Long-term study of brain 1H-MRS study in multiple sclerosis: effect of glatiramer acetate therapy on axonal metabolic function and feasibility of long-Term H-MRS monitoring in multiple sclerosis

Neurometabolic changes in multiple sclerosis: Fingolimod versus beta interferon or glatiramer acetate therapy

BACKGROUND AND PURPOSE

Fingolimod has been shown to be more effective in reducing relapse rate and disability than injectable therapies in clinical trials. An increase in N-acetylaspartate (NAA) as measured by MR spectroscopy is correlated with maintaining axonal metabolic functions. This study compared the neurometabolic and volumetric changes in relapsing-remitting multiple sclerosis (RRMS) patients on fingolimod or injectable therapies with healthy controls (HCs).

METHODS

Ninety-eight RRMS (52 on fingolimod, 46 on injectable therapies (27 on glatiramer acetate and 19 on interferon) were age and sex-matched to 51 HCs. RRMS patients underwent cognitive, fatigue, and mental health assessments, as well as an Expanded disability status scale (EDSS). MRI/S was acquired from the hippocampus, posterior cingulate gyrus (PCG), and prefrontal cortex (PFC). Volumetric and neurometabolic measures were compared across cohorts using a univariate general linear model and correlated with clinical severity and neuropsychological scores.

RESULTS

Clinical parameters, MR-volumetric, and neurometabolic profiles showed no differences between treatment groups (p > .05). Compared to HCs, both RRMS cohorts showed volume changes in white matter (-13%), gray matter (-16%), and cerebral spinal fluid (CSF) (+17-23%), as well as reduced NAA (-17%, p = .001, hippocampus), (-7%, p = .001, PCG), and (-9%, p = .001, PFC). MRI/S metrics in three regions were moderately correlated with cognition and fatigue functions.

CONCLUSION

While both treatment arms showed overall similar volumetric and neurometabolic profiles, longitudinal studies are warranted to clarify neurometabolic changes and associations with treatment efficacy.

In vivo Human MR Spectroscopy Using a Clinical Scanner: Development, Applications, and Future Prospects

MR spectroscopy (MRS) is a unique and useful method for noninvasively evaluating biochemical metabolism in human organs and tissues, but its clinical dissemination has been slow and often limited to specialized institutions or hospitals with experts in MRS technology. The number of 3-T clinical MR scanners is now increasing, representing a major opportunity to promote the use of clinical MRS. In this review, we summarize the theoretical background and basic knowledge required to understand the results obtained with MRS and introduce the general consensus on the clinical utility of proton MRS in routine clinical practice. In addition, we present updates to the consensus guidelines on proton MRS published by the members of a working committee of the Japan Society of Magnetic Resonance in Medicine in 2013. Recent research into multinuclear MRS equipped in clinical MR scanners is explained with an eye toward future development. This article seeks to provide an overview of the current status of clinical MRS and to promote the understanding of when it can be useful. In the coming years, MRS-mediated biochemical evaluation is expected to become available for even routine clinical practice.

Creatine and multiple sclerosis

Multiple sclerosis (MS) is a complex and debilitating neurodegenerative disease, with unknown cause(s), unpredictable prognosis, and rather limited treatment options. MS is often accompanied by various metabolic disturbances, with impaired creatine metabolism may play a role in its pathogenesis and the clinical course of the disease. This review summarizes human trials describing alterations in creatine levels in the nervous system and other tissues during MS, affects how certain medications for MS affect brain creatine concentrations, and discusses a possible demand for exogenous creatine as an adjunct therapeutic agent in the management of MS. Creatine metabolism seems to be dysfunctional in MS, indicating a low metabolic state of the brain and other relevant organs in this unpredictable demyelinating disease. A disease-driven brain creatine deficit could be seen as a distinctive pathological facet of severe MS that might be approached with targeted therapies in aim to restore creatine homeostasis.

Molecular Effects of FDA-Approved Multiple Sclerosis Drugs on Glial Cells and Neurons of the Central Nervous System

Multiple sclerosis (MS) is characterized by peripheral and central inflammatory features, as well as demyelination and neurodegeneration. The available Food and Drug Administration (FDA)-approved drugs for MS have been designed to suppress the peripheral immune system. In addition, however, the effects of these drugs may be partially attributed to their influence on glial cells and neurons of the central nervous system (CNS). We here describe the molecular effects of the traditional and more recent FDA-approved MS drugs Fingolimod, Dimethyl Fumarate, Glatiramer Acetate, Interferon-β, Teriflunomide, Laquinimod, Natalizumab, Alemtuzumab and Ocrelizumab on microglia, astrocytes, neurons and oligodendrocytes. Furthermore, we point to a possible common molecular effect of these drugs, namely a key role for NFκB signaling, causing a switch from pro-inflammatory microglia and astrocytes to anti-inflammatory phenotypes of these CNS cell types that recently emerged as central players in MS pathogenesis. This notion argues for the need to further explore the molecular mechanisms underlying MS drug action.

