Myelin-associated proteins are potential diagnostic markers in patients with primary brain tumour.

INTRODUCTION: Taking into account the possibility of myelin-associated proteins having a role in brain tumour development, the study aimed to evaluate the diagnostic usefulness of myelin-associated proteins (Nogo-A, MAG, OMgp) released into extracellular space in patients with brain tumours. PATIENTS AND METHODS: Protein concentration in primary brain tumour (n = 49) and non-tumoural subjects (n = 24) was measured in cerebrospinal fluid (CSF) and serum by means of ELISA. Immunohistochemistry for IDH1-R132H was done on 5-µm thick formalin-fixed, paraffin-embedded tumour sections with the use of an antibody specific for the mutant IDH1-R132H protein. RESULTS: The receiver operator characteristic curve analysis showed that CSF Nogo-A and serum MAG were useful in differentiating patients with primary brain tumour from non-tumoural individuals. This was also true in the case of the separate analysis of the astrocytic tumour versus non-tumoural groups and the meningeal tumour versus non-tumoural groups. Neither Nogo-A nor MAG or OMgp concentrations were significantly different, in serum or CSF, between IDH1 wild-type astrocytic brain tumour patients compared to IDH1 mutant patients. CONCLUSIONS: Our results indicated the potential usefulness of CSF Nogo-A and serum MAG evaluation as circulating biomarkers of primary brain tumours. Because blood is relatively easy to obtain, future research should be conducted to explicitly indicate the value of serum MAG concentration evaluation as a brain tumour biomarker.Key messagesMyelin-associated proteins may be circulating brain tumour biomarkers.Nogo-A and MAG proteins seem to be the most useful in brain tumour diagnosis.Decreased CSF Nogo-A concentration is an adverse prognostic factor for patients' survival.

Aquaporin-4 and myelin oligodendrocyte glycoprotein antibodies in immune-mediated optic neuritis at long-term follow-up.

OBJECTIVES: To re-evaluate serum samples from our 2007 cohort of patients with single-episode isolated ON (SION), recurrent isolated ON (RION), chronic relapsing inflammatory optic neuropathy (CRION), multiple sclerosis-associated ON (MSON) and neuromyelitis optica (NMO). METHODS: We re-screened 103/114 patients with available serum on live cell-based assays (CBA) for aquaporin-4 (AQP4)-M23-IgG and myelin-oligodendrocyte glycoprotein (MOG)-α1-IgG. Further testing included oligoclonal bands, serum levels of glial fibrillar acidic and neurofilament proteins and S100B. We show the impact of updated serology on these patients. RESULTS: Reanalysis of our original cohort revealed that AQP4-IgG seropositivity increased from 56% to 75% for NMO, 5% to 22% for CRION, 6% to 7% for RION, 0% to 7% for MSON and 5% to 6% for SION. MOG-IgG1 was identified in 25% of RION, 25% of CRION, 10% of SION, 0% of MSON and 0% of NMO. As a result, patients have been reclassified incorporating their autoantibody status. Presenting visual acuity was significantly worse in patients who were AQP4-IgG seropositive (p=0.034), but there was no relationship between antibody seropositivity and either ON relapse rate or visual acuity outcome. CONCLUSIONS: The number of patients with seronegative CRION and RION has decreased due to improved detection of autoantibodies over the past decade. It remains essential that the clinical phenotype guides both antibody testing and clinical management. Careful monitoring of the disease course is key when considering whether to treat with prophylactic immune suppression.

Evidence of altered brain regulatory gene expression in tobacco-exposed fetuses.

