Myelin basic protein in cerebrospinal fluid and other body fluids

Myelin Methods: A Mini-Review

Hematoxylin and eosin (H&E) staining is a suitable approach for detecting substantial structural changes in neural tissues but is less sensitive for identifying subtle alterations to subcellular structures and various chemical constituents, including myelin. Neurohistological methods to better evaluate myelin integrity by light microscopy include acidophilic dyes (eg, eriochrome cyanine R, toluidine blue [used with hard plastic sections]); lipoprotein-binding dyes (eg, Luxol fast blue [LFB], Weil's iron hematoxylin); lipid impregnation with metals (eg, Marchi's, which uses osmium tetroxide for en bloc staining before embedding); and immunohistochemical (IHC) methods to highlight various antigens (eg, myelin basic protein [MBP] and peripheral myelin protein 22 [PMP22]). Some IHC methods reveal enhanced marker expression in damaged myelin (eg, matrix metalloproteinase-9 [MMP9], S100). In neuropathology investigations, H&E is the first-tier screening method, whereas myelin stains (often LFB alone or in combination with dyes that highlight other structural elements) are second-tier procedures performed in combination with other neurohistological procedures to examine neuroaxonal injury and/or glial responses. The choice of myelin method depends on such considerations as cost, institutional preference, the procedure (fixation and embedding medium), and the study objective.

Comparative Sensitivity of MRI Indices for Myelin Assessment in Spinal Cord Regions

Background/Objectives: Although multiple magnetic resonance imaging (MRI) indices are known to be sensitive to the noninvasive assessment of myelin integrity, their relative sensitivities have not been directly compared. This study aimed to identify the most sensitive MRI index for characterizing myelin composition in the spinal cord's gray matter (GM) and white matter (WM). Methods: MRI was performed on a deer's ex vivo cervical spinal cord. Quantitative indices known to be sensitive to myelin, including the myelin water fraction (MWF), magnetization transfer ratio (MTR), the signal ratio between T1- and T2-weighted images (T1W/T2W), fractional anisotropy (FA), mean diffusivity (MD), electrical conductivity (σ), and T1, T2, and T1ρ relaxation times were calculated. Their mean values were compared using repeated measures analysis of variance (ANOVA) and post hoc Bonferroni tests or Friedman and post hoc Wilcoxon tests to identify differences across GM and WM columns possessing distinct myelin distributions, as revealed by histological analysis. Relationships among the indices were examined using Spearman's rank-order correlation analysis. Corrected p < 0.05 was considered statistically significant. Results: All indices except σ differed significantly between GM and all WM columns. Two of the three WM columns had significantly different MWF, FA, MD, and T2, whereas one WM column had significantly different MTR, σ, T1, and T1ρ from the others. A significant moderate to very strong correlation was observed among most indices. Conclusions: The sensitivity of MRI indices in distinguishing spinal cord regions varied. A strategic combination of two or more indices may allow the accurate differentiation of spinal cord regions.

Dysregulated C1q and CD47 in the aging monkey brain: association with myelin damage, microglia reactivity, and cognitive decline

Normal aging, though lacking widespread neurodegeneration, is nevertheless characterized by cognitive impairment in learning, memory, and executive function. The aged brain is spared from neuron loss, but white matter is lost and damage to myelin sheaths accumulates. This myelin damage is strongly associated with cognitive impairment. Although the cause of the myelin damage is not known, microglia dysregulation is a likely contributor. Immunologic proteins interact with microglial receptors to modulate microglia-mediated phagocytosis, which mediates myelin damage clearance and turn-over. Two such proteins, "eat me" signal C1q and "don't eat me" signal CD47, act in opposition with microglia. Both C1q and CD47 have been implicated in Multiple Sclerosis, a demyelinating disease, but whether they play a role in age-related myelin pathology is currently unknown. The present study investigates C1q and CD47 in relation to age-related myelin degeneration using multilabel immunofluorescence, RNAscope, and confocal microscopy in the cingulum bundle of male and female rhesus monkeys across the lifespan. Our findings showed significant age-related elevation in C1q localized to myelin basic protein, and this increase is associated with more severe cognitive impairment. In contrast, CD47 localization to myelin decreased in middle age and oligodendrocyte expression of CD47 RNA decreased with age. Lastly, microglia reactivity increased with age in association with the changes in C1q and CD47. Together, these results suggest disruption in the balance of "eat me" and "don't eat me" signals during normal aging, biasing microglia toward increased reactivity and phagocytosis of myelin, resulting in cognitive deficits.

Significance of immunoglobulins synthesis with central nervous system involvement in Neuro-Behçet's disease

OBJECTIVES

Demyelination and immunocyte-infiltrated lesions have been found in neuro-Behçet's disease (NBD) pathology. Lacking satisfying laboratory biomarkers in NBD impedes standard clinical diagnostics. We aim to explore the ancillary indicators for NBD diagnosis unveiling its potential etiology.

METHODS

28 NBD with defined diagnosis, 29 patients with neuropsychiatric lupus erythematosus, 30 central nervous system idiopathic inflammatory demyelination diseases (CNS-IIDD), 30 CNS infections, 30 cerebrovascular diseases, and 30 noninflammatory neurological diseases (NIND) were retrospectively enrolled. Immunoglobulins (Ig) in serum and cerebral spinal fluid (CSF) were detected by immunonephelometry and myelin basic protein (MBP) by quantitative enzyme-linked immunosorbent assay.