Potential clinical impact of multiparametric quantitative MR spectroscopy in neurological disorders: A review and analysis

PURPOSE

Unlike conventional MR spectroscopy (MRS), which only measures metabolite concentrations, multiparametric MRS also quantifies their longitudinal (T1 ) and transverse (T2 ) relaxation times, as well as the radiofrequency transmitter inhomogeneity (B1+ ). To test whether knowledge of these additional parameters can improve the clinical utility of brain MRS, we compare the conventional and multiparametric approaches in terms of expected classification accuracy in differentiating controls from patients with neurological disorders.

THEORY AND METHODS

A literature review was conducted to compile metabolic concentrations and relaxation times in a wide range of neuropathologies and regions of interest. Simulations were performed to construct receiver operating characteristic curves and compute the associated areas (area under the curve) to examine the sensitivity and specificity of MRS for detecting each pathology in each region. Classification accuracy was assessed using metabolite concentrations corrected using population-averages for T1 , T2 , and B1+ (conventional MRS); using metabolite concentrations corrected using per-subject values (multiparametric MRS); and using an optimal linear multiparametric estimator comprised of the metabolites' concentrations and relaxation constants (multiparametric MRS). Additional simulations were conducted to find the minimal intra-subject precision needed for each parameter.

RESULTS

Compared with conventional MRS, multiparametric approaches yielded area under the curve improvements for almost all neuropathologies and regions of interest. The median area under the curve increased by 0.14 over the entire dataset, and by 0.24 over the 10 instances with the largest individual increases.

CONCLUSIONS

Multiparametric MRS can substantially improve the clinical utility of MRS in diagnosing and assessing brain pathology, motivating the design and use of novel multiparametric sequences.

Quantifying the Metabolic Signature of Multiple Sclerosis by in vivo Proton Magnetic Resonance Spectroscopy: Current Challenges and Future Outlook in the Translation From Proton Signal to Diagnostic Biomarker

Proton magnetic resonance spectroscopy (¹H-MRS) offers a growing variety of methods for querying potential diagnostic biomarkers of multiple sclerosis in living central nervous system tissue. For the past three decades, ¹H-MRS has enabled the acquisition of a rich dataset suggestive of numerous metabolic alterations in lesions, normal-appearing white matter, gray matter, and spinal cord of individuals with multiple sclerosis, but this body of information is not free of seeming internal contradiction. The use of ¹H-MRS signals as diagnostic biomarkers depends on reproducible and generalizable sensitivity and specificity to disease state that can be confounded by a multitude of influences, including experiment group classification and demographics; acquisition sequence; spectral quality and quantifiability; the contribution of macromolecules and lipids to the spectroscopic baseline; spectral quantification pipeline; voxel tissue and lesion composition; T₁ and T₂ relaxation; B₁ field characteristics; and other features of study design, spectral acquisition and processing, and metabolite quantification about which the experimenter may possess imperfect or incomplete information. The direct comparison of ¹H-MRS data from individuals with and without multiple sclerosis poses a special challenge in this regard, as several lines of evidence suggest that experimental cohorts may differ significantly in some of these parameters. We review the existing findings of in vivo¹H-MRS on central nervous system metabolic abnormalities in multiple sclerosis and its subtypes within the context of study design, spectral acquisition and processing, and metabolite quantification and offer an outlook on technical considerations, including the growing use of machine learning, by future investigations into diagnostic biomarkers of multiple sclerosis measurable by ¹H-MRS.

The Evolving Mechanisms of Action of Glatiramer Acetate

Glatiramer acetate (GA) is a synthetic amino acid copolymer that is approved for treatment of relapsing remitting multiple sclerosis (RRMS) and clinically isolated syndrome (CIS). GA reduces multiple sclerosis (MS) disease activity and has shown comparable efficacy with high-dose interferon-β. The mechanism of action (MOA) of GA has long been an enigma. Originally, it was recognized that GA treatment promoted expansion of GA-reactive T-helper 2 and regulatory T cells, and induced the release of neurotrophic factors. However, GA treatment influences both innate and adaptive immune compartments, and it is now recognized that antigen-presenting cells (APCs) are the initial cellular targets for GA. The anti-inflammatory (M2) APCs induced following treatment with GA are responsible for the induction of anti-inflammatory T cells that contribute to its therapeutic benefit. Here, we review studies that have shaped our current understanding of the MOA of GA.