AIM: We sought to determine the association between prenatal smoking status and expression of fetal brain regulatory genes. METHODS: At delivery, we collected information from parturient women on prenatal smoking habits and analyzed salivary cotinine levels. We obtained neonatal umbilical cord blood and extracted total RNA. We then employed the quantitative polymerase chain reaction (QPCR) analyses and the comparative CT method to calculate the relative gene expression of selected fetal brain regulatory genes responsible for (1) brain growth (brain-derived neutrotrophic factor, BDNF), (2) myelination (proteolipidic protein 1, PLP1 and myelin basic protein, MBP), and (3) neuronal migration and cell-cell interactions during fetal brain development or RLN. The χ2-test, analysis of variance (ANOVA), and the Grubb test were used to evaluate the relationship between prenatal smoking status and relative gene expression levels. Further analysis using bootstrapping was performed to assess the precision of our estimates. RESULTS: Of the 39 maternal-infant dyads included in this study, 25.6% were non-smokers, 43.6% were passive smokers and 30.8% were active smokers. The results showed down-regulation of the selected fetal brain regulatory genes among active smokers. CONCLUSIONS: These findings represent preliminary evidence in humans that intrauterine tobacco exposure impacts fetal brain programming. Future studies are warranted to examine whether our findings represent potential mechanisms through which adverse childhood/adult-onset cognitive and behavioral outcomes that have been previously linked to intrauterine exposure occur.

Neuroglobin and Nogo-a as biomarkers for the severity and prognosis of traumatic brain injury.

OBJECTIVE: To identify the early changes of serum neuroglobin and Nogo-A concentrations and the relations to traumatic brain injury (TBI) severity and prognosis. METHODS: Serum samples were obtained and analyzed from 34 patients with TBI within the first 96 h after injury. Comparative analysis combined with Glasgow Coma Scale (GCS) scores and the 6-month prognosis of these patients was performed. RESULTS: Significant correlations were found between peak serum neuroglobin and Nogo-A concentrations and a patient's GCS score on admission (p < 0.001). The mean peak serum neuroglobin and Nogo-A concentrations were both significantly higher in patients with an unfavorable outcome at 6 months after injury (p < 0.05). CONCLUSIONS: Serum neuroglobin and Nogo-A levels could be suggested as biomarkers for predicting TBI severity and prognosis.

The Value of Circulating Nogo-B for Evaluating Hepatic Functional Reserve in Patients with Cirrhosis.

OBJECTIVE: To examine Nogo-B in liver tissues and plasma of patients with liver cirrhosis and associate them with various clinical parameters. MATERIALS AND METHODS: Nogo-B protein expression was examined by immunohistochemistry in 24 human fibrotic/cirrhotic liver specimens and 10 healthy controls. We determined plasma Nogo-B levels by enzyme-linked immunosorbent assay in 301 patients with liver cirrhosis and 153 healthy controls, and then analyzed various clinical parameters. RESULTS: Nogo-B was mainly expressed in nonparenchymal cells in the liver and was marked increased in liver with significant fibrosis/cirrhosis compared to controls. Moreover, Metavir F4 showed a higher level of expression than F2. Plasma Nogo-B levels were significantly higher in cirrhotic patients than in healthy controls and were the highest in Child-Pugh class C patients. Plasma Nogo-B levels were positively correlated with Child-Pugh scores. However, there was no relationship between plasma Nogo-B levels and etiology of liver diseases, ALT, AST, platelet counts, and the severity of esophagogastric varices. CONCLUSIONS: Nogo-B is mainly expressed in hepatic nonparenchymal cells and is present in plasma. Abnormally high plasma levels of Nogo-B are associated with hepatic cirrhosis and Child-Pugh score, but not correlated with the grade of liver inflammation or portal hypertension. Plasma Nogo-B may be a novel surrogate marker to reflect liver function reserve.

[Effect of Electroacupuncture stimulation of acupoints of the Pericardium Meridian on serum NGF and Nogo-A contents and cerebral NGF and Nogo-A expression in cerebral ischemia rats].