RESULTS

IgA index is almost twice enhanced in NBD than NIND with an accuracy of 0.8488 in differential diagnosis, the sensitivity and specificity of which were 75.00 % and 90.00 % when the cutoff was > 0.6814. The accuracy of CSF Ig and quotient of Ig all exceed 0.90 in discerning NBD with damaged and intact blood-brain barrier (BBB). Clustering analyses divided NBD into two different phenotypes: one with BBB damage has lower Ig synthesis, the other with extra-synthesis in parenchymal sites but with intact BBB. MBP index is significantly correlated with kappa (KAP) index and lambda (LAM) index (r = 0.358, 0.575, P < 0.001), hinting the NBD pathogenesis of CNS demyelination in triggering excessive intrathecal Ig productions and humoral responses.

CONCLUSIONS

IgA index acts as a potential diagnostic indicator in differentiating NBD from NIND and CNS-IIDD. Excessive immunoglobulin production induced by CNS inflammation and demyelination might be latent immunopathogenesis of NBD.

Myelin basic protein and index for neuro-Behçet's disease

Neuro-Behçet's disease (NBD) contributes to poor prognosis in BD patients which lacks reliable laboratory biomarkers in assessing intrathecal injury. This study aimed to determine the diagnostic value of myelin basic protein (MBP), an indicator of central nervous system (CNS) myelin damage, in NBD patients and disease controls. Paired samples of cerebrospinal fluid (CSF) and serum MBP were measured using ELISA, while IgG and Alb were routinely examined before the MBP index was developed. CSF and serum MBP in NBD were significantly higher than in NIND, which could distinguish NBD from NIND with a specificity exceeding 90%, moreover, they could also be excellent discriminators for acute NBD and chronic progressive ones . We found positive linkage between MBP index and IgG index. Serial MBP monitoring confirmed serum MBP's sensitive response to disease recurrence and drug effects, whereas MBP index suggests relapse prior to clinical symptoms. MBP has high diagnostic yield for NBD with demyelination and identifies CNS pathogenic processes before imaging or clinical diagnosis.

Biomarkers of demyelination and axonal damage are decreased after autologous hematopoietic stem cell transplantation for multiple sclerosis

BACKGROUND

Autologous hematopoietic stem cell transplantation (aHSCT) has seen increased use for relapsing-remitting multiple sclerosis (RRMS) in recent years. It is considered one of the most effective treatments for RRMS and has been associated with improvement in disability and prolonged remission. This suggests that the tissue-injuring disease process may have been altered by aHSCT. To assess whether this hypothesis is correct, we performed a study of three commonly used cerebrospinal fluid biomarkers of tissue damage.

METHODS

In this single center study, 63 patients treated with aHSCT at Uppsala University Hospital between January 1st 2012 and January 31st 2019 were screened for participation. A control group consisting of volunteers without neurologic disease were included as a reference. Cerebrospinal fluid concentrations of neurofilament light (NFL), myelin basic protein (MBP) and glial acidic fibrillary protein (GFAp) were determined using ELISA and a multiplex proteomics platform from Meso Scale Discovery.

RESULTS

Forty-three patients with a mean age of 31 and a median follow-up time of 3.9 years were included. Their median baseline expanded disability status scale (EDSS) score was 3.5 and the annualized relapse rate in the year preceding aHSCT was 1.6. At baseline the proportion of patients with values above the upper limit of normal was 67% for NFL, 63% for MBP and 16% for GFAp. At 5-year follow-up, the proportion of patients with values above the upper limit of normal was 12% for NFL, 12% for MBP and 25% for GFAp. The mean concentration of NFL decreased from 920 pg/mL at baseline to 270 pg/mL at 5-year follow-up (p < 0.001); MBP decreased from 1500 to 680 pg/mL (p < 0.001); whereas the mean concentration of GFAp was unchanged.

CONCLUSION

In a majority of patients, biomarkers of demyelination and axonal damage reached normal values within five years from treatment with aHSCT.

Catalytic Antibodies in Bipolar Disorder: Serum IgGs Hydrolyze Myelin Basic Protein

The pathogenesis of bipolar affective disorder is associated with immunological imbalances, a general pro-inflammatory status, neuroinflammation, and impaired white matter integrity. Myelin basic protein (MBP) is one of the major proteins in the myelin sheath of brain oligodendrocytes. For the first time, we have shown that IgGs isolated from sera of bipolar patients can effectively hydrolyze human myelin basic protein (MBP), unlike other test proteins. Several stringent criteria were applied to assign the studied activity to serum IgG. The level of MBP-hydrolyzing activity of IgG from patients with bipolar disorder was statistically significantly 1.6-folds higher than that of healthy individuals. This article presents a detailed characterization of the catalytic properties of MBP-hydrolyzing antibodies in bipolar disorder, including the substrate specificity, inhibitory analysis, pH dependence of hydrolysis, and kinetic parameters of IgG-dependent MBP hydrolysis, providing the heterogeneity of polyclonal MBP-hydrolyzing IgGs and their difference from canonical proteases. The ability of serum IgG to hydrolyze MBP in bipolar disorder may become an additional link between the processes of myelin damage and inflammation.

