to validate S100B as an accurate and valuable screening tool for MHI diagnosis in a large multicenter study, as well as: 1) to evaluate whether a second S100B blood level determination 3 h after the first one would be informative; 2) to compare the bioclinical performances of the two commercially available automated methods of measurement of S100B for the screening of patients. METHODS: Four thousand and thirty MHI subjects were enrolled in a prospective observational multicenter study; results for serum S100B measurement determined within 3 h after the clinical event (H0) then at H3 were compared to that of cranial CT scans performed with 6 h following the presentation to emergency department. Both the Diasorin and the Roche Diagnostics assays were systematically performed. RESULTS: Cerebral lesions on CT scan were identified with sensitivity and negative-predictive value (NPV) of 96.3% and 99.4% (Diasorin, 1 dissonant case), and of 100% and 100% (Roche Diagnostics, no dissonant case). Sensitivity and NPV at H3 appeared lower than those at H0, due to the rapid decrease in S100B levels. CONCLUSIONS: Serum S100B level on admission of patients with MHI is an accurate and useful screening tool to exclude intracranial lesions. Performing a second late S100B level determination is not informative. The two automated immunoassays appear usable in a similar manner, although the two methods are not interchangeable.

Endostatin level in cerebrospinal fluid of patients with Alzheimer's disease.

The aim of this study was to measure the level of endostatin, a fragment of collagen XVIII that accumulates in the brain of patients with Alzheimer's disease (AD), in the cerebrospinal fluids (CSF) of patients with neurodegenerative diseases. The concentrations of total protein, endostatin, amyloid-ß1-42 peptide, tau, and hyperphosphorylated tau proteins were measured by enzyme-linked immunosorbent assay in CSF of patients with AD (n = 57), behavioral frontotemporal dementia (bvFTD, n = 22), non AD and non FTD dementia (nAD/nFTD, n = 84), and 45 subjects without neurodegenerative diseases. The statistical significance of the results was assessed by Mann-Whitney and Kruskal and Wallis tests, and by ROC analysis. The concentration of endostatin in CSF was higher than the levels of the three markers of AD both in control subjects and in patients with neurodegenerative diseases. The endostatin/amyloid-ß1-42 ratio was significantly increased in patients with AD (257%, p < 0.0001) and nAD/nFTD (140%, p < 0.0001) compared to controls. The endostatin/tau protein ratio was significantly decreased in patients with AD (-49%, p < 0.0001) but was increased in bvFTD patients (89%, p < 0.0001) compared to controls. In the same way, the endostatin/hyperphosphorylated tau protein ratio was decreased in patients with AD (-21%, p = 0.0002) but increased in patients with bvFTD (81%, p = 0.0026), compared to controls. The measurement of endostatin in CSF and the calculation of its ratio relative to well-established AD markers improve the diagnosis of bvFTD patients and the discrimination of patients with AD from those with bvFTD and nAD/nFTD.

Effects of hemolysis and storage condition on neuron-specific enolase (NSE) in cerebrospinal fluid and serum: implications in clinical practice.

The concentration of neuron-specific enolase (NSE) in serum and cerebrospinal fluid (CSF) has been used as a biomarker in some cancers and, more recently, in neurodegenerative diseases. Pre-analytical conditions are very important for the quality of returned results. In this study, we evaluated the effects of storage conditions (temperature and duration of storage) and hemolysis on the concentration of NSE in serum and CSF. Our results demonstrate that samples for NSE measurement may be stored at -80 degrees C for no more than 6 months in the case of CSF and 9 months in the case of serum samples. Even invisible hemolysis may increase NSE levels in samples. Consequently, an index of hemolysis should be determined before deciding whether or not to perform NSE measurement.