Enduring Clinical Value of Copaxone® (Glatiramer Acetate) in Multiple Sclerosis after 20 Years of Use

Multiple sclerosis (MS) is a chronic progressive neurodegenerative demyelinating disease affecting the central nervous system. Glatiramer acetate (GA; Copaxone®) was the first disease-modifying treatment (DMT) for MS successfully tested in humans (1977) and was approved by the US Food and Drug Administration in December 1996. Since then, there have been numerous developments in the MS field: advances in neuroimaging allowing more rapid and accurate diagnosis; the availability of a range of DMTs including immunosuppressant monoclonal antibodies and oral agents; a more holistic approach to treatment by multidisciplinary teams; and an improved awareness of the need to consider a patient's preferences and patient-reported outcomes such as quality of life. The use of GA has endured throughout these advances. The purpose of this article is to provide an overview of the important developments in the MS field during the 20 years since GA was approved and to review clinical data for GA in MS, with the aim of understanding the continued and widespread use of GA. Both drug-related (efficacy versus side-effect profile and monitoring requirements) and patient factors (preferences regarding mode of administration and possible pregnancy) will be explored.

Proton MR spectroscopy of lesion evolution in multiple sclerosis: Steady-state metabolism and its relationship to conventional imaging

Although MRI assessment of white matter lesions is essential for the clinical management of multiple sclerosis, the processes leading to the formation of lesions and underlying their subsequent MRI appearance are incompletely understood. We used proton MR spectroscopy to study the evolution of N-acetyl-aspartate (NAA), creatine (Cr), choline (Cho), and myo-inositol (mI) in pre-lesional tissue, persistent and transient new lesions, as well as in chronic lesions, and related the results to quantitative MRI measures of T1-hypointensity and T2-volume. Within 10 patients with relapsing-remitting course, there were 180 regions-of-interest consisting of up to seven semi-annual follow-ups of normal-appearing white matter (NAWM, n = 10), pre-lesional tissue giving rise to acute lesions which resolved (n = 3) or persisted (n = 3), and of moderately (n = 9) and severely hypointense (n = 6) chronic lesions. Compared with NAWM, pre-lesional tissue had higher Cr and Cho, while compared with lesions, pre-lesional tissue had higher NAA. Resolving acute lesions showed similar NAA levels pre- and post-formation, suggesting no long-term axonal damage. In chronic lesions, there was an increase in mI, suggesting accumulating astrogliosis. Lesion volume was a better predictor of axonal health than T1-hypointensity, with lesions larger than 1.5 cm³ uniformly exhibiting very low (<4.5 millimolar) NAA concentrations. A positive correlation between longitudinal changes in Cho and in lesion volume in moderately hypointense lesions implied that lesion size is mediated by chronic inflammation. These and other results are integrated in a discussion on the steady-state metabolism of lesion evolution in multiple sclerosis, viewed in the context of conventional MRI measures. Hum Brain Mapp 38:4047-4063, 2017. © 2017 Wiley Periodicals, Inc.

Dendritic cells as therapeutic targets in neuroinflammation

Multiple sclerosis (MS) is the most common chronic inflammatory demyelinating disorder of the central nervous system characterized by infiltration of immune cells and progressive damage to myelin sheaths and neurons. There is still no cure for the disease, but drug regimens can reduce the frequency of relapses and slightly delay progression. Myeloid cells or antigen-presenting cells (APCs) such as dendritic cells (DC), macrophages, and resident microglia, are key players in both mediating immune responses and inducing immune tolerance. Mounting evidence indicates a contribution of these myeloid cells to the pathogenesis of multiple sclerosis and to the effects of treatment, the understanding of which might provide strategies for more potent novel therapeutic interventions. Here, we review recent insights into the role of APCs, with specific focus on DCs in the modulation of neuroinflammation in MS.