Myelin loss in C9orf72 hexanucleotide expansion carriers

The most frequent genetic cause of frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) is the hexanucleotide repeat expansion in C9orf72. An important neuropathological hallmark associated with this mutation is the accumulation of the phosphorylated form of TAR (trans-activation response element) DNA-binding protein 43 (pTDP-43). Glia plays a crucial role in the neurodegeneration observed in C9orf72-associated disorders. However, less is known about the role of oligodendrocytes (OLs). Here, we applied digital neuropathological methods to compare the expression pattern of glial cells in the frontal cortex (FrCx) of human post-mortem samples from patients with C9-FTLD and C9-FTLD/ALS, sporadic FTLD (sFTLD), and healthy controls (HCs). We also compared MBP levels in CSF from an independent clinical FTD cohort. We observed an increase in GFAP, and Iba1 immunoreactivity in C9 and sFTLD compared to controls in the gray matter (GM) of the FrCx. We observed a decrease in MBP immunoreactivity in the GM and white matter (WM) of the FrCx of C9, compared to HC and sFTLD. There was a negative correlation between MBP and pTDP-43 in C9 in the WM of the FrCx. We observed an increase in CSF MBP concentrations in C9 and sFTLD compared to HC. In conclusion, the C9 expansion is associated with myelin loss in the frontal cortex. This loss of MBP may be a result of oligodendroglial dysfunction due to the expansion or the presence of pTDP-43 in OLs. Understanding these biological processes will help to identify specific pathways associated with the C9orf72 expansion.

Circulating Level of Myelin Basic Protein Predicts Postherpetic Neuralgia: A Prospective Study

OBJECTIVES

Patients with herpes zoster (HZ) would benefit from accurate prediction of whether they are likely to develop postherpetic neuralgia (PHN). We investigated whether a circulating biomarker of neuronal damage could be a predictor of PHN in this nonmatched prospective, nested, case-control study.

MATERIALS AND METHODS

We included patients with HZ who were within 90 days after rash onset. Volunteers without a history of HZ were recruited as controls. We evaluated epidemiologic factors and circulating neuronal damage biomarkers, including cell-free DNA, myelin basic protein (MBP), and soluble protein-100B (S100B). We conducted logistic regression analyses to develop a prediction model of PHN.

RESULTS

We found that cell-free DNA and MBP levels were higher in patients with HZ (n=71) than in controls (n=37). However, only MBP level was higher in patients who developed PHN (n=25), in comparison with those who did not (n=46). MBP level and 3 clinical factors, age, acute pain severity, and response to treatment drugs were identified as independent predictors of PHN. Receiver operating characteristic (ROC) curve analysis showed that the prediction made using a combination of MBP level and clinical factors had an area under ROC curve of 0.853 (95% confidence interval: 0.764 to 0.943), which was better than prediction using clinical factors alone (area under ROC curve: 0.823, 95% confidence interval: 0.728 to 0.917).

DISCUSSION

Our results indicate that circulating MBP level in patients with HZ is a predictor for PHN. The combination of clinical predictors and MBP level enhanced the prediction performance.

Associations of Serum Cytokine Levels and Interleukin-6-572C/G Polymorphism with Myelin Damage in Chinese Children with Autism Spectrum Disorder

Increasing evidence suggests that immunological disturbances and abnormalities in axonal myelination are involved in the pathophysiology of autism spectrum disorder (ASD). The present study aimed to determine the role of cytokines in myelin damage in Chinese children with ASD and the role of cytokine dysregulation, myelin damage, and cytokine polymorphisms in ASD in Chinese children. The present case-control study included 98 ASD subjects and 252 typically developing (TD) controls; the levels of serum cytokines and myelin basic protein (MBP) were determined using enzyme-linked immunosorbent assay. Cytokine polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism analysis. Autistic clinical manifestations were assessed by the Childhood Autism Rating Scale (CARS). The results showed that serum levels of interleukin (IL)-1β, IL-2R, IL-6, IL-8, and MBP were higher in children with ASD compared with those in TD children. In individuals with ASD, serum MBP level was significantly positively associated with the CARS total score, and serum levels of IL-1β, IL-2R, IL-6, and MBP demonstrated positive correlations. The data identified IL-6*MBP as a factor that influenced the risk of ASD, and IL-2R*MBP was identified as a factor that influenced symptom severity, which influenced auxiliary diagnosis of ASD. The presence of the interleukin-6-572CC genotype was associated with significantly higher serum levels of IL-6 and MBP but did not influence the risk and symptom severity of ASD. Therefore, the results suggested inflammatory responses and myelin damage in Chinese children with ASD. Cytokine dysregulation influenced myelin damage in ASD; moreover, the interactions of the cytokines and myelin damage influenced the risk and symptom severity of ASD. The IL-6-572C/G genotypes may be associated with myelin damage in ASD by influencing the circulating level of IL-6.

CSF levels of myelin basic protein in pediatric patients with ventriculoperitoneal shunt infection

Introduction

Hydrocephalus is a common disorder of the central nervous system (CNS) in the pediatric population. Surgical treatment options involve ventriculoperitoneal shunt (VPS) placement. VPS infection is the most common complication of surgically treated hydrocephalus in pediatric patients [1, 2],which may lead to neuronal damage. Myelin basic protein (MBP) has been proposed as a marker of neuronal injury in a variety of contexts, and MBP levels in the cerebrospinal fluid (CSF) may be used to assess the severity of neuronal damage [1, 3, 4]. Therefore, the aim of this study was to evaluate the CSF level of myelin basic protein (MBP) in a group of pediatric patients with VPS infection.

Material and methods

Thirty CSF samples were collected from pediatric patients with VPS infection. CSF levels of MBP were measured at three time points, marked by contamination detection, obtention of the first sterile CSF culture, and VPS shunt implantation. The collected data were compared with those of the control group composed of children with active congenital hydrocephalus and valid CSF values.

