Active MS Lesions Research Articles

Non-contrast magnetic resonance evaluation of active multiple sclerosis lesions: Emerging role of quantitative synthetic magnetic resonance imaging.

The current study aims to explore the utility of novel synthetic MRI-derived quantitative parameters including myelin-correlated volume (MyC) in identifying active MS lesions without injecting gadolinium contrast. 43 MS patients underwent institutional MS protocol including 3D FLAIR and post-contrast 3D T1VIBE sequence on a 1.5T MR Scanner in addition to synthetic MRI sequence. MS plaques were categorised into enhancing (C) and non-enhancing (N) lesions. They were also sub-categorised based on location into periventricular WM lesions (P), deep WM lesions (D), infratentorial lesions (I) and cortical-juxtacortical (C) lesions. ROIs were placed on Synthetic FLAIR images in MS lesions and quantitative parameters of R1, R2, PD and myelin-correlated volume (MyC) obtained. Sensitivity and specificity for various cut-off values to differentiate enhancing from non-enhancing multiple sclerosis lesions were calculated by performing ROC curve analysis and logistic regression analysis. Contrast enhancing lesions demonstrated significantly higher mean R1, R2 values and lower mean PD values in comparison to non-enhancing lesions (p < 0.05) but with limited specificity. Region-wise analysis revealed high AUC values for mean R1 and R2 at cortical-juxtacortical lesions (p < 0.001) followed by periventricular lesions (p < 0.003) for differentiating enhancing from non-enhancing lesions with no significant contribution from MyC and PD values. Synthetic MRI-derived quantitative parameters of mean R1, R2, MyC and PD hold value in differentiating contrast enhancing and non-enhancing MS lesions without administering gadolinium-based contrast agent. However, the current study did not achieve significant specificity for establishing the same.

Accuracy of Noncontrast T2 SPACE in Active MS Cord Lesion Detection.

The diagnosis of active MS lesions is often based on postgadolinium T1-weighted MR imaging. Recent studies suggest a risk of IV gadolinium to patients, predominantly based on gadolinium deposition in tissue. Noncontrast sequences have shown promise in MS diagnosis, but none differentiate acute from chronic MS lesions. We hypothesized that 3D T2 sampling perfection with application-optimized contrasts by using different flip angle evolution (SPACE) MR imaging can help detect and differentiate active-versus-chronic MS lesions without the need for IV contrast. In this single-center retrospective study, 340 spinal MR imaging cases of MS were collected in a 24-month period. Two senior neuroradiologists blindly and independently reviewed postcontrast T1-weighted sagittal and T2-SPACE sagittal images for the presence of MS lesions, associated cord expansion/atrophy on T2-SPACE, and enhancement on postcontrast T1WI. Discrepancies were resolved by consensus between the readers. Sensitivity, specificity, and accuracy of T2-SPACE compared with postcontrast T1WI were computed, and interobserver agreement was calculated. The sensitivity of lesion detection on T2-SPACE was 85.71%, 95% CI, 63.66%-96.95%; with a specificity of 93.52%, 95% CI, 90.06%-96.05%; and an accuracy of 92.99%, 95% CI, 89.58%-95.56. Additionally, 16/21 (84.2%) acute enhancing cord lesions showed cord expansion on T2-SPACE. The interobserver agreement was 92%. Our study shows that T2-SPACE facilitates noncontrast detection of acute MS lesions with high accuracy compared with postcontrast T1WI and with high interobserver agreement. The lack of gadolinium use provides an advantage, bypassing any potential adverse effects of repetitive contrast administration.

Neurofilament Light Chain Levels in Multiple Sclerosis Correlate With Lesions Containing Foamy Macrophages and With Acute Axonal Damage.

