Progressive multiple sclerosis: prospects for disease therapy, repair, and restoration of function

Infiltration by monocytes of the central nervous system and its role in multiple sclerosis: reflections on therapeutic strategies

Mononuclear macrophage infiltration in the central nervous system is a prominent feature of neuroinflammation. Recent studies on the pathogenesis and progression of multiple sclerosis have highlighted the multiple roles of mononuclear macrophages in the neuroinflammatory process. Monocytes play a significant role in neuroinflammation, and managing neuroinflammation by manipulating peripheral monocytes stands out as an effective strategy for the treatment of multiple sclerosis, leading to improved patient outcomes. This review outlines the steps involved in the entry of myeloid monocytes into the central nervous system that are targets for effective intervention: the activation of bone marrow hematopoiesis, migration of monocytes in the blood, and penetration of the blood-brain barrier by monocytes. Finally, we summarize the different monocyte subpopulations and their effects on the central nervous system based on phenotypic differences. As activated microglia resemble monocyte-derived macrophages, it is important to accurately identify the role of monocyte-derived macrophages in disease. Depending on the roles played by monocyte-derived macrophages at different stages of the disease, several of these processes can be interrupted to limit neuroinflammation and improve patient prognosis. Here, we discuss possible strategies to target monocytes in neurological diseases, focusing on three key aspects of monocyte infiltration into the central nervous system, to provide new ideas for the treatment of neurodegenerative diseases.

The Iron Maiden: Oligodendroglial metabolic disfunction in multiple sclerosis and mitochondrial signalling

Multiple sclerosis (MS) is an autoimmune disease, governed by oligodendrocyte (OL) dystrophy and central nervous system (CNS) demyelination manifesting variable neurological impairments. Mitochondrial mechanisms may drive myelin biogenesis maintaining the axo-glial unit according to dynamic requisite demands imposed by the axons they ensheath. The promotion of OL maturation and myelination by actively transporting thyroid hormone (TH) into the CNS and thereby facilitating key transcriptional and metabolic pathways that regulate myelin biogenesis is fundamental to sustain the profound energy demands at each axo-glial interface. Deficits in regulatory functions exerted through TH for these physiological roles to be orchestrated by mature OLs, can occur in genetic and acquired myelin disorders, whereby mitochondrial efficiency and eventual dysfunction can lead to profound oligodendrocytopathy, demyelination and neurodegenerative sequelae. TH-dependent transcriptional and metabolic pathways can be dysregulated during acute and chronic MS lesion activity depriving OLs from critical acetyl-CoA biochemical mechanisms governing myelin lipid biosynthesis and at the same time altering the generation of iron metabolism that may drive ferroptotic mechanisms, leading to advancing neurodegeneration.

The global patient-reported outcomes for multiple sclerosis initiative: bridging the gap between clinical research and care - updates at the 2023 plenary event

Significant advancements have been achieved in delineating the progress of the Global PROMS (PROMS) Initiative. The PROMS Initiative, a collaborative endeavor by the European Charcot Foundation and the Multiple Sclerosis International Federation, strives to amplify the influence of patient input on MS care and establish a cohesive perspective on Patient-Reported Outcomes (PROs) for diverse stakeholders. This initiative has established an expansive, participatory governance framework launching four dedicated working groups that have made substantive contributions to research, clinical management, eHealth, and healthcare system reform. The initiative prioritizes the global integration of patient (For the purposes of the Global PROMS Initiative, the term "patient" refers to the people with the disease (aka People with Multiple Sclerosis - pwMS): any individual with lived experience of the disease. People affected by the disease/Multiple Sclerosis: any individual or group that is affected by the disease: E.g., family members, caregivers will be also engaged as the other stakeholders in the initiative). insights into the management of MS care. It merges subjective PROs with objective clinical metrics, thereby addressing the complex variability of disease presentation and progression. Following the completion of its second phase, the initiative aims to help increasing the uptake of eHealth tools and passive PROs within research and clinical settings, affirming its unwavering dedication to the progressive refinement of MS care. Looking forward, the initiative is poised to continue enhancing global surveys, rethinking to the relevant statistical approaches in clinical trials, and cultivating a unified stance among 'industry', regulatory bodies and health policy making regarding the application of PROs in MS healthcare strategies.

Substantial and comparable suppression of disease activity following early initiation of cladribine tablets, ocrelizumab or alemtuzumab as first pharmacologic treatment for relapsing multiple sclerosis: A real world study

BACKGROUND

We describe the efficacy and safety of recent high efficacy disease DMTs in DMT-naive patients with highly active RMS.

METHODS

This was a retrospective, cross sectional study from the Kuwait national MS registry. Patients with RMS who received alemtuzumab, cladribine tablets or ocrelizumab as their first DMT for RMS, with ≥2 year of follow up were included. The primary endpoint was the change in relapse rate from treatment initiation to 1 year; changes in disability (Expanded Disability Status Scale [EDSS]), radiologic activity, the proportion with no evidence of disease activity-3 (NEDA-3), and the frequency of adverse events were secondary endpoints.