OBJECTIVE: To observe the effect of Electroacupuncture (EA) stimulation of "Tianquan"(PC 2), "Quze" (PC 3), "Neiguan" (PC 6), "Daling" (PC 7) of the Pericardium Meridian on cerebral angiogenesis in cerebral ischemia (CI) rats, so as to reveal its mechanisms underlying improvement of stroke. METHODS: A total of 50 SD rats were equally randomized into normal control, sham, model, EA-Pericardium-Meridian acupoints (EA-PCM) and EA-Lung-Meridian acupoint (EA-LUM) groups. The CI model was established by occlusion of the middle cerebral artery. EA (2-4 V, 20 Hz) was applied to PC 2, PC 3, PC 6, PC 7 and "Tianfu"(LU 3), "Chize" (LU 5), "Lieque" (LU 7), "Taiyuan" (LU 9) of the Lung Meridian for 30 min, once at time-points of 0 h, 6 h, 24 h, 48 h and 72 h, respectively after modeling. Serum nerve growth factor (NGF) and Nogo protein-A (Nogo-A) contents were assayed by enzyme linked immunosorbent assay (ELISA), and cerebral NGF and Nogo-A immunoactivity levels in the ischemic cerebral tissue were detected by immunohistochemistry. RESULTS: (1) Compared to the normal control group, serum NGF and Nogo-A contents, and cerebral NGF immunoactivity level in the model group were significantly increased (P < 0.01). Following EA interventions, serum and cerebral NGF levels were further significantly up-regulated in the EA-PCM and EA-LUM groups (P < 0.01), while serum Nogo-A contents were down-regulated in the two EA groups (P < 0.01). The effect of EA-PCM was markedly superior to that of EA-LUM in up-regulating serum and cerebral NGF levels and down-regulating serum No- go-A level (P < 0.01). No significant differences were found between the normal control and sham groups in serum and cerebral NGF and Nogo-A levels (P > 0.05) , and among the 5 groups in cerebral Nogo-A levels (P > 0.05). CONCLUSION: EA stimulation of acupoints of both Pericardium Meridian and Lung Meridian can up-regulate serum NGF, cerebral NGF expression and down-regulate serum Nogo-A in CI rats, and the effect of Pericardium Meridian is markedly superior to that of Lung Meridian, suggesting a possible better nerve repair effect of EA-PCM acupoints on ischemic brain.

Clinical implications of increased Nogo-B levels in patients with acute coronary syndromes and stable angina pectoris.

Although the relationship between arteriosclerosis and inflammatory response has been recognized in recent years, little is known regarding the change in plasma Nogo-B in coronary artery disease (CAD). Thus, we investigated the expression levels of Nogo-B in CAD patients and examined this relation with disease stages. We recruited 92 CAD patients including 64 with acute coronary syndromes (ACS) and 28 with stable angina pectoris (SAP) cases and 28 healthy controls. The serum concentrations of Nogo-B were measured by enzyme-linked immunosorbent assay (ELISA). The plasma Nogo-B level was significantly higher in patients with ACS and SAP when compared with the healthy controls (both P < 0.05). Multivariate logistic regression analysis revealed that the level of Nogo-B was associated with CAD (odds ratio 1.006, 95% CI: 1.000-1.013, P < 0.05). In conclusion, an increased plasma Nogo-B level may be associated with CAD.

Regulatory role of vitamin D in T-cell reactivity against myelin peptides in relapsing-remitting multiple sclerosis patients.

BACKGROUND: Low levels of plasma 25-hydroxyvitaminD (25(OH)D) are associated with a higher incidence of multiple sclerosis (MS) due to the immune suppressive properties of vitamin D.The aim of this study was to determine the correlation between plasma 25(OH)D concentrations and clinical and immunological variables in a cohort of multiple sclerosis patients. METHODS: Plasma 25(OH)D concentrations were evaluated in summer and winter in 15 primary progressive MS (PPMS) patients, 40 relapsing- remitting MS (RRMS) patients and 40 controls (HC). Protocol variables included demographic and clinical data, radiological findings and immunological variables (oligoclonal bands, HLADR15 and T-lymphocyte proliferation to a definite mix of 7 myelin peptides). RESULTS: During the winter, plasma concentrations were significantly lower in RRMS patients compared to HC, whereas no differences were found in summer. No relationships were found between plasma 25(OH)D concentrations and clinical or radiological variables. RRMS patients with a positive T-cell proliferation to a mix of myelin peptides (n = 31) had lower 25(OH)D concentrations. CONCLUSIONS: 25(OH)D is an immunomodulatory molecule that might have a regulatory role in T-cell proliferation to myelin peptides in RRMS patients.