Results

The MBP level in the study group was higher than the corresponding control values in the second and third measurements. The highest MBP level was reached in the study group in the second and third measurements.

Conclusions

The lack of normalization of MBP level in the CSF of children with shunt infection could be connected with ongoing brain damage. It takes longer than the normalization of CSF protein level and pleocytosis. The delay is associated with a prolonged reaction of the immunological system.

Acute Toxic Leukoencephalopathy: Etiologies, Imaging Findings, and Outcomes in 101 Patients

BACKGROUND AND PURPOSE

Prior studies regarding acute toxic leukoencephalopathy (ATL) are either small, or preliminary. Our aim was to evaluate etiologies of and differences in imaging severity and outcomes among various etiologies of ATL.

MATERIALS AND METHODS

MRIs of patients with suspected ATL over 15 years were retrospectively reviewed; inclusion criteria were: MRI <3 weeks of presentation with both DWI and FLAIR. These were jointly graded by two neuroradiologists via a previously described score of severity. Clinical outcome was evaluated via both modified Rankin (mRS) and ATL outcome (ATLOS) scores, each being correlated with the DWI and FLAIR scores. Etiologic subgroups of n > 6 patients were statistically compared.

RESULTS

Of 101 included patients, the 4 subgroups of n > 6 were the following: chemotherapy (n = 35), opiates (n = 19), acute hepatic encephalopathy (n = 14), and immunosuppressants (n = 11). Other causes (n = 22 total) notably included carbon monoxide (n = 3) metronidazole (n = 2), and uremia (n = 1). The mean DWI/FLAIR severity scores were 2.6/2.3, 3.3/3.3, 2.1/2.1 and 2.0/2.5 for chemotherapeutics, opiates, AHE and immunosuppressants, respectively, with significant differences in both imaging severity and outcome (P = .003-.032) among subgroups, particularly immunosuppressant versus chemotherapy-related ATL and immunosuppressants versus opiates (P = .004-.032) related ATL. DWI and FLAIR severity weakly correlated with outcome (ρ = 0.289-.349, P < .005) but correlated stronger in the chemotherapy (ρ = 0.460-.586, P < .010) and opiate (ρ =.472-.608, P < .05) subgroups, which had the worst outcomes. ATL clinically resolved in 36%, with severe outcomes in 23% (coma or death, 9/16 deaths from fludarabine). Notable laboratory results were elevated CSF myelin basic protein levels in 8/9 patients and serum blood urea nitrogen levels in 24/91.

CONCLUSIONS

Clinical outcomes of ATL vary on the basis of etiology, being worse in chemotherapeutic- and opiate-related ATL. Uremia may be a predisposing or exacerbating factor.

Targeted Mass Spectrometry-Based Assays for Relative Quantification of 30 Brain-Related Proteins and Their Clinical Applications

Cerebrospinal fluid (CSF) is a promising clinical sample for identification of novel biomarkers for various neurological disorders. Considering its direct contact with brain tissue, CSF represents a valuable source of brain-related and brain-specific proteins. Multiple sclerosis is an inflammatory, demyelinating neurological disease affecting the central nervous system, and so far there are no diagnostic or prognostic disease specific biomarkers available in the clinic. The primary aim of the present study was to develop a targeted mass spectrometry assay for simultaneous quantification of 30 brain-related proteins in CSF and subsequently to demonstrate assay feasibility in neurological samples derived from multiple sclerosis patients. Our multiplex selected reaction monitoring assay had wide dynamic range (median fold range across peptides = 8.16 × 10³) and high assay reproducibility (median across peptides CV = 4%). Candidate biomarkers were quantified in CSF samples from neurologically healthy individuals (n = 9) and patients diagnosed with clinically isolated syndrome (n = 29) or early multiple sclerosis (n = 15).

Cerebrospinal fluid biomarker and brain biopsy findings in idiopathic normal pressure hydrocephalus

Background

The significance of amyloid precursor protein (APP) and neuroinflammation in idiopathic normal pressure hydrocephalus (iNPH) and Alzheimer's disease (AD) is unknown.

Objective

To investigate the role of soluble APP (sAPP) and amyloid beta (Aβ) isoforms, proinflammatory cytokines, and biomarkers of neuronal damage in the cerebrospinal fluid (CSF) in relation to brain biopsy Aβ and hyperphosphorylated tau (HPτ) findings.

Methods

The study population comprised 102 patients with possible NPH with cortical brain biopsies, ventricular and lumbar CSF samples, and DNA available. The final clinical diagnoses were: 53 iNPH (91% shunt-responders), 26 AD (10 mixed iNPH+AD), and 23 others. Biopsy samples were immunostained against Aβ and HPτ. CSF levels of AD-related biomarkers (Aβ42, p-tau, total tau), non-AD-related Aβ isoforms (Aβ38, Aβ40), sAPP isoforms (sAPPα, sAPPβ), proinflammatory cytokines (several interleukins (IL), interferon-gamma, monocyte chemoattractant protein-1, tumor necrosis factor-alpha) and biomarkers of neuronal damage (neurofilament light and myelin basic protein) were measured. All patients were genotyped for APOE.