RESULTS

Among 123 RRMS patients, 59 received ocrelizumab, 32 received cladribine tablets and 32 received alemtuzumab. About two-thirds (65%) were women. Substantial and similar (p>0.05) reductions occurred at the end of follow-up in annual relapse rate (by 93.2% for ocrelizumab, 87.5% for cladribine tablets, and 90.6% for alemtuzumab). The proportion with new T2 of gadolinium-enhancing MRI lesions across the three groups was reduced from 85-100% to 7-13%. Rates of confirmed disability progression were low (ocrelizumab 6.9%, cladribine tablets 3.1%, alemtuzumab 0%; p=0.280); disability was reduced in 15%, 22% and 38%, respectively. NEDA-3 was observed in 89.8%, 87.5%, and 84.4, respectively (p=0.784). No new or unexpected safety issues occurred.

CONCLUSION

Ocrelizumab, cladribine tablets and alemtuzumab reduced relapse rates and MRI activity, and prevented disease progression, when are initiated early in DMT-naive RMS patients. These data support the early use of high-efficacy DMTs for people with highly active RMS.

Effects of exercise in people with multiple sclerosis: a systematic review and meta-analysis

Background

A growing body of studies have examined the effect of exercise in people with multiple sclerosis (MS), while findings of available studies were conflicting. This meta-analysis aimed to explore the effects of exercise on balance, walking ability, walking endurance, fatigue, and quality of life in people with MS.

Methods

We searched PubMed, Web of Science, Scopus, and Cochrane databases, through March 1, 2024. Inclusion criteria were: (1) RCTs; (2) included an intervention and control group; (3) had people with MS as study subjects; (4) had balance, walking ability, walking endurance, fatigue, or quality of life as the outcome measures. Exclusion criteria were: (1) non-English publications; (2) animal model publications; (3) review articles; and (4) conference articles. A meta-analysis was conducted to calculate weighted mean difference (WMD) and 95% confidence interval (CI). Cochrane risk assessment tool and Physiotherapy Evidence Database (PEDro) scale were used to evaluate the methodological quality of the included studies.

Results

Forty studies with a total of 56 exercise groups (n = 1,300) and 40 control groups (n = 827) were eligible for meta-analysis. Exercise significantly improved BBS (WMD, 3.77; 95% CI, 3.01 to 4.53, P < 0.00001), TUG (WMD, -1.33; 95% CI, -1.57 to -1.08, P < 0.00001), MSWS-12 (WMD, -2.57; 95% CI, -3.99 to -1.15, P = 0.0004), 6MWT (WMD, 25.56; 95% CI, 16.34 to 34.79, P < 0.00001), fatigue (WMD, -4.34; 95% CI, -5.83 to -2.84, P < 0.00001), and MSQOL-54 in people with MS (WMD, 11.80; 95% CI, 5.70 to 17.90, P = 0.0002) in people with MS. Subgroup analyses showed that aerobic exercise, resistance exercise, and multicomponent training were all effective in improving fatigue in people with MS, with resistance exercise being the most effective intervention type. In addition, a younger age was associated with a larger improvement in fatigue. Furthermore, aerobic exercise and multicomponent training were all effective in improving quality of life in people with MS, with aerobic exercise being the most effective intervention type.

Conclusion

Exercise had beneficial effects in improving balance, walking ability, walking endurance, fatigue, and quality of life in people with MS. Resistance exercise and aerobic exercise are the most effective interventions for improving fatigue and quality of life in people with MS, respectively. The effect of exercise on improving fatigue was associated with the age of the participants, with the younger age of the participants, the greater the improvement in fatigue.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=371056, identifier: CRD42022371056.

Flexibility of brain dynamics is increased and predicts clinical impairment in relapsing-remitting but not in secondary progressive multiple sclerosis

Large-scale brain activity has long been investigated under the erroneous assumption of stationarity. Nowadays, we know that resting-state functional connectivity is characterized by aperiodic, scale-free bursts of activity (i.e. neuronal avalanches) that intermittently recruit different brain regions. These different patterns of activity represent a measure of brain flexibility, whose reduction has been found to predict clinical impairment in multiple neurodegenerative diseases such as Parkinson's disease, amyotrophic lateral sclerosis and Alzheimer's disease. Brain flexibility has been recently found increased in multiple sclerosis, but its relationship with clinical disability remains elusive. Also, potential differences in brain dynamics according to the multiple sclerosis clinical phenotypes remain unexplored so far. We performed a brain dynamics study quantifying brain flexibility utilizing the 'functional repertoire' (i.e. the number of configurations of active brain areas) through source reconstruction of magnetoencephalography signals in a cohort of 25 multiple sclerosis patients (10 relapsing-remitting multiple sclerosis and 15 secondary progressive multiple sclerosis) and 25 healthy controls. Multiple sclerosis patients showed a greater number of unique reconfigurations at fast time scales as compared with healthy controls. This difference was mainly driven by the relapsing-remitting multiple sclerosis phenotype, whereas no significant differences in brain dynamics were found between secondary progressive multiple sclerosis and healthy controls. Brain flexibility also showed a different predictive power on clinical disability according to the multiple sclerosis type. For the first time, we investigated brain dynamics in multiple sclerosis patients through high temporal resolution techniques, unveiling differences in brain flexibility according to the multiple sclerosis phenotype and its relationship with clinical disability.