MRI measures of neuroprotection and repair in multiple sclerosis

Magnetic resonance imaging (MRI) has had an enormous impact on multiple sclerosis, enabling early diagnosis and providing surrogate markers for monitoring treatment response in clinical trials. Despite these advantages, conventional MRI is limited by lack of pathological specificity and lack of sensitivity to grey matter lesions and to microscopic damage in normal appearing tissue. Quantitative MRI techniques such as measures of parenchymal volume loss, magnetisation transfer imaging, diffusion tensor imaging, and proton magnetic resonance spectroscopy have enhanced our understanding of the nature and mechanism of tissue injury and repair in multiple sclerosis, and provided more specific correlates of neurological deficits and disability accrual. Some of these techniques may be of potential use in clinical trials as surrogate outcome measures for measuring treatment effects on neurodegenerative injury, which is currently difficult to quantify in clinical trials. In this respect, measures of brain volume, T1 hypointensity and magnetisation transfer ratio, and optical coherence tomography appear to be the most promising in the short term. The evidence for a role of neurodegeneration in the pathogenesis of multiple sclerosis, and particularly in the accumulation of irreversible disability, has become increasingly strong over recent years. This has prompted the search for new treatments that can effectively slow down, halt or even reverse such neurodegenerative processes, and in this way restore nervous system function. For this reason, there has been much interest in the development and validation of surrogate markers of neurodegeneration and neuroprotection for use in clinical trials. Advances in magnetic resonance imaging (MRI) technology have allowed the development and implementation of a number of methods that may be promising in this respect. To assess the utility of these methods and to identify needs for further research, sixty experts in neuropathology, clinical measurement, imaging and statistics participated in a meeting held in Amsterdam in 2008 under the aegis of the National Multiple Sclerosis Society. In the proceedings of the meeting, published in 2009 [1], brain volume changes, T1 hypointensity, magnetisation transfer ratio and optical coherence tomography were deemed the most promising measures for screening the neuroprotective capacity of new agents. Other MRI techniques, such as DTI, (1)H-MRS and functional MRI, although potentially useful, require more observational data to help determine the optimal trial design. This article will review some of the issues that were discussed at this meeting, and present some of the imaging techniques that were considered to be the most promising.

Axonal degeneration in multiple sclerosis: can we predict and prevent permanent disability?

Axonal degeneration is a major determinant of permanent neurological impairment during multiple sclerosis (MS). Due to the variable course of clinical disease and the heterogeneity of MS lesions, the mechanisms governing axonal degeneration may differ between disease stages. While the etiology of MS remains elusive, there now exist potential prognostic biomarkers that can predict the conversion to clinically definite MS. Specialized imaging techniques identifying axonal injury and drop-out are becoming established in clinical practice as a predictive measure of MS progression, such as optical coherence tomography (OCT) or diffusion tensor imaging (DTI). However, these imaging techniques are still being debated as predictive biomarkers since controversy surrounds their lesion-specific association with expanded disability status scale (EDSS). A more promising diagnostic measure of axonal degeneration has been argued for the detection of reduced N-acetyl aspartate (NAA) and Creatine ratios via magnetic resonance spectroscopic (MRS) imaging, but again fail with its specificity for predicting actual axonal degeneration. Greater accuracy of predictive biomarkers is therefore warranted and may include CSF neurofilament light chain (NF-L) and neurofilament heavy chain (NF-H) levels, for progressive MS. Furthermore, defining the molecular mechanisms that occur during the neurodegenerative changes in the various subgroups of MS may in fact prove vital for the future development of efficacious neuroprotective therapies. The clinical translation of a combined Na⁺ and Ca²⁺ channel blocker may lead to the establishment of a bona fide neuroprotective agent for the treatment of progressive MS. However, more specific therapeutic targets to limit axonal damage in MS need investigation and may include such integral axonal proteins such as the collapsin response mediator protein-2 (CRMP-2), a molecule which upon post-translational modification may propagate axonal degeneration in MS. In this review, we discuss the current clinical determinants of axonal damage in MS and consider the cellular and molecular mechanisms that may initiate these neurodegenerative changes. In particular we highlight the therapeutic candidates that may formulate novel therapeutic strategies to limit axonal degeneration and EDSS during progressive MS.

Magnetic resonance monitoring of lesion evolution in multiple sclerosis

Disease activity in multiple sclerosis (MS) is strongly linked to the formation of new lesions, which involves a complex sequence of inflammatory, degenerative, and reparative processes. Conventional magnetic resonance imaging (MRI) techniques, such as T2-weighted and gadolinium-enhanced T1-weighted sequences, are highly sensitive in demonstrating the spatial and temporal dissemination of demyelinating plaques in the brain and spinal cord. Hence, these techniques can provide quantitative assessment of disease activity in patients with MS, and they are commonly used in monitoring treatment efficacy in clinical trials and in individual cases. However, the correlation between conventional MRI measures of disease activity and the clinical manifestations of the disease, particularly irreversible disability, is weak. This has been explained by a process of exhaustion of both structural and functional redundancies that increasingly prevents repair and recovery, and by the fact that these imaging techniques do not suffice to explain the entire spectrum of the disease process and lesion development. Nonconventional MRI techniques, such as magnetization transfer imaging, diffusion-weighted imaging, and proton magnetic resonance spectroscopy, which can selectively measure the more destructive aspects of MS pathology and monitor the reparative mechanisms of this disease, are increasingly being used for serial analysis of new lesion formation and provide a better approximation of the pathological substrate of MS plaques. These nonconventional MRI-based measures better assess the serial changes in newly forming lesions and improve our understanding of the relationship between the damaging and reparative mechanisms that occur in MS.