Results

Lumbar CSF levels of sAPPα were lower (p<0.05) in patients with shunt-responsive iNPH compared to non-iNPH patients. sAPPβ showed a similar trend (p = 0.06). CSF sAPP isoform levels showed no association to Aβ or HPτ in the brain biopsy. Quantified Aβ load in the brain biopsy showed a negative correlation with CSF levels of Aβ42 in ventricular (r = −0.295, p = 0.003) and lumbar (r = −0.356, p = 0.01) samples, while the levels of Aβ38 and Aβ40 showed no correlation. CSF levels of proinflammatory cytokines and biomarkers of neuronal damage did not associate to the brain biopsy findings, diagnosis, or shunt response. Higher lumbar/ventricular CSF IL-8 ratios (p<0.001) were seen in lumbar samples collected after ventriculostomy compared to the samples collected before the procedure.

Conclusions

The role of sAPP isoforms in iNPH seems to be independent from the amyloid cascade. No neuroinflammatory background was observed in iNPH or AD.

Altered protein networks and cellular pathways in severe west nile disease in mice

Background

The recent West Nile virus (WNV) outbreaks in developed countries, including Europe and the United States, have been associated with significantly higher neuropathology incidence and mortality rate than previously documented. The changing epidemiology, the constant risk of (re-)emergence of more virulent WNV strains, and the lack of effective human antiviral therapy or vaccines makes understanding the pathogenesis of severe disease a priority. Thus, to gain insight into the pathophysiological processes in severe WNV infection, a kinetic analysis of protein expression profiles in the brain of WNV-infected mice was conducted using samples prior to and after the onset of clinical symptoms.

Methodology/Principal Findings

To this end, 2D-DIGE and gel-free iTRAQ labeling approaches were combined, followed by protein identification by mass spectrometry. Using these quantitative proteomic approaches, a set of 148 proteins with modified abundance was identified. The bioinformatics analysis (Ingenuity Pathway Analysis) of each protein dataset originating from the different time-point comparisons revealed that four major functions were altered during the course of WNV-infection in mouse brain tissue: i) modification of cytoskeleton maintenance associated with virus circulation; ii) deregulation of the protein ubiquitination pathway; iii) modulation of the inflammatory response; and iv) alteration of neurological development and neuronal cell death. The differential regulation of selected host protein candidates as being representative of these biological processes were validated by western blotting using an original fluorescence-based method.

Conclusion/Significance

This study provides novel insights into the in vivo kinetic host reactions against WNV infection and the pathophysiologic processes involved, according to clinical symptoms. This work offers useful clues for anti-viral research and further evaluation of early biomarkers for the diagnosis and prevention of severe neurological disease caused by WNV.

Glatiramer acetate in treatment of multiple sclerosis: a toolbox of random co-polymers for targeting inflammatory mechanisms of both the innate and adaptive immune system?

Multiple sclerosis is a disease of the central nervous system, resulting in the demyelination of neurons, causing mild to severe symptoms. Several anti-inflammatory treatments now play a significant role in ameliorating the disease. Glatiramer acetate (GA) is a formulation of random polypeptide copolymers for the treatment of relapsing-remitting MS by limiting the frequency of attacks. While evidence suggests the influence of GA on inflammatory responses, the targeted molecular mechanisms remain poorly understood. Here, we review the multiple pharmacological modes-of-actions of glatiramer acetate in treatment of multiple sclerosis. We discuss in particular a newly discovered interaction between the leukocyte-expressed integrin α(M)β(2) (also called Mac-1, complement receptor 3, or CD11b/CD18) and perspectives on the GA co-polymers as an influence on the function of the innate immune system.

Soluble thrombomodulin levels in plasma of multiple sclerosis patients and their implication

Thrombomodulin (TM) on the cell-surface of cerebrovascular endothelial cells (CECs) is released into blood upon CEC damage. TM promotes activation of protein C (APC), an anticoagulant, anti-inflammatory, neuroprotective molecule that protects CECs and impedes inflammatory cell migration across the blood-brain barrier (BBB). Multiple sclerosis (MS) is associated with CEC damage and BBB dysfunction. We evaluated soluble TM (sTM) levels as a biomarker of BBB integrity and whether glatiramer acetate (GA) influenced sTM levels in MS patients. sTM levels quantified by 2-site ELISA from sera of healthy controls and systemic lupus erythematosus (SLE) patients (CEC-damage positive control) were compared with levels from patients with relapsing-remitting (RRMS) or secondary-progressive MS (SPMS), stratified as: RRMS/GA/no relapse, RRMS/GA/in relapse, RRMS no GA/no relapse, RRMS/no GA/in relapse; and SPMS/no GA. Additionally, soluble endothelial protein C receptor (sEPCR) levels were assessed in the non-stratified MS group, SLE patients, and controls. sTM levels were highest in RRMS patients taking GA with or without relapse, followed in decreasing order by SLE, RRMS/no GA/in relapse, SPMS, RRMS/no GA/no relapse, healthy controls. sEPCR levels were highest in MS patients, then SLE, then controls. sTM may be a useful biomarker of BBB integrity in RRMS patients. Further evaluation of sEPCR is needed. The finding that the highest sTM levels were in RRMS patients taking GA is interesting and warrants further investigation.

Cerebrospinal fluid myelin basic protein is frequently ordered but has little value: a test utilization study

Diagnosis of multiple sclerosis (MS) is facilitated by analyzing biochemical properties of cerebrospinal fluid (CSF). Oligoclonal bands (OCBs) and immunoglobulin G (IgG) index are well-established markers for evaluating patients suspected of having MS. Myelin basic protein (MBP) is also ordered frequently, but its usefulness remains questionable. OCB, IgG index, and MBP were measured in 16,690 consecutive CSF samples. Samples were divided into 2 groups based on MS status known (n = 71) or unknown (n = 16,118). Medical charts of the MS status known group were reviewed to determine their MS status. OCBs have a stronger association to IgG index results than does MBP. Importantly, MBP does not add a statistically significant increase in diagnostic sensitivity or specificity when used in combination with OCB and/or IgG index. The data indicate that MBP is an unnecessary and overused test.