Background and ObjectivesTo investigate whether white matter lesion activity, acute axonal damage, and axonal density in MS associate with CSF neurofilament light chain (NfL) levels.MethodsOf 101 brain donors with MS (n = 92 progressive MS, n = 9 relapsing-remitting MS), ventricular CSF was collected, and NfL levels were measured. White matter lesions were classified as active, mixed, inactive, or remyelinated, and microglia/macrophage morphology in active and mixed lesions was classified as ramified, ameboid, or foamy. In addition, axonal density and acute axonal damage were assessed using Bielschowsky and amyloid precursor protein (APP) (immune)histochemistry.ResultsCSF NfL measurements of donors with recent (<1 year) or clinically silent stroke were excluded. CSF NfL levels correlated negatively with disease duration (p = 6.9e-3, r = 0.31). In donors without atrophy, CSF NfL levels correlated positively with the proportion of active and mixed lesions containing foamy microglia/macrophages (p = 9.85e-10 and p = 1.75e-3, respectively), but not with those containing ramified microglia. CSF NfL correlated negatively with proportions of inactive (p = 5.66e-3) and remyelinated lesions (p = 0.03). In the normal appearing pyramid tract, axonal density negatively correlated with CSF NfL levels (Bielschowsky, p = 0.02, r = −0.31), and the presence of acute axonal damage in lesions was related to higher NfL levels (APP, p = 1.17e-6). The amount of acute axonal damage was higher in active lesions with foamy microglia/macrophages and in the rim of mixed lesions with foamy microglia/macrophages when compared with active lesions containing ramified microglia/macrophages (p = 4.6e-3 and p = 0.02, respectively), the center and border of mixed lesions containing ramified microglia/macrophages (center: p = 4.6e-3, border, p = 4.6e-3, and n.s., p = 4.6e-3, respectively), the center of mixed lesions containing foamy microglia/macrophages (p = 4.6e-3 and p = 0.02, respectively), inactive lesions (p = 4.6e-3 and p = 4.6e-3, respectively), and remyelinated lesions (p = 0.03 and p = 0.04, respectively).DiscussionOur results demonstrated that active and mixed white matter MS lesions with foamy microglia show high acute axonal damage and correlate with elevated CSF NfL levels. Our data support the use of this biomarker to monitor inflammatory demyelinating lesion activity with axonal damage in MS.

Efficacy and safety of temelimab in multiple sclerosis: Results of a randomized phase 2b and extension study

Background: The envelope protein of human endogenous retrovirus W (HERV-W-Env) is expressed by macrophages and microglia, mediating axonal damage in chronic active MS lesions. Objective and Methods: This phase 2, double-blind, 48-week trial in relapsing-remitting MS with 48-week extension phase assessed the efficacy and safety of temelimab; a monoclonal antibody neutralizing HERV-W-Env. The primary endpoint was the reduction of cumulative gadolinium-enhancing T1-lesions in brain magnetic resonance imaging (MRI) scans at week 24. Additional endpoints included numbers of T2 and T1-hypointense lesions, magnetization transfer ratio, and brain atrophy. In total, 270 participants were randomized to receive monthly intravenous temelimab (6, 12, or 18 mg/kg) or placebo for 24 weeks; at week 24 placebo-treated participants were re-randomized to treatment groups. Results: The primary endpoint was not met. At week 48, participants treated with 18 mg/kg temelimab had fewer new T1-hypointense lesions (p = 0.014) and showed consistent, however statistically non-significant, reductions in brain atrophy and magnetization transfer ratio decrease, as compared with the placebo/comparator group. These latter two trends were sustained over 96 weeks. No safety issues emerged. Conclusion: Temelimab failed to show an effect on features of acute inflammation but demonstrated preliminary radiological signs of possible anti-neurodegenerative effects. Current data support the development of temelimab for progressive MS. Trial registration: CHANGE-MS: ClinicalTrials.gov: NCT02782858, EudraCT: 2015-004059-29; ANGEL-MS: ClinicalTrials.gov: NCT03239860, EudraCT: 2016-004935-18

Iron Heterogeneity in Early Active Multiple Sclerosis Lesions.