Immune system markers of neuroinflammation in patients with clinical diagnose of neuromyelitis optica.

Neuromyelitis optica (NMO) is an inflammatory, demyelinating disease of the central nervous system characterized by the association of a serious myelitis and unilateral or bilateral optic neuritis. The present study aimed to analyze the immunological parameters of NMO patients with diagnosis established based on Wingerchuck et al. (1999) criteria. Production of IgG and IgA antibodies to antigens of MBP, PLP 95-116, MOG 92-106, and the cytokines interleukin-4 (IL-4) and interferon-gamma (INF-gamma) were assessed by Elisa assay. The cohort was formed by 28 NMO patients and a matched healthy control group. NMO patients had significant high levels of IgG to MOG (p<0.0001), PLP (p=0.0002) and MBP (p<0.0001), and solely IgA to MBP (p<0.0001). INF-gamma (p=0.61) levels were similar to healthy controls. Increased production of IL-4 (p=0.0084) indicates an important role for this cytokine in the activation of Th2 regulatory cells and of the IgA producers B lymphocyte indicating activation of humoral immunity.

Immune system markers of neuroinflammation in patients with clinical diagnose of neuromyelitis optica / Marcadores imunológicos em pacientes com diagnóstico de neuromielite óptica

Neuromyelitis optica (NMO) is an inflammatory, demyelinating disease of the central nervous system characterized by the association of a serious myelitis and unilateral or bilateral optic neuritis. The present study aimed to analyze the immunological parameters of NMO patients with diagnosis established based on Wingerchuck et al. (1999) criteria. Production of IgG and IgA antibodies to antigens of MBP, PLP 95-116, MOG 92-106, and the cytokines interleukin-4 (IL-4) and interferon-γ (INF-γ) were assessed by Elisa assay. The cohort was formed by 28 NMO patients and a matched healthy control group. NMO patients had significant high levels of IgG to MOG (p<0.0001), PLP (p=0.0002) and MBP (p<0.0001), and solely IgA to MBP (p<0.0001). INF-γ (p=0.61) levels were similar to healthy controls. Increased production of IL-4 (p=0.0084) indicates an important role for this cytokine in the activation of Th2 regulatory cells and of the IgA producers B lymphocyte indicating activation of humoral immunity.

A neuromielite óptica (NMO) é doença inflamatória do sistema nervoso central, caracterizada por mielite aguda ou subaguda grave e neurite óptica unilateral ou bilateral. Este estudo objetiva analisar parâmetros imunológicos de pacientes com critérios de Wingerchuck et al. (1999) para NMO. O método de ELISA avaliou a produção de IgG e IgA para antígenos da proteína básica da mielina (MBP), o proteolipídeo (PLP) 95-116, a glicoproteina associada ao oligodendrócito (MOG) 92-106 e as citocinas interleucina-4 (IL-4) e interferon-gama (INF-γ). Foram incluνdos 28 pacientes com NMO pareados com controles saudáveis. Pacientes com NMO apresentaram níveis significativamente elevados de imunoglobulinas reativas dos isotipos IgG para MOG (p<0,0001), PLP (p=0,0002) e MBP (p<0,0001) e IgA somente para MBP (p<0,0001). Os níveis de INF-γ (p=0,61) foram semelhantes aos controles. A produção elevada de IL-4 (p=0,0084) indica papel importante na ativação de células regulatórias Th2 e linfócitos B produtores de IgA e da ativação da imunidade humoral.

Low levels of Nogo-B in human carotid atherosclerotic plaques are associated with an atheromatous phenotype, restenosis, and stenosis severity.