Immunoadsorption therapy in patients with multiple sclerosis with steroid-refractory optical neuritis

BACKGROUND

In multiple sclerosis relapses refractory to intravenous corticosteroid therapy, plasma exchange is recommended. Immunoadsorption (IA) is regarded as an alternative therapy, but its efficacy and putative mechanism of action still needs to be established.

METHODS

We prospectively treated 11 patients with multiple sclerosis who had optical neuritis and fulfilled the indications for apheresis therapy (Trial registration DE/CA25/00007080-00). In total, five IA treatments were performed using tryptophan-IA. Clinical activity (visual acuity, Expanded Disability Status Scale, Incapacity Status Scale), laboratory values and visual evoked potentials were measured before, during and after IA, with a follow-up of six months. Moreover, proteomic analyses were performed to analyze column-bound proteins as well as corresponding changes in patients' sera.

RESULTS

After the third IA, we detected an improvement of vision in eight of eleven patients, whom we termed responders. Amongst these, the mean visual acuity improved from 0.15 ± 0.12 at baseline to 0.47 ± 0.32 after the third IA (P = 0.0252) up to 0.89 ± 0.15 (P < 0.0001) at day 180 ± 10 after IA. Soluble interleukin-2 receptor decreased in responders (P = 0.03), whereas in non-responders it did not. Proteomic analyses of proteins adsorbed to IA columns revealed that several significant immunological proteins as well as central nervous system protein fragments, including myelin basic protein, had been removed by IA.

CONCLUSIONS

IA was effective in the treatment of corticosteroid-refractory optic neuritis. IA influenced the humoral immune response. Strikingly, however, we found strong evidence that demyelination products and immunological mediators were also cleared from plasma by IA.

Evaluation of cerebrospinal fluid in Cavalier King Charles Spaniel dogs diagnosed with Chiari-like malformation with or without concurrent syringomyelia

Syringomyelia is a common clinical problem in the Cavalier King Charles Spaniel dog population. The underlying pathophysiology of the development and progression of syringes is currently unknown. The primary aim of the current study was to determine whether development of syringomyelia is accompanied by alterations in cerebrospinal fluid composition. Patient records of Cavalier King Charles Spaniels with Chiari-like malformations, with or without concurrent syringomyelia, that had magnetic resonance imaging and cerebrospinal fluid analysis between December 2004 and December 2009, were retrospectively reviewed. Total nucleated cell count per microliter, with differential count, red blood cell count per microliter, and protein concentration (g/l), were reviewed. Data were analyzed with the Mann-Whitney U-test. Spearman rank test was used to test association between cerebrospinal fluid composition and syrinx size, and the Fisher exact test was used to compare the presence of macrophages, reactive lymphocytes, and myelin. A P value of ≤ 0.05 was considered significant for statistical tests. Dogs with syringomyelia had a higher total nucleated cell count (syringomyelia: 4/µl [range, 0-15/µl] vs. without syringomyelia: 2/µl [0-8/µl]; P  =  0.0047), higher protein concentration (syringomyelia: 0.26 g/l [0.07-0.42 g/l] vs. without syringomyelia: 0.2 g/l [0.12-0.39 g/l]; P  =  0.039), and an increased neutrophil percentage (syringomyelia: 0% [0-37%] vs. without syringomyelia: 0% [0-21%]; P  =  0.0203) than those with the Chiari-like malformation alone. There was a positive correlation between total nucleated cell count and syrinx size (r  =  0.51; P  =  0.0068). Development of syringomyelia is accompanied by alterations in cerebrospinal fluid composition. The pathogenesis of syringomyelia has not been fully elucidated; therefore, the exact origin of cerebrospinal fluid changes remains unclear.

Osteopontin concentrations are increased in cerebrospinal fluid during attacks of multiple sclerosis

BACKGROUND

The cytokine osteopontin (OPN) is a potential key player in the immunopathogenesis of multiple sclerosis (MS) and a candidate biomarker for disease activity.

OBJECTIVE

The objective of this study was to examine concentrations of OPN in the cerebrospinal fluid (CSF) across the clinical spectrum of MS.

METHODS

Our research consisted of a cross-sectional study of patients from two randomized, placebo-controlled trials. Concentrations of OPN and other blood and CSF markers were determined using an enzyme-linked immunosorbent assay (ELISA). Samples were obtained from untreated patients with exacerbation of clinically isolated syndrome (CIS) (n = 25) and relapsing-remitting MS (RRMS) (n = 41) of whom 48 participated in clinical trials, randomly allocated to treatment with placebo or methylprednisolone (MP) and undergoing repeated sampling after 3 weeks. Furthermore, we obtained CSF and blood samples from patients with primary progressive MS (PPMS, n = 9), secondary progressive MS (SPMS, n = 28) and other neurological disorders (OND, n = 44), and blood samples from 24 healthy subjects.

RESULTS

OPN concentrations were significantly increased in the CSF of patients with CIS (p = 0.02) and RRMS (p < 0.001) in exacerbation compared to patients with OND, and increased levels of OPN were associated with high values of other biomarkers of inflammation. At 3-week follow-up CSF OPN concentrations had decreased significantly from baseline regardless treatment with placebo or MP. Patients with PPMS had increased OPN levels in the CSF (p = 0.004) and high CSF levels of OPN were associated with high degrees of disability.