ObjectiveMultiple sclerosis (MS) is a heterogeneous inflammatory demyelinating disease. Iron distribution is altered in MS patients' brains, suggesting iron liberation within active lesions amplifies demyelination and neurodegeneration. Whether the amount and distribution of iron are similar or different among different MS immunopatterns is currently unknown.MethodsWe used synchrotron X‐ray fluorescence imaging, histology, and immunohistochemistry to compare the iron quantity and distribution between immunopattern II and III early active MS lesions. We analyzed archival autopsy and biopsy tissue from 21 MS patients.ResultsImmunopattern II early active lesions contain 64% more iron (95% confidence interval [CI] = 17–127%, p = 0.004) than immunopattern III lesions, and 30% more iron than the surrounding periplaque white matter (95% CI = 3–64%, p = 0.03). Iron in immunopattern III lesions is 28% lower than in the periplaque white matter (95% CI = −40 to −14%, p < 0.001). When normalizing the iron content of early active lesions to that of surrounding periplaque white matter, the ratio is significantly higher in immunopattern II (p < 0.001). Microfocused X‐ray fluorescence imaging shows that iron in immunopattern II lesions localizes to macrophages, whereas macrophages in immunopattern III lesions contain little iron.InterpretationIron distribution and content are heterogeneous in early active MS lesions. Iron accumulates in macrophages in immunopattern II, but not immunopattern III lesions. This heterogeneity in the two most common MS immunopatterns may be explained by different macrophage polarization, origin, or different demyelination mechanisms, and paves the way for developing new or using existing iron‐sensitive magnetic resonance imaging techniques to differentiate among immunopatterns in the general nonbiopsied MS patient population. ANN NEUROL 2021;89:498–510

Abnormal blood-brain barrier water exchange in chronic multiple sclerosis lesions: A preliminary study

Relapsing-remitting multiple sclerosis (RRMS) is associated with persistent blood-brain barrier (BBB) dysfunction. The impact of this persistent dysfunction in both active and chronic MS lesions has yet to be investigated due to technological challenges associated with invasive assessment of BBB water transportation (e.g. 15O-PET). The purpose of this study was to test if persistent BBB dysfunction in RRMS manifests as lower BBB water exchange in chronic lesions using a recently developed noninvasive MRI paradigm. Patients with relapsing-remitting MS and healthy subjects were recruited for this prospective study. The novel Intrinsic Diffusivity Encoding of Arterial Labeled Spins (IDEALS) MRI method was used to map BBB water extraction fraction (Ew) and water permeability surface area product (PSw), as well as cerebral blood flow (CBF). Regional differences in BBB water exchange were evaluated between MS patients (normal appearing white matter [NAWM] and normal appearing gray matter [NAGM]) and healthy subjects (white matter [WM] and gray matter [GM]) and within MS subjects in non gadolinium-based contrast-agent (GBCA) enhancing chronic lesions, perilesional areas, and NAWM. Significantly lower PSw and Ew were observed in NAWM compared to WM (ΔPSw: −11.9 mL/100 g/min, p < .05; ΔEw: −4.3%, p < .01). Significantly lower Ew was observed in NAGM compared to GM (ΔEw: −12.1%, p < .01). Significantly lower PSw and CBF were observed in non-GBCA contrast enhancing lesions compared to NAWM (ΔPSw = −11.5 mL/100 g/min, p < .05; ΔCBF = −8.1 mL/100 g/min, p < .05). Ew was significantly higher in non-GBCA enhancing chronic MS lesions compared to NAWM (ΔEw = 1.6%, p < .05). The lower BBB water exchange in chronic MS lesions is consistent with previously reported observations and may demonstrate metabolic changes associated with MS.

Oxidative Status in Multiple Sclerosis and Off-Targets of Antioxidants: The Case of Edaravone.