OBJECTIVE: Reticulon-4/Nogo (Nogo-B) protects mouse arteries from lumen loss by reducing smooth muscle cell (SMC) migration and intimal thickening. Our goal was to determine plaque and circulating levels of Nogo-B in atherosclerotic and control subjects. Therefore, we studied the relationships between local Nogo-B, plaque characteristics, and clinical data in patients undergoing carotid endarterectomy. METHODS AND RESULTS: Western blot analysis showed that endarterectomy specimens from the femoral (n=19) and carotid arteries (n=145) contained significantly less Nogo-B than nonatherosclerotic mammary arteries (n=8; P<0.003) and aortas (n=15; P=0.03). Immunohistochemistry revealed that in atherosclerotic lesions, Nogo-B was expressed by macrophage/foam cells, SMC rich, and neo-vascularized areas. Atheromatous plaques (>40% fat content) showed a significant reduction in Nogo-B expression (P=0.002). Nogo-B expression levels were significantly lower in patients with more than 90% of carotid stenosis (P=0.04) or restenotic lesions after prior carotid intervention (duplex; P=0.01). In contrast, plasmatic levels of Nogo-B (soluble Nogo-B) did not differ between atherosclerotic subjects (n=68) and risk-factor matched controls (n=63; P=0.5). CONCLUSION: Our findings suggest that local reduction of Nogo-B in atherosclerotic tissue might contribute to plaque formation and/or instability triggering luminal narrowing. In contrast, plasma Nogo-B levels are not associated with clinically manifested atherosclerotic disease.

T-cell reactivity to multiple myelin antigens in multiple sclerosis patients and healthy controls.

Myelin proteins, including myelin basic protein (MBP), proteolipid protein (PLP) and myelin oligodendrocyte glycoprotein (MOG) are candidate autoantigens in MS. It is not clear whether MS patients show a predominant reactivity to one or several myelin antigens. We evaluated the IFN-gamma production induced by MBP and MOG and selected MBP-, MOG- and PLP-peptides in MS patients and healthy controls using the IFN-gamma ELISPOT assay. Most MS patients and healthy controls showed a heterogeneous anti-myelin T-cell reactivity. Interestingly in MS patients a positive correlation was found between the anti-MOG and anti-MBP T-cell responses. No myelin peptide was preferentially recognized among the peptides tested (MBP 84-102, 143-168, MOG 1-22, 34-56, 64-86, 74-96, PLP 41-58, 184-199, 190-209). In addition the frequency of IL2R+ MBP reactive T-cells was significantly increased in blood of MS patients as compared with healthy subjects, indicating that MBP reactive T-cells exist in an in vivo activated state in MS patients. Most of the anti-MBP T-cells were of the Th1-type because reactivity was observed in IFN-gamma but not in IL-4 ELISPOT-assays. Using Th1 (IL-12) and Th2 (IL-4) promoting conditions we observed that the cytokine secretion pattern of anti-MBP T-cells still is susceptible to alteration. Our data further indicate that precursor frequency analysis of myelin reactive T-cells by proliferation-based assays may underestimate the true frequency of myelin specific T-cells significantly.

Chronic immune demyelinating neuropathies.

The classification of immune-mediated demyelinating polyneuropathies has become more complex in recent years. Initial definitions of chronic inflammatory demyelinating polyneuropathy (CIDP) were often broad enough to include almost any acquired polyneuropathy with demyelinating features. However, subdivision of acquired demyelinating polyneuropathies into different categories seems justified because 1) several distinct clinical syndromes have been identified, 2) characteristic and distinctive patterns of serum antibody binding are associated with each specific clinical syndrome and, 3) the syndromes respond differently to immune modulating treatments (Table 1). Larger series and controlled trials will be necessary to determine the therapeutic regimens that optimize the benefit:risk considerations for patients with these syndromes.

Anti-peripheral nerve myelin antibodies and terminal activation products of complement in serum of patients with acute brachial plexus neuropathy.