CONCLUSIONS

OPN concentration in the CSF is a dynamic indicator of disease activity in RRMS, presumably reflecting ongoing inflammation. Increased CSF OPN concentrations in PPMS may indicate ongoing inflammation even in these patients.

Methylation patterns of cell-free plasma DNA in relapsing-remitting multiple sclerosis

BACKGROUND

There is growing interest for identification of new targets for biomarker development in multiple sclerosis (MS). The goal of this study was to compare the concentration and the methylation patterns of cell-free plasma DNA (cfpDNA) in patients with relapsing-remitting multiple sclerosis (RRMS) and healthy individuals.

METHODS

Three 30-patient cohorts were examined: patients with RRMS, in either remission or exacerbation, and healthy individuals as controls. Concentration of cfpDNA was determined using a standard fluorometric assay. Patterns of methylation in 56 gene promoters were determined by a microarray-based assay (MethDet-56). The data were analyzed to identify statistically relevant differences among the study groups.

RESULTS

The concentration of cfpDNA in patients with RRMS was four to eight-fold higher compared to healthy controls. Significant differences in cfpDNA methylation patterns were detected in all three comparisons: RRMS patients in remission versus healthy controls were recognized with 79.2% sensitivity and 92.9% specificity; RRMS patients in exacerbation versus healthy controls were recognized with 75.9% sensitivity and 91.5% specificity; and RRMS patients in exacerbation versus those in remission were recognized with 70.8% sensitivity and 71.2% specificity.

CONCLUSION

Based on our findings, we conclude that patients with RRMS display unique disease- and state-specific changes of cfpDNA. Our findings are of clinical significance as they could be used in the development of potentially new biomarkers for MS. This is the first report in our knowledge describing such changes of cfpDNA in patients with MS.

Myelin basic protein binds to and inhibits the fibrillar assembly of Abeta42 in vitro

The deposition of amyloid beta-protein (Abeta) fibrils into plaques within the brain parenchyma and along cerebral blood vessels is a hallmark of Alzheimer's disease. Abeta peptides are produced through the successive cleavage of the Abeta precursor protein by beta- and gamma-secretase, producing peptides between 39 and 43 amino acids in length. The most common of these are Abeta40 (the most abundant) and Abeta42. Abeta42 is more fibrillogenic than Abeta40 and has been implicated in early Abeta plaque deposition. Our previous studies determined that myelin basic protein (MBP) was capable of inhibiting fibril formation of a highly fibrillogenic Abeta peptide containing both E22Q (Dutch) and D23N (Iowa) mutations associated with familial forms of cerebral amyloid angiopathy [Hoos, M. D., et al. (2007) J. Biol. Chem. 282, 9952-9961]. In this study, we show through a combination of biochemical and ultrastructural techniques that MBP is also capable of inhibiting the beta-sheet fibrillar assembly of the normal Abeta42 peptide. These findings suggest that MBP may play a role in regulating the deposition of Abeta42 and thereby also may regulate the early formation of amyloid plaques in Alzheimer's disease.

Measurement of myelin basic protein in the cerebrospinal fluid of dogs with degenerative myelopathy

BACKGROUND

Analysis of cerebrospinal fluid (CSF) is part of a routine clinical workup in veterinary patients when neurologic disease is suspected. However, knowledge of particular protein markers of disease in CSF is limited. The concentration of myelin basic protein (MBP) in CSF is used as a biochemical marker in humans to evaluate demyelinating lesions in the central nervous system (CNS).

OBJECTIVE

The purpose of this study was to evaluate an ELISA for determination of MBP concentration in the CSF of German shepherd dogs with degenerative myelopathy (GSDM).

METHODS

Cross-reactivity of the anti-human polyclonal antibody used in a commercial ELISA (Active MBP ELISA, Diagnostic Systems Laboratories Inc, Webster, TX, USA) was tested with canine MBP by immunoblotting. CSF samples were collected from both the cisterna magna and the lumbar cistern of 8 clinically healthy control dogs and 8 German shepherd dogs clinically diagnosed with GSDM. MBP concentrations were measured in all CSF samples using the ELISA.

RESULTS

The mean MBP concentration in CSF from the lumbar cistern of dogs with GSDM (3.13 -/+ 0.46 ng/mL) was significantly higher than that in the cisterna magna (0.70 -/+ 0.06 ng/mL) and from both cisternal (0.47 -/+ 0.07 ng/mL) and lumbar (0.94 -/+ 0.37 ng/mL) samples from control dogs.

CONCLUSION

The MBP ELISA has potential as a supplemental test of CSF to diagnose demyelinating disorders in dogs.

A Tale of Two Citrullines—Structural and Functional Aspects of Myelin Basic Protein Deimination in Health and Disease

Myelin basic protein (MBP) binds to negatively charged lipids on the cytosolic surface of oligodendrocyte membranes and is responsible for adhesion of these surfaces in the multilayered myelin sheath. The pattern of extensive post-translational modifications of MBP is dynamic during normal central nervous system (CNS) development and during myelin degeneration in multiple sclerosis (MS), affecting its interactions with the myelin membranes and with other molecules. In particular, the degree of deimination (or citrullination) of MBP is correlated with the severity of MS, and may represent a primary defect that precedes neurodegeneration due to autoimmune attack. That the degree of MBP deimination is also high in early CNS development indicates that this modification plays major physiological roles in myelin assembly. In this review, we describe the structural and functional consequences of MBP deimination in healthy and diseased myelin.