MS is a chronic inflammatory disease of the CNS leading to demyelination and neurodegeneration, with a complex and still to be clarified aetiology. Several data, coming from patients' samples and from animal models, show that Oxidative Status (OS) plays an important role in MS pathogenesis. Overproduction of reactive oxidative species by macrophages/microglia can bring about cellular injury and ensuing cell death by oxidizing cardinal cellular components. Oxidized molecules are present in active MS lesions and are associated with neurodegeneration. We undertook a structured search of bibliographic databases for peer-reviewed research literature focusing on OS in MS. The contents of the selected papers were described in the context of a conceptual framework. A special emphasis was given to the results of our study in the field. The results of our three recent studies were put in the context and discussed taking into account the literature on the topic. Oxidative damage underpinned an imbalance shared by MS and neurodegenerative diseases such as Alzheimer and Parkinson diseases. In people with clinically isolated syndrome (an early phase of MS) oxidative stress proved to contribute to disease pathophysiology and to provide biomarkers that may help predict disease evolution. A drug screening platform based on multiple assays to test the remyelinating potential of library of approved compounds showed two anti-oxidants, edaravone and 5-methyl-7- methoxyisoflavone, as active drugs. Moreover, an analysis of 'structure activity relationship' showed off-targets sites of these compounds that accounted for their remyelinating activity, irrespective of their antioxidant action. Overall, edaravone emerges as a candidate to treat complex disease such as MS, where inflammation, oxidative stress and neurodegeneration contribute to disease progression, together or individually, in different phases and disease types. Furthermore, approaches based on drug repositioning seem to maintain the promise of helping discover novel treatment for complex diseases, where molecular targets are largely unknown.

The P2X7 receptor tracer [11C]SMW139 as an in vivo marker of neuroinflammation in multiple sclerosis: a first-in man study

PurposeThe novel PET tracer [11C]SMW139 binds with high affinity to the P2X7 receptor, which is expressed on pro-inflammatory microglia. The purposes of this first in-man study were to characterise pharmacokinetics of [11C]SMW139 in patients with active relapsing remitting multiple sclerosis (RRMS) and healthy controls (HC) and to evaluate its potential to identify in vivo neuroinflammation in RRMS.MethodsFive RRMS patients and 5 age-matched HC underwent 90-min dynamic [11C]SMW139 PET scans, with online continuous and manual arterial sampling to generate a metabolite-corrected arterial plasma input function. Tissue time activity curves were fitted to single- and two-tissue compartment models, and the model that provided the best fits was determined using the Akaike information criterion.ResultsThe optimal model for describing [11C]SMW139 kinetics in both RRMS and HC was a reversible two-tissue compartment model with blood volume parameter and with the dissociation rate k4 fixed to the whole-brain value. Exploratory group level comparisons demonstrated an increased volume of distribution (VT) and binding potential (BPND) in RRMS compared with HC in normal appearing brain regions. BPND in MS lesions was decreased compared with non-lesional white matter, and a further decrease was observed in gadolinium-enhancing lesions. In contrast, increased VT was observed in enhancing lesions, possibly resulting from disruption of the blood-brain barrier in active MS lesions. In addition, there was a high correlation between parameters obtained from 60- to 90-min datasets, although analyses using 60-min data led to a slight underestimation in regional VT and BPND values.ConclusionsThis first in-man study demonstrated that uptake of [11C]SMW139 can be quantified with PET using BPND as a measure for specific binding in healthy controls and RRMS patients. Additional studies are warranted for further clinical evaluation of this novel neuroinflammation tracer.