OBJECTIVE: To determine if complement-fixing antibodies to peripheral nerve myelin (anti-PNM antibodies) and terminal complement activation products were increased in serum of patients with brachial plexus neuropathy compared with normal controls. DESIGN: Case series. SETTING: University medical center. PATIENTS: Three patients (aged 6, 39, and 51 years) with acute brachial plexus neuropathy were studied during the acute and recovery phase of their disease. METHODS: Anti-PNM antibodies were measured in serum samples obtained from three patients and 25 normal controls with the C1 fixation and transfer assay. Soluble terminal complement activation products, SC5b-9, were measured by enzyme-linked immunosorbent assay (ELISA) in serum samples of one patient with brachial plexus neuropathy and of five normal controls. RESULTS: Both serum anti-PNM antibodies and soluble terminal complement activation products were increased in the acute phase of brachial plexus neuropathy compared with normal control values and decreased several months later during clinical recovery. CONCLUSION: Complement dependent, antibody-mediated demyelination may participate in the peripheral nerve damage of brachial plexus neuropathy.

New variant in exon 3 of the proteolipid protein (PLP) gene in a family with Pelizaeus-Merzbacher disease.

A C--greater than G transversion has been found in exon 3 of the PLP gene of affected males and their mother in a single sibship with Pelizaeus-merzbacher disease (PMD). The transversion should not result in an amino acid change in the protein but it does result in the loss of a HaeIII restriction endonuclease cleavage site. It is concordant with the disease in this family. One-hundred-ten unrelated X chromosomes are negative for this mutation. No other sequence defect was found in the PLP exons of the affected males. The cause of disease in this family remains unknown, but the association between this rare mutation and PMD is intriguing. The mutation can serve as a marker for following segregation of the PLP gene.

Reactivity with the peripheral myelin glycoprotein P0 in serum from patients with monoclonal IgM gammopathy and polyneuropathy.

The major glycoprotein P0 from human and bovine peripheral nerves carries the L2/HNK-1 and L3 carbohydrate epitopes and is recognized by serum from patients with IgM gammopathy and polyneuropathy. Only serum from patients with reactivity toward the myelin-associated glycoprotein (MAG) was reactive with P0, while serum that did not react with MAG also did not recognize P0. Furthermore, the neural adhesion molecules L1, N-CAM, and J1 were also recognized by the serum that reacted with MAG, while the L3 carbohydrate-carrying cell adhesion molecule AMOG was not recognized. These observations indicate a restricted specificity in carbohydrate reactivity of IgM paraproteins and implicate yet another and, for the first time, peripheral myelin-specific glycoprotein in the pathogenesis of demyelinating neuropathy.

Monoclonal gammopathy and neuropathy: myelin-associated glycoprotein reactivity and clinical characteristics.

Immunoblot analysis was performed on the serum from 29 patients with polyneuropathy and monoclonal gammopathy. Nine patients had IgM spikes, and six of the nine had reactivity against myelin-associated glycoprotein (MAG) associated with a slowly progressive, predominantly sensory neuropathy. In contrast, 23 patients who lacked anti-MAG reactivity had more severe sensory motor neuropathy. Thus, IgM monoclonal gammopathy with reactivity against MAG may define a distinct clinical entity.

Radioimmunoassay for central nervous system myelin-specific proteolipid protein.

A double-antibody radioimmunoassay (RIA) has been developed with antisera to purified rat brain myelin proteolipid protein (PLP). The addition of Triton X-100 allowed antibody-antigen interaction and immune precipitation in the presence of sodium dodecyl sulfate (SDS). The RIA will accurately measure 8-80 ng of PLP in buffer or human serum. The RIA is highly specific for myelin PLP and does not cross-react with material in tissues (heart, kidney, muscle, testicle, and intestine) other than the central nervous system. The antibodies to rat myelin PLP cross-react with PLP from bovine brain homogenate or myelin. Myelin PLP was found to account for 55 and 52% of total myelin protein from bovine and rat brain, respectively. Furthermore, there is a higher concentration of PLP in white than in gray matter corresponding to the degree of myelination. Unlike myelin basic protein, myelin PLP was undetectable in both bovine and rat peripheral nervous system.