Inflammation in the central nervous system: the role for dendritic cells

Dendritic cells (DCs) are a subclass of antigen-presenting cells critical in the initiation and regulation of adaptive immunity against pathogens and tumors, as well as in the triggering of autoimmunity. Recent studies have provided important knowledge regarding distribution of DCs in the central nervous system (CNS) and their role in intrathecal immune responses. DCs are present in normal meninges, choroid plexus, and cerebrospinal fluid, but absent from the normal brain parenchyma. Inflammation is accompanied by recruitment and/or development of DCs in the affected brain tissue. DCs present in different compartments of the CNS are likely to play a role in the defence against CNS infections, and also may contribute to relapses/chronicity of CNS inflammation and to break-down of tolerance to CNS autoantigens. CNS DCs can therefore be viewed as a future therapeutic target in chronic inflammatory diseases such as multiple sclerosis.

Cerebrospinal fluid affects phenotype and functions of myeloid dendritic cells

Myeloid (CD11c+) dendritic cells (DC) are present in cerebrospinal fluid (CSF), as well as in the meninges and choroid plexus. Functional studies of these DC are hindered or impossible. To obviate this problem, we investigated the effects of CSF supernatants from patients with non-inflammatory neurological diseases (NIND), multiple sclerosis (MS), bacterial meningitis (BM) and Lyme meningoencephalitis (LM) on immature monocyte-derived DC (moDC) from healthy donors. CSF supernatants caused maturation of moDC (MS > LM > NIND > BM), as reflected by a decrease in CD1a, and an increase in HLA-DR, CD80 and CD86 expression. The maturation effect of MS CSF and LM CSF could be blocked by anti-TNF-alpha MoAb or recombinant human IL-10. moDC cultured with BM CSF either remained immature or turned into CD14+ macrophage-like cells and were relatively inefficient at inducing T cell responses in vitro. In contrast, moDC cultured with LM CSF induced strong Th1 responses. Both BM CSF and LM CSF contained IFN-gamma, a cytokine that augments IL-12 production by moDC and hence should confer an ability to induce a Th1 response. However, BM CSF also contained high levels of IL-10, which could antagonize the effects of IFN-gamma on moDC. moDC cultured with MS CSF induced a higher production of IFN-gamma from T cells compared to moDC cultured with NIND CSF or BM CSF. In summary, soluble factors present in the CSF may influence the phenotype and functions of meningeal, choroid plexus and CSF DC which, in turn, may have an impact on the character of intrathecal T cell responses.

Clinical and laboratory features of primary progressive and secondary progressive MS

OBJECTIVE

To compare the clinical and laboratory features of primary progressive (PP) and secondary progressive (SP) MS, to evaluate the role of CSF and urine myelin basic protein-like material (MBPLM) in differentiating PP from SP MS, and to assess the utility of urine MBPLM as a surrogate marker of disease activity in progressive MS.

BACKGROUND

The current categorization of subtypes of MS is based solely on clinical and temporal characteristics of the disease. Laboratory markers are needed that can differentiate reliably the subtypes of MS and serve as surrogate markers of disease progression.

METHODS

Clinical and paraclinical data of 51 PPMS and 140 SPMS patients were reviewed retrospectively. CSF and urine MBPLM were measured using a double-antibody radioimmunoassay.

RESULTS

PPMS was more likely to present with progressive myelopathy (p < or = 0.001) after the age of 40 years (p = < or = 0.001), and it affected men relatively more often than SPMS (male-to-female ratio, 1:1.7 versus 1:3.2 respectively). Ambulatory assistance was required by PP patients more often and earlier than in those with SPMS. The incidence of abnormal CSF, evoked potential, and cranial MRI studies was similar in the two groups. Spinal cord MRI abnormalities were noted significantly more often in SP disease. There was an insignificant trend of higher CSF MBPLM in SPMS compared with PPMS. Urine MBPLM and MBPLM/creatinine were significantly higher in SPMS than in PPMS. However, the values of urine MBPLM and MBPLM/creatinine at the initial visits of patients with PPMS and SPMS were not significantly different. Urine MBPLM/creatinine was significantly higher in both PPMS and SPMS compared with normal control subjects. No correlation was found between urine MBPLM and disease duration or between urine MBPLM and clinical disability. There was no correlation between urine MBPLM/creatinine and either disease duration or clinical disability.

CONCLUSIONS

These findings provide additional evidence of the differences in PPMS and SPMS, notably in the associated changes in MBPLM in urine, and also suggest a possible role for urine MBPLM in identifying patient cohorts. The high urine MBPLM levels in progressive MS patients indicate a potential role of this marker for assessing responsiveness to therapeutic interventions.

Myelin basic protein-like material in the urine of multiple sclerosis patients: relationships to clinical and neuroimaging changes

Urinary myelin basic protein-like material (MBPLM) represents material which is cross-reactive with a cryptic epitope in peptide 84-89 of human myelin basic protein. While normally present at moderate levels in the adult, these levels rise higher in patients who have secondary progressive multiple sclerosis (MS). The increase in urine MBPLM correlates with the burden of disease detected by T2-weighted cranial magnetic resonance imaging. There is no correlation between urinary MBPLM and acute disease activity in relapsing-remitting MS. The first major need for improving the clinical utility of measurements of MBPLM in urine in MS patients is to delineate its exact chemical features so that assays may be improved and a potential biological role of the MBPLM better understood. The second major task is to apply the group data accumulated and apply them to individual patients. This could prove to be means to individually direct treatment and determine its effectiveness.