Macrophage galactose-type lectin (MGL) is induced on M2 microglia and participates in the resolution phase of autoimmune neuroinflammation

BackgroundMultiple sclerosis (MS) involves a misdirected immune attack against myelin in the brain and spinal cord, leading to profound neuroinflammation and neurodegeneration. While the mechanisms of disease pathogenesis have been widely studied, the suppression mechanisms that lead to the resolution of the autoimmune response are still poorly understood. Here, we investigated the role of the C-type lectin receptor macrophage galactose-type lectin (MGL), usually expressed on tolerogenic antigen-presenting cells (APCs), as a negative regulator of autoimmune-driven neuroinflammation.MethodsWe used in silico, immunohistochemical, immunofluorescence, quantitative real-time polymerase chain reaction (qRT-PCR) and flow cytometry analysis to explore the expression and functionality of MGL in human macrophages and microglia, as well as in MS post-mortem tissue. In vitro, we studied the capacity of MGL to mediate apoptosis of experimental autoimmune encephalomyelitis (EAE)-derived T cells and mouse CD4+ T cells. Finally, we evaluated in vivo and ex vivo the immunomodulatory potential of MGL in EAE.ResultsMGL plays a critical role in the resolution phase of EAE as MGL1-deficient (Clec10a−/−) mice showed a similar day of onset but experienced a higher clinical score to that of WT littermates. We demonstrate that the mouse ortholog MGL1 induces apoptosis of autoreactive T cells and diminishes the expression of pro-inflammatory cytokines and inflammatory autoantibodies. Moreover, we show that MGL1 but not MGL2 induces apoptosis of activated mouse CD4+ T cells in vitro. In human settings, we show that MGL expression is increased in active MS lesions and on alternatively activated microglia and macrophages which, in turn, induces the secretion of the immunoregulatory cytokine IL-10, underscoring the clinical relevance of this lectin.ConclusionsOur results show a new role of MGL-expressing APCs as an anti-inflammatory mechanism in autoimmune neuroinflammation by dampening pathogenic T and B cell responses, uncovering a novel clue for neuroprotective therapeutic strategies with relevance for in MS clinical applications.

TSPO PET with [18F]GE-180 sensitively detects focal neuroinflammation in patients with relapsing–remitting multiple sclerosis

Expression of the translocator protein (TSPO) is upregulated in activated macrophages/microglia and is considered to be a marker of neuroinflammation. We investigated the novel TSPO ligand [18F]GE-180 in patients with relapsing-remitting multiple sclerosis (RRMS) to determine the feasibility of [18F]GE-180 PET imaging in RRMS patients and to assess its ability to detect active inflammatory lesions in comparison with the current gold standard, contrast-enhanced magnetic resonance imaging (MRI). Nineteen RRMS patients were prospectively included in this study. All patients underwent TSPO genotyping and were classified as high-affinity, medium-affinity or low-affinity binders (HAB/MAB/LAB). PET scans were performed after administration of 189 ± 12MBq [18F]GE-180, and 60-90min summation images were used for visual analysis and assessment of standardized uptake values (SUV). The frontal nonaffected cortex served as a pseudoreference region (PRR) for evaluation of SUV ratios (SUVR). PET data were correlated with MRI signal abnormalities, i.e. T2 hyperintensity or contrast enhancement (CE). When available, previous MRI data were used to follow the temporal evolution of individual lesions. Focal lesions were identified as hot spots by visual inspection. Such lesions were detected in 17 of the 19 patients and overall 89 [18F]GE-180-positive lesions were found. TSPO genotyping revealed 11 patients with HAB status, 5 with MAB status and 3 with LAB status. There were no associations between underlying binding status (HAB, MAB and LAB) and the signal intensity in either lesions (SUVR 1.87 ± 0.43, 1.95 ± 0.48 and 1.86 ± 0.80, respectively; p = 0.280) or the PRR (SUV 0.36 ± 0.03, 0.40 ± 0.06 and 0.37 ± 0.03, respectively; p = 0.990). Of the 89 [18F]GE-180-positive lesions, 70 showed CE on MRI, while the remainder presented as T2 lesions without CE. SUVR were significantly higher in lesions with CE than in those without (2.00 ± 0.53 vs. 1.60 ± 0.15; p = 0.001). Notably, of 19 [18F]GE-180-positive lesions without CE, 8 previously showed CE, indicating that [18F]GE-180 imaging may be able to detect lesional activity that is sustained beyond the blood-brain barrier breakdown. [18F]GE-180 PET can detect areas of focal macrophage/microglia activation in patients with RRMS in lesions with and without CE on MRI. Therefore, [18F]GE-180 PET imaging is a sensitive and quantitative approach to the detection of active MS lesions. It may provide information beyond contrast-enhanced MRI and is readily applicable to all patients. [18F]GE-180 PET imaging is therefore a promising new tool for the assessment of focal inflammatory activity in MS.

