Guidelines for uniform reporting of body fluid biomarker studies in neurologic disorders.

Objective: The aim of these guidelines is to make the process of reporting body fluid biomarker studies in neurologic disorders more uniform and transparent, in line with existing standards for reporting research in other biomedical areas. Although biomarkers have been around for decades, there are concerns over the high attrition rate of promising candidate biomarkers at later phases of development.

Methods: BioMS-eu consortium, a collaborative network working toward improving the quality of biomarker research in neurologic disorders, discussed the merits of standardizing the reporting of body fluid biomarker research.

Association of cerebral microbleeds in acute ischemic stroke with high serum levels of vascular endothelial growth factor.

Objective: To determine whether vascular endothelial growth factor (VEGF) levels are associated with the presence of cerebral microbleeds (CMBs) in patients after acute ischemic stroke.

Design: A cross-sectional study that used blood samples obtained within 24 hours of symptom onset from patients who experienced acute stroke to measure VEGF levels by enzyme immunoassay. A validated CMB rating scale was used to analyze acutely acquired magnetic resonance images, with the rater blind to clinical details and VEGF levels.

Value of measuring serum vascular endothelial growth factor levels in diagnosing acute ischemic stroke.

Background And Purpose: It has previously been reported that serum levels of vascular endothelial growth factor are raised after acute ischemic stroke compared to healthy controls. The aim of this prospective study was to ascertain whether serum vascular endothelial growth factor measurements could be used to distinguish between acute ischemic stroke and common stroke mimics in the emergency room.

Methods: Blood samples were taken on arrival to hospital and daily for six-days, in 44 patients with suspected ischemic stroke (29 acute infarcts and 15 stroke mimics), arriving within 24 h of symptom onset.

Molecular dissection of Alzheimer's disease neuropathology by depletion of serum amyloid P component.

New therapeutic approaches in Alzheimer's disease are urgently needed. The normal plasma protein, serum amyloid P component (SAP), is always present in cerebrospinal fluid (CSF) and in the pathognomonic lesions of Alzheimer's disease, cerebrovascular and intracerebral Abeta amyloid plaques and neurofibrillary tangles, as a result of its binding to amyloid fibrils and to paired helical filaments, respectively. SAP itself may also be directly neurocytotoxic.

Increase of uric acid and purine compounds in biological fluids of multiple sclerosis patients.

Objectives: In this study, the concentrations of uric acid, purine profile and creatinine in samples of cerebrospinal fluid and serum of multiple sclerosis (MS) patients were measured by HPLC and compared with corresponding values recorded in patients without MS (cerebrospinal fluid) and healthy subjects (serum).

Design And Methods: All samples were deproteinized with ultrafiltration (which ensures minimal sample manipulation and efficient protein removal) and then assayed for the synchronous HPLC separation of uric acid, hypoxanthine, xanthine, inosine, adenosine, guanosine and creatinine.

Results: The values of all compounds assayed were significantly higher in both biological fluids of MS patients with respect to values measured in controls.

Criteria for a clinically informative serum biomarker in acute ischaemic stroke: a review of S100B.

Background And Purpose: Serum S100B has been widely studied as a biomarker in acute ischaemic stroke. The main objective of this review was to appraise the published literature on S100B and determine its clinical applicability.

Methods: Medline was searched to identify studies on S100B (or S-100B) in acute ischaemic stroke.

Longitudinal one-year study of levels and stoichiometry of neurofilament heavy and light chain concentrations in CSF in patients with multiple system atrophy.

Background: Two cerebrospinal fluid (CSF) biomarkers specific for neurodegeneration have recently emerged - the neurofilament light (NfL, 68 kDa) and heavy (NfH, 190-210 kDa) chains. This study investigated whether the CSF NfH and NfL levels or their stoichiometric relationship changed over time in a neuroprotective treatment trial.

Methods: Serial CSF samples (n=95) from 42 patients with multiple system atrophy (MSA), half randomized to treatment with recombinant human growth hormone (r-hGH) and the other half to placebo, were collected at baseline, 6 and 12 months.

Phosphorylation and compactness of neurofilaments in multiple sclerosis: indicators of axonal pathology.

Aims: Axonal pathology extends to the axonal cytoarchitecture leaving its signature on axoskeletal proteins. This study investigated whether neurofilament (NfH) phosphorylation would relate to the dynamics of axonal pathology in multiple sclerosis (MS).

Methods: NfH phosphoforms (SMI32, SMI34, SMI35) were quantified by ELISA from microdissected samples of control and MS brain and spinal cord.

Discrepancies between qualitative and quantitative analysis of cerebrospinal fluid IgG: densitometric comparison of nephelometry-silver versus immuno-enzymes.

Background: Detection of local synthesis of IgG within the central nervous system is important for the diagnosis of brain inflammatory diseases such as multiple sclerosis. This is typically done by comparing the amounts of IgG in serum and parallel cerebrospinal fluid (CSF). Although there have been well-described problems with qualitative versus quantitative measurements of abnormal IgG, such as in myeloma paraproteins, similar difficulties are also found with CSF IgG.