1H magnetic resonance spectroscopy in multiple sclerosis and related disorders

Proton magnetic resonance spectroscopy ((1)H-MRS) is an unconventional technique that allows noninvasive characterization of metabolic abnormalities in the central nervous system. (1)H-MRS provides important insights into the chemical-pathologic changes that occur in patients with multiple sclerosis (MS). In this review article we present the main brain and spinal cord (1)H-MRS features in MS, their diagnostic value in differentiating pseudotumoral demyelinating lesions from primary brain tumors, and their relationship with clinical variables. Last, some data related to the use of (1)H-MRS in therapeutic trials is presented.

Neuroprotection with glatiramer acetate: evidence from the PreCISe trial

The phase III, multicenter, randomized, placebo-controlled PreCISe trial assessed glatiramer acetate (GA) effects in patients with clinically isolated syndromes (CIS) suggestive of multiple sclerosis (MS). To assess the neuroprotective effect of GA in a subset of patients in the PreCISe trial, we used proton magnetic resonance spectroscopy (MRS) to measure N-acetylaspartate (NAA), a marker of neuronal integrity, in a large central volume of brain. Thirty-four CIS patients randomized to GA 20 mg/day (n = 19) SC or placebo (n = 15) were included. Patients who relapsed (developed clinically definite MS [CDMS]) were removed from the substudy. NAA/creatine (NAA/Cr) ratios were compared between GA-treated and placebo-treated patients. Twenty patients with CIS had not converted to CDMS and were still in the double-blind phase of the trial at 12 months of follow-up. Paired changes in NAA/Cr differed significantly in patients treated with GA (+0.14, n = 11) compared with patients receiving placebo (-0.33, n = 9, p = 0.03) at 12 months, consistent with a neuroprotective effect of GA in vivo. Patients with CIS who received GA showed improvement in brain neuroaxonal integrity, as indicated by increased NAA/Cr, relative to comparable patients treated with placebo, who showed a decline in NAA/Cr consistent with findings from natural history studies.

Neurodegeneration in multiple sclerosis: novel treatment strategies

In recent years it has become clear that the neuronal compartment already plays an important role early in the pathology of multiple sclerosis (MS). Neuronal injury in the course of chronic neuroinflammation is a key factor in determining long-term disability in patients. Viewing MS as both inflammatory and neurodegenerative has major implications for therapy, with CNS protection and repair needed in addition to controlling inflammation. Here, the authors' review recently elucidated molecular insights into inflammatory neuronal/axonal pathology in MS and discuss the resulting options regarding neuroprotective and regenerative treatment strategies.

Serial proton MR spectroscopy of gray and white matter in relapsing-remitting MS

OBJECTIVE

To characterize and follow the diffuse gray and white matter (GM/WM) metabolic abnormalities in early relapsing-remitting multiple sclerosis using proton magnetic resonance spectroscopic imaging ((1)H-MRSI).

METHODS

Eighteen recently diagnosed, mildly disabled patients (mean baseline time from diagnosis 32 months, mean Expanded Disability Status Scale [EDSS] score 1.3), all on immunomodulatory medication, were scanned semiannually for 3 years with T1-weighted and T2-weighted MRI and 3D (1)H-MRSI at 3 T. Ten sex- and age-matched controls were followed annually. Global absolute concentrations of N-acetylaspartate (NAA), choline (Cho), creatine (Cr), and myo-inositol (mI) were obtained for all GM and WM in the 360 cm(3) (1)H-MRSI volume of interest.

RESULTS

Patients' average WM Cr, Cho, and mI concentrations (over all time points), 5.3 ± 0.4, 1.6 ± 0.1, and 5.1 ± 0.7 mM, were 8%, 12%, and 11% higher than controls' (p ≤ 0.01), while their WM NAA, 7.4 ± 0.7 mM, was 6% lower (p = 0.07). There were increases with time of patients' WM Cr: 0.1 mM/year, Cho: 0.02 mM/year, and NAA: 0.1 mM/year (all p < 0.05). None of the patients' metabolic concentrations correlated with their EDSS score, relapse rate, GM/WM/CSF fractions, or lesion volume.