Combining Quantitative Susceptibility Mapping with Automatic Zero Reference (QSM0) and Myelin Water Fraction Imaging to Quantify Iron-Related Myelin Damage in Chronic Active MS Lesions.

A hyperintense rim on susceptibility in chronic MS lesions is consistent with iron deposition, and the purpose of this study was to quantify iron-related myelin damage within these lesions as compared with those without rim. Forty-six patients had 2 longitudinal quantitative susceptibility mapping with automatic zero reference scans with a mean interval of 28.9 ± 11.4 months. Myelin water fraction mapping by using fast acquisition with spiral trajectory and T2 prep was obtained at the second time point to measure myelin damage. Mixed-effects models were used to assess lesion quantitative susceptibility mapping and myelin water fraction values. Quantitative susceptibility mapping scans were on average 6.8 parts per billion higher in 116 rim-positive lesions compared with 441 rim-negative lesions (P < .001). All rim-positive lesions retained a hyperintense rim over time, with increasing quantitative susceptibility mapping values of both the rim and core regions (P < .001). Quantitative susceptibility mapping scans and myelin water fraction in rim-positive lesions decreased from rim to core, which is consistent with rim iron deposition. Whole lesion myelin water fractions for rim-positive and rim-negative lesions were 0.055 ± 0.07 and 0.066 ± 0.04, respectively. In the mixed-effects model, rim-positive lesions had on average 0.01 lower myelin water fraction compared with rim-negative lesions (P < .001). The volume of the rim at the initial quantitative susceptibility mapping scan was negatively associated with follow-up myelin water fraction (P < .01). Quantitative susceptibility mapping rim-positive lesions maintained a hyperintense rim, increased in susceptibility, and had more myelin damage compared with rim-negative lesions. Our results are consistent with the identification of chronic active MS lesions and may provide a target for therapeutic interventions to reduce myelin damage.

Carriage of 2R allele at VNTR polymorphous site of XRCC5 gene increases risk of multiple sclerosis in an Iranian population

The DNA damage has considerably raised in active MS lesions compared to normal brains, indicating the possible role of DNA repairing genes in MS. In the current study, we sought to highlight the association between genetic polymorphisms of XRCC5 and XRCC6 genes, involved in Double Strand Breaks (DSBs) repair, and MS susceptibility. A total of 235 Iranian individuals; including 113 MS patients and 122 healthy controls were participated in this study. They were genotyped for the XRCC5 VNTR polymorphism by polymerase chain reaction (PCR). The genotype analysis of the XRCC6–61C>G polymorphism was performed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. The genotypic frequency of 2R/2R in the XRCC5 VNTR polymorphism was significantly higher in MS patients than controls (p = 0.048). The frequency of individuals with 2R allele was statistically significant in MS patients compared to controls (p = 0.041). Moreover, the frequency of 2R allele of the XRCC5 VNTR polymorphism was found to be significantly difference between MS patients and healthy groups (p = 0.003). The present study suggests that the presence of 2R allele in XRCC5 VNTR gene polymorphism may be a genetic risk factor for MS susceptibility in Iranian population.

Quantitative Susceptibility Mapping and R2* Measured Changes during White Matter Lesion Development in Multiple Sclerosis: Myelin Breakdown, Myelin Debris Degradation and Removal, and Iron Accumulation.