Marathon related death due to brainstem herniation in rehydration-related hyponatraemia: a case report.

Introduction: Identifying marathon runners at risk of neurological deterioration at the end of the race (within a large cohort complaining of exhaustion, dehydration, nausea, headache, dizziness, etc.) is challenging. Here we report a case of rehydration-related hyponatraemia with ensuing brain herniation.

Imaging cadavers: cold FLAIR and noninvasive brain thermometry using CSF diffusion.

There is increasing interest in imaging cadavers for noninvasive autopsies for research purposes. However, the temperature is well below that of in vivo imaging, and a variety of interesting 'cold brain' effects are observed. At lower temperatures conventional FLAIR sequences no longer produce dark cerebrospinal fluid (CSF); T(1) is reduced from about 4.

Early identification of secondary brain damage in subarachnoid hemorrhage: a role for glial fibrillary acidic protein.

Secondary ischaemic deficit adversely affects outcome in patients with subarachnoid hemorrhage (SAH). Astrocytes are vulnerable to ischemia, releasing glial fibrillary acidic protein (GFAP) when challenged. In this study, we followed nine patients with SAH who underwent extra-ventricular drainage for the management of secondary hydrocephalus.

Spectrophotometry for cerebrospinal fluid pigment analysis.

The use of spectrophotometry for the analysis of the cerebrospinal fluid (CSF) is reviewed. The clinically relevant CSF pigments--oxyhemoglobin and bilirubin--are introduced and discussed with regard to clinical differential diagnosis and potentially confounding variables (the four T's: traumatic tap, timing, total protein, and total bilirubin). The practical laboratory aspects of spectrophotometry and automated techniques are presented in the context of analytical and clinical specificity and sensitivity.

Diagnosis of congenital disorders of glycosylation type-I using protein chip technology.

A method for the diagnosis of the congenital disorders of glycosylation type I (CDG-I) by SELDI-TOF-MS of serum transferrin immunocaptured on protein chip arrays is described. The underglycosylation of glycoproteins in CDG-I produces glycoforms of transferrin with masses lower than that of the normal fully glycosylated transferrin. Immobilisation of antitransferrin antibodies on reactive-surface protein chip arrays (RS100) selectively enriched transferrin by at least 100-fold and allowed the detection of patterns of transferrin glycoforms by SELDI-TOF-MS using approximately 0.

A screening assay to detect antigen-specific antibodies within cerebrospinal fluid.

Identification of the aetiology of central nervous system infections requires the detection of either the organism or a microbe-specific immune response within the brain or cerebrospinal fluid. We describe a screening assay to detect herpes simplex virus, varicella zoster virus, cytomegalovirus, measles and Toxoplasma gondii specific antibodies in cerebrospinal fluid. Antigen-specific immunoblotting of oligoclonal IgG and IgM was used to confirm the presence of antibody.

Measurement of high affinity antibodies on antigen-immunoblots.

We describe a semi-quantitative method for measuring the relative affinity of antigen-specific oligoclonal IgG bands separated by isoelectric focusing followed by blotting onto antigen-coated membrane and incubation with sodium thiocyanate. When the developed blot is digitised in greyscale, densitograms can be made and peak areas calculated using ImageJ freeware. By expressing peak area as a percentage of the total area under the curve we have shown that there is a statistically significant rise in percentage of peak area for a given band which persists with increasing molarities of sodium thiocyanate.

Recommended standard of cerebrospinal fluid analysis in the diagnosis of multiple sclerosis: a consensus statement.

New criteria for the diagnosis of multiple sclerosis (MS) were published as the result of an internationally formed committee. To increase the specificity of diagnosis and to minimize the number of false diagnoses, the committee recommended the use of both clinical and paraclinical criteria, the latter involving information obtained from magnetic resonance imaging, evoked potentials, and cerebrospinal fluid (CSF) analysis. Although rigorous magnetic resonance imaging requirements were provided, the "new criteria paper" fell short in terms of guidelines as to how the CSF analysis should be performed and simply equated the IgG index with isoelectric focusing, without any justification.

Why human color vision cannot reliably detect cerebrospinal fluid xanthochromia.

Background: Visual assessment of cerebrospinal fluid (CSF) for xanthochromia (yellow color) is practiced by the majority of laboratories worldwide as a means of diagnosing intracranical bleeds.

Methods: Colorimetric and spectrophotometric analysis of CSF samples for recognizing the presence of bilirubin either in low concentrations or in the presence of hemolysed blood.

Results: The experiments provide the physiological and colorimetric basis for abandoning visual assessment of CSF for xanthochromia.

Quality assurance for cerebrospinal fluid protein analysis: international consensus by an Internet-based group discussion.

A group of neurologists and clinical neurochemists representing twelve countries worked towards a consensus on laboratory techniques to improve the quality of analysis and interpretation of cerebrospinal fluid (CSF) proteins. Consensus was approached via a virtual Lotus Notes-based TeamRoom. This new approach respecting multicultural differences, common views, and minority opinions, is available in http://www.