Interpretable and Intuitive Machine Learning Approaches for Predicting Disability Progression in Relapsing-Remitting Multiple Sclerosis Based on Clinical and Gray Matter Atrophy Indicators

RATIONALE AND OBJECTIVES

To investigate whether clinical and gray matter (GM) atrophy indicators can predict disability in relapsing-remitting multiple sclerosis (RRMS) and to enhance the interpretability and intuitiveness of a predictive machine learning model.

MATERIALS AND METHODS

145 and 50 RRMS patients with structural MRI and at least 1-year follow-up Expanded Disability Status Scale (EDSS) results were retrospectively enrolled and placed in the discovery and external test cohorts, respectively. Six clinical and radiomics feature-based machine learning classifiers were trained and tested to predict disability progression in the discovery cohort and validated in the external test set. Partial dependence plot (PDP) analysis and a Shiny web application were conducted to enhance the interpretability and intuitiveness.

RESULTS

In the discovery cohort, 98 patients had disability stability, and 47 patients were classified as having disability progression. In the external test set, 35 patients were disability stable, and 15 patients had disability progression. Models trained with both clinical and radiomics features (area under the curve (AUC), 0.725-0.950) outperformed those trained with clinical (AUC, 0.600-0.740) or radiomics features only (AUC, 0.615-0.945). Among clinical+ radiomics feature models, the logistic regression (LR) classifier-based model performed best, with an AUC of 0.950. Only the radiomics feature-only models were applied in the external test set due to the data collection problem and showed fair performance, with AUCs ranging from 0.617 to 0.753. PDP analysis showed that female patients and those with lower volume, surface area, and symbol digit modalities test (SDMT) scores; greater mean curvature and age; and no disease modifying therapy (DMT) had increased probabilities of disease progression. Finally, a Shiny web application (https://lauralin1104.shinyapps.io/LRshiny/) was developed to calculate the risk of disability progression.

CONCLUSION

Interpretable and intuitive machine learning approaches based on clinical and GM atrophy indicators can help physicians predict disability progression in RRMS patients for clinical decision-making and patient management.

A metformin add-on clinical study in multiple sclerosis to evaluate brain remyelination and neurodegeneration (MACSiMiSE-BRAIN): study protocol for a multi-center randomized placebo controlled clinical trial

Introduction

Despite advances in immunomodulatory treatments of multiple sclerosis (MS), patients with non-active progressive multiple sclerosis (PMS) continue to face a significant unmet need. Demyelination, smoldering inflammation and neurodegeneration are important drivers of disability progression that are insufficiently targeted by current treatment approaches. Promising preclinical data support repurposing of metformin for treatment of PMS. The objective of this clinical trial is to evaluate whether metformin, as add-on treatment, is superior to placebo in delaying disease progression in patients with non-active PMS.

Methods and analysis

MACSiMiSE-BRAIN is a multi-center two-arm, 1:1 randomized, triple-blind, placebo-controlled clinical trial, conducted at five sites in Belgium. Enrollment of 120 patients with non-active PMS is planned. Each participant will undergo a screening visit with assessment of baseline magnetic resonance imaging (MRI), clinical tests, questionnaires, and a safety laboratory assessment. Following randomization, participants will be assigned to either the treatment (metformin) or placebo group. Subsequently, they will undergo a 96-week follow-up period. The primary outcome is change in walking speed, as measured by the Timed 25-Foot Walk Test, from baseline to 96 weeks. Secondary outcome measures include change in neurological disability (Expanded Disability Status Score), information processing speed (Symbol Digit Modalities Test) and hand function (9-Hole Peg test). Annual brain MRI will be performed to assess evolution in brain volumetry and diffusion metrics. As patients may not progress in all domains, a composite outcome, the Overall Disability Response Score will be additionally evaluated as an exploratory outcome. Other exploratory outcomes will consist of paramagnetic rim lesions, the 2-minute walking test and health economic analyses as well as both patient- and caregiver-reported outcomes like the EQ-5D-5L, the Multiple Sclerosis Impact Scale and the Caregiver Strain Index.

Ethics and dissemination

Clinical trial authorization from regulatory agencies [Ethical Committee and Federal Agency for Medicines and Health Products (FAMHP)] was obtained after submission to the centralized European Clinical Trial Information System. The results of this clinical trial will be disseminated at scientific conferences, in peer-reviewed publications, to patient associations and the general public.

Trial registration

ClinicalTrials.gov Identifier: NCT05893225, EUCT number: 2023-503190-38-00.

Pathophysiology, Diagnosis, Treatment and Emerging Neurotherapeutic Targets for Progressive Multiple Sclerosis: The Age of PIRA

More than one million individuals are impacted by progressive forms of multiple sclerosis. The literature examining the management of MS has focused primarily on relapsing forms of disease, and effective therapies targeting progressive