Quantitative susceptibility mapping and R2* are sensitive to myelin and iron changes in multiple sclerosis lesions. This study was designed to characterize lesion changes on quantitative susceptibility mapping and R2* at various gadolinium-enhancement stages. This study included 64 patients with MS with different enhancing patterns in white matter lesions: nodular, shell-like, nonenhancing < 1 year old, and nonenhancing 1-3 years old. These represent acute, late acute, early chronic, and late chronic lesions, respectively. Susceptibility values measured on quantitative susceptibility mapping and R2* values were compared among the 4 lesion types. Their differences were assessed with a generalized estimating equation, controlling for Expanded Disability Status Scale score, age, and disease duration. We analyzed 203 lesions: 80 were nodular-enhancing, of which 77 (96.2%) were isointense on quantitative susceptibility mapping; 33 were shell-enhancing, of which 30 (90.9%) were hyperintense on quantitative susceptibility mapping; and 49 were nonenhancing lesions < 1 year old and 41 were nonenhancing lesions 1-3 years old, all of which were hyperintense on quantitative susceptibility mapping. Their relative susceptibility/R2* values were 0.5 ± 4.4 parts per billion/-5.6 ± 2.9 Hz, 10.2 ± 5.4 parts per billion/-8.0 ± 2.6 Hz, 20.2 ± 7.8 parts per billion/-3.1 ± 2.3 Hz, and 33.2 ± 8.2 parts per billion/-2.0 ± 2.6 Hz, respectively, and were significantly different (P < .005). Early active MS lesions with nodular enhancement show R2* decrease but no quantitative susceptibility mapping change, reflecting myelin breakdown; late active lesions with peripheral enhancement show R2* decrease and quantitative susceptibility mapping increase in the lesion center, reflecting further degradation and removal of myelin debris; and early or late chronic nonenhancing lesions show both quantitative susceptibility mapping and R2* increase, reflecting iron accumulation.

YKL-40 is a CSF biomarker of intrathecal inflammation in secondary progressive multiple sclerosis

YKL-40 (CHI3L1) is a glycoprotein predominantly produced by reactive astrocytes in chronic active MS lesions, which are common in secondary progressive MS. In this study, YKL-40 was investigated in different stages of MS and in relation to MRI findings. YKL-40 levels in CSF samples from two independent patient cohorts of MS patients were determined with ELISA. CSF YKL-40 was increased in patients with active relapsing–remitting MS and correlated with the number of gadolinium enhancing lesions. Patients with secondary progressive MS had similar high levels of YKL-40, whereas not active relapsing–remitting MS patients had YKL-40 levels comparable to healthy controls.

MicroRNA regulation in experimental autoimmune encephalomyelitis in mice and marmosets resembles regulation in human multiple sclerosis lesions

Here we demonstrate that miRNA regulation in marmoset (Callithrix jacchus) and C57/BL6 mouse EAE lesions largely resembles miRNA regulation in active human MS lesions. Detailed quantitative PCR analyses of the most up- and downregulated miRNAs of active human MS lesions in dissected lesions from marmoset EAE brains and inflamed spinal cords of EAE mice revealed that the conserved and highly regulated miRNAs, miRNA-155, miRNA-142-3p, miRNA-146a, miRNA-146b and miRNA-21, turned out to be similarly upregulated in marmoset and mouse EAE lesions.

Reduced raft‐association of NF155 in active MS‐lesions is accompanied by the disruption of the paranodal junction

Neurofascin155 (NF155) is required for the establishment of the paranodal axo-glial junction, the predominant interaction site between myelin and axon. It has been shown that the distribution of NF155 is altered in demyelinating diseases such as multiple sclerosis (MS). However, little is known about the biochemical mechanisms underlying these changes. We therefore compared NF155 in postmortem tissue of active and chronic inactive MS lesions with white matter from healthy controls. Although NF155 showed a very similar expression in all control white matter samples, a strong individual variation was observed in MS-lesions with NF155-levels reduced in most samples. At the same time an NF155-fragment was increased in MS-lesions, suggesting that NF155 is subject to protein degradation in lesion sites. Interestingly, the association of NF155 to membrane microdomains (rafts) was reduced in all lesions, irrespective of the amount of NF155, indicating that membrane association of NF155 was generally affected. Therefore, myelin fractionation experiments were performed to analyze the fate of paranodal proteins during demyelination. Although NF155 was enriched in heavy myelin from both control white matter and active MS-lesions, association of Caspr1/paranodin with heavy myelin was abolished in MS-lesions, demonstrating that paranodal junctions are disrupted. In conclusion, the data support the hypothesis that efficient raft-association of NF155 is essential for the assembly of the paranodal junction and demonstrate that reduced association of NF155 to lipid rafts is accompanied by the disassembly of the paranodal junction and thus contributes to the demyelination process in MS.

Differential release of beta-chemokines in serum and CSF of patients with relapsing-remitting multiple sclerosis.

beta-chemokines were recently demonstrated in active MS-lesions. We tested whether MCP-1 and RANTES can also be detected in CSF and serum of patients with MS and whether release is associated with inflammatory disease activity. CSF and serum from 34 patients with newly diagnosed relapsing-remitting MS (RR-MS), 17 patients with viral meningitis (VM) and 19 patients with non-inflammatory neurological diseases (NIND) were investigated by ELISA. RR-MS patients underwent lumbar puncture and Gd-enhanced MRI examinations within 2 days. MCP-1 was strong intrathecally released in all patients. Compared to NIND CSF-levels were increased in VM (P<0.001) and were decreased in RR-MS (P<0.05). RANTES was only detected in serum in all patients. Levels were higher in VM and RR-MS compared to NIND (P<0.05). A total of 14/34 RR-MS patients exhibited active Gd-enhancing lesions on MRI. They had lower MCP-1 levels in CSF (P<0.001) and serum (P<0.05) and higher serum levels of RANTES (P<0.05) as compared to patients without active lesions. MCP-1 and RANTES are differentially released during acute attacks of RR-MS, which might reflect different immunregulatory roles of these beta-chemokines in RR-MS.

TNF neutralization in MS

<b><i>Objective:</i></b> A double-blind, placebo-controlled phase II study was conducted in 168 patients, most with relapsing-remitting MS, to evaluate whether lenercept would reduce new lesions on MRI. <b><i>Background:</i></b> Tumor necrosis factor (TNF) has been implicated in MS pathogenesis, has been identified in active MS lesions, is toxic to oligodendrocytes in vitro, and worsens the severity of experimental allergic encephalomyelitis (EAE) in animals. Lenercept, a recombinant TNF receptor p55 immunoglobulin fusion protein (sTNFR-IgG p55), protects against EAE. <b><i>Methods:</i></b> Patients received 10, 50, or 100 mg of lenercept or placebo IV every 4 weeks for up to 48 weeks. MRI scans and clinical evaluations were performed at screening, at baseline, and then every 4 weeks (immediately before dosing) through study week 24. <b><i>Results:</i></b> There were no significant differences between groups on any MRI study measure, but the number of lenercept-treated patients experiencing exacerbations was significantly increased compared with patients receiving placebo (<i>p</i> = 0.007) and their exacerbations occurred earlier (<i>p</i> = 0.006). Neurologic deficits tended to be more severe in the lenercept treatment groups, although this did not affect Expanded Disability Status Scale scores. Anti-lenercept antibodies were present in a substantial number of treated patients; serum lenercept trough concentrations were detectable in only a third. Adverse events that increased in frequency in treated patients included headache, nausea, abdominal pain, and hot flushes. <b><i>Conclusions:</i></b> Lenercept failed to be beneficial, but insight into the role of TNF in MS exacerbations was gained.