CONCLUSIONS

Diffuse WM glial abnormalities were larger in magnitude than the axonal abnormalities and increased over time independently of conventional clinical or imaging metrics and despite immunomodulatory treatment. In contrast, the axonal abnormalities showed partial recovery, suggesting that patients' lower WM NAA levels represented a dysfunction, which may abate with treatment. Absence of detectable diffuse changes in GM suggests that injury there is minimal, focal, or heterogeneous between cortex and deep GM nuclei.

Classical immunomodulatory therapy in multiple sclerosis: how it acts, how it works

Interferon beta (IFNβ) and glatiramer acetate (GA) were the first immunomodulators approved to the treatment of relapsing-remitting multiple sclerosis (MS) and clinically isolated syndromes. Despite the enlargement of the therapeutic armamentarium, IFNβ and GA remain the most widely drugs and the therapeutic mainstay of MS.

OBJECTIVE

To review the mechanisms of action of IFNβ and GA and main clinical results in MS.

RESULTS

IFNβ modulates T and B-cell activity and has effects on the blood-brain barrier. The well proved mechanism of GA is an immune deviation by inducing expression of anti-inflammatory cytokines. Some authors favor the neuroprotective role of both molecules. Clinical trials showed a 30% reduction on the annualized relapse rate and of T2 lesions on magnetic resonance.

CONCLUSION

Although the precise mechanisms how IFNβ and GA achieve their therapeutics effects remain unclear, these drugs have recognized beneficial effects and possess good safety and tolerability profiles. The large clinical experience in treating MS patients with these drugs along almost two decades deserves to be emphasized, at a time where the appearance of drugs with more selective mechanisms of action, but potentially less safer, pave the way to a better selection of the most appropriate individualized treatment.

Efficacy, safety, and cost-effectiveness of glatiramer acetate in the treatment of relapsing-remitting multiple sclerosis

The current Multiple Sclerosis (MS) therapeutic landscape is rapidly growing. Glatiramer acetate (GA) remains unique given its non-immunosuppressive mechanism of action as well as its superior long-term safety and sustained efficacy data. In this review, we discuss proposed mechanisms of action of GA. Then we review efficacy data for reduction of relapses and slowing disability as well as long term safety data. Finally we discuss possible future directions of this unique polymer in the treatment of MS.

Implementation of an absolute brain 1H-MRS quantification method to assess different tissue alterations in multiple sclerosis

Magnetic resonance spectroscopy has emerged as a sensitive modality to detect early and diffuse alterations in multiple sclerosis. Recently, the hypothesis of neurodegenerative pathogenesis has highlightened the interest for measurement of metabolites concentrations, to gain specificity, in a large brain volume encompassing different tissue alterations. Therefore, we proposed in this paper the implementation of an absolute quantification method based on localized spectroscopy at short (30 ms) and long (135 ms) echo time of a volume including normal appearing white matter, cortical gray matter, and lesions. First, methodological developments were implemented including external calibration, and corrections of phased-array coil sensitivity and cerebrospinal fluid volume contribution. Second, these improvements were validated and optimized using an original methodology based on simulations of brain images with lesions. Finally, metabolic alterations were assessed in 65 patients including 26 relapsing-remitting, 17 primary-progressive (PP), 22 secondary-progressive (SP) patients, and in 23 normal subjects. Results showed increases of choline, creatine, and myo-inositol concentrations in PP and SP patients compared to controls, whereas the concentration of N-acetyl compounds remained constant. The major finding of this study was the identification of Cho concentration and Cho/tNA ratio as putative markers of progressive onset, suggesting interesting perspectives in detection and followup of neurodegenerative processes.

Glatiramer acetate in the treatment of multiple sclerosis: emerging concepts regarding its mechanism of action

Glatiramer acetate is a synthetic, random copolymer widely used as a first-line agent for the treatment of relapsing-remitting multiple sclerosis (MS). While earlier studies primarily attributed its clinical effect to a shift in the cytokine secretion of CD4+ T helper (T(h)) cells, growing evidence in MS and its animal model, experimental autoimmune encephalomyelitis (EAE), suggests that glatiramer acetate treatment is associated with a broader immunomodulatory effect on cells of both the innate and adaptive immune system. To date, glatiramer acetate-mediated modulation of antigen-presenting cells (APC) such as monocytes and dendritic cells, CD4+ T(h) cells, CD8+ T cells, Foxp3+ regulatory T cells and antibody production by plasma cells have been reported; in addition, most recent investigations indicate that glatiramer acetate treatment may also promote regulatory B-cell properties. Experimental evidence suggests that, among these diverse effects, a fostering interplay between anti-inflammatory T-cell populations and regulatory type II APC may be the central axis in glatiramer acetate-mediated immune modulation of CNS autoimmune disease. Besides altering inflammatory processes, glatiramer acetate could exert direct neuroprotective and/or neuroregenerative properties, which could be of relevance for the treatment of MS, but even more so for primarily neurodegenerative disorders, such as Alzheimer's or Parkinson's disease. In this review, we provide a comprehensive and critical overview of established and recent findings aiming to elucidate the complex mechanism of action of glatiramer acetate.

Anterior cingulate and frontal lobe white matter spectroscopy in early childhood of former very LBW premature infants

Neurometabolic sequelae of children born at very LBW (VLBW) are not well characterized in early childhood. Proton magnetic resonance spectroscopy (1H-MRS) and developmental assessments were acquired from children age 18-22 mo (16 VLBW/7 term) and 3-4 y (12 VLBW/8 term) from the anterior cingulate and left frontal periventricular white matter. Metabolites obtained included combined N-acetylaspartylglutamate and N-acetylaspartate (NAA), total choline-containing compounds (Cho), combined glutamate and glutamine (Glx), combined creatine and phosphocreatine (Cr), myoinositol (mI), and the following ratios: NAA/Cr, Cho/Cr, Glx/Cr, mI/Cr, and NAA/Cho. Significant differences were present only in white matter: at 18-22 mo, NAA was decreased in VLBW children (p < 0.04), and at 3-4 y, VLBW children showed lower Cr (p < 0.01), lower NAA/Cho (p < 0.005), higher Glx/Cr (p < 0.02), and higher Cho/Cr (p < 0.005). On developmental testing, VLBW children scored lower on language expression (p < 0.05) and on the A-not-B test of early executive function (p < 0.01) at 18-22 mo and had lower verbal intelligence quotient (IQ) (p < 0.005), performance IQ (p < 0.04), and several measures of early executive function including the bear-dragon test (p < 0.004), gift delay (p < 0.07), and summary categorization score (p < 0.03) at 3-4 y. VLBW children may have neurometabolic and developmental abnormalities that persist at least through early childhood.

Glatiramer acetate for multiple sclerosis

BACKGROUND

This is an updated Cochrane review of the previous version published (Cochrane Database of Systematic Reviews 2004 , Issue 1 . Art. No.: CD004678. DOI: 10.1002/14651858.CD004678)Previous studies have shown that glatiramer acetate (Copaxone (R)), a synthetic amino acid polymer is effective in experimental allergic encephalomyelitis (EAE), and improve the outcome of patients with multiple sclerosis (MS).

OBJECTIVES

To verify the clinical efficacy of glatiramer acetate in the treatment of MS patients with relapsing remitting (RR) and progressive (P) course.

SEARCH STRATEGY

We searched the Cochrane MS Group Trials Register (26 March 2009), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2009), MEDLINE (PubMed) (January 1966 to 26 March 2009), EMBASE (January 1988 to 26 March 2009) and hand searching of symposia reports (1990-2009).

SELECTION CRITERIA

All randomised controlled trials (RCTs) comparing glatiramer acetate and placebo in patients with definite MS, whatever the administration schedule and disease course, were eligible for this review.

DATA COLLECTION AND ANALYSIS

Both patients with RR and P MS were analysed. Study protocols were comparable across trials. No major flaws were found in methodological quality. However, efficacy of blinding should be balanced against side effects, including injection-site reactions.

MAIN RESULTS

Among 409 retrieved references, we identified 16 RCTs; six of them, published between 1987 and 2007, met the selection criteria and were included in this review. Five hundred and forty RR patients and 1049 PMS contributed to the analysis. In RR MS, a decrease in the mean EDSS score (-0.33 and -0.45), was found respectively at 2 years and 35 months without any significant effect on sustained disease progression. The reduction of mean number of relapse was evident at 1 year (-0.35 ) 2 years (-0.51 ) and 35 months (-0.64), but significant studies ' heterogeneity was found. The number of hospitalisations and steroid courses were significantly reduced. No benefit was shown in P MS patients. No major toxicity was found. The most common systemic adverse event was a transient and self-limiting patterned reaction of flushing, chest tightness, sweating, palpitations, anxiety. Local injection-site reactions were observed in up to a half of patients treated with glatiramer acetate, thus making a blind assessment of outcomes questionable.

AUTHORS' CONCLUSIONS

Glatiramer acetate did show a partial efficacy in RR MS in term of relapse -related clinical outcomes, without any significant effect on clinical progression of disease measured as sustained disability. The drug is not effective in progressive MS patients.

A new window in multiple sclerosis pathology: non-conventional quantitative magnetic resonance imaging outcomes

Recent findings suggest that neuronal pathology occurs early in the course of multiple sclerosis and seems to be responsible for accumulation of disability. Nonetheless, the nervous system has an intrinsic potential for repair and compensation in the neuronal component. Disease-modifying drugs such as glatiramer acetate interfere with, and down-regulate, inflammatory pathology and slow neurodegeneration. Moreover, certain regulatory cytokines and neurotrophic factors have the capacity to promote neuronal and axonal repair. Given the importance of neuronal injury in multiple sclerosis and the potential of certain treatments for neuronal repair, it is important to possess adequate and sensitive tools to visualise the pathology in the neuronal compartment. The most promising tools to measure neuronal and axonal damage in multiple sclerosis, as well as neuroprotection and repair, are whole brain volume change for quantification of general brain atrophy, and T1 hypointensity (black holes) and magnetisation transfer ratio for measuring evolution of lesion damage. Other promising techniques, such as diffusion tensor imaging-based fibre tracking and magnetic resonance spectroscopy may allow detailed analyses, but these are still in the experimental stage and are not available for routine clinical practice. Further paraclinical measurements such as optical coherence tomography for the evaluation of the anterior visual pathway may have potential as objective surrogate markers for neurodegeneration in multiple sclerosis.

Benefits of glatiramer acetate in the treatment of relapsing-remitting multiple sclerosis

Relapsing-remitting multiple sclerosis is a chronic, progressive disorder marked by repeated exacerbations that lead to increases in neurological disability. Glatiramer acetate and the IFN-betas are recommended as first-line agents for relapsing-remitting multiple sclerosis owing to their potential to reduce frequency and severity of relapses, decrease development of new brain lesions and delay permanent disability. After three decades of study, the preponderance of the evidence suggests that the efficacy of glatiramer acetate is similar to the IFN-betas and new data collected in more naturalistic settings suggest that it may provide improved quality of life, increased productivity and cost-effectiveness. This article will review this evidence including data from very recent head-to-head clinical trials and pharmacoeconomic analyses of cost-effectiveness.

Proton magnetic resonance spectroscopy in multiple sclerosis

Proton magnetic resonance spectroscopy ((1)H-MRS) provides tissue metabolic information in vivo. This article reviews the role of MRS-determined metabolic alterations in lesions, normal-appearing white matter, gray matter, and spinal cord in advancing our knowledge of pathologic changes in multiple sclerosis (MS). In addition, the role of MRS in objectively evaluating therapeutic efficacy is reviewed. This potential metabolic information makes MRS a unique tool to follow MS disease evolution, understand its pathogenesis, evaluate the disease severity, establish a prognosis, and objectively evaluate the efficacy of therapeutic interventions.

Effects of glatiramer acetate on fatigue and days of absence from work in first-time treated relapsing-remitting multiple sclerosis

OBJECTIVES

Treatment of multiple sclerosis patients with glatiramer acetate has been demonstrated a beneficial effect on disease activity. The objective of this prospective naturalistic study was to evaluate the impact of glatiramer acetate on fatigue and work absenteeism.

METHODS

291 treatment-naïve patients with relapsing remitting multiple sclerosis were included and treated with glatiramer acetate for twelve months. Relapse rates, disability, fatigue symptoms, days of absence from work and adverse events were monitored. Fatigue was measured with the MFIS scale and with a visual analogue scale.

RESULTS

Total MFIS scores decreased by 7.6 +/- 16.4 from 34.6 to 27.0 (p < or = 0.001). Significant reductions were observed on all three subscales of the MFIS. Fatigue symptoms, assessed using a visual analogue scale, decreased by 1.04 +/- 2.88 cm from 4.47 cm to 3.43 cm (p < or = 0.001). The proportion of patients absent from work at least once was reduced by a factor of two from 65.1% to 30.1% (p < or = 0.001). Tolerance to treatment was rated as very good or good in 78.3% of patients. Adverse effects, most frequently local injection site reactions, were reported in 15.1% of patients.

CONCLUSION

Treatment with glatiramer acetate was associated with a significant improvement in fatigue symptoms and a marked reduction in absence from work. Treatment was well-tolerated. Such benefits are of relevance to overall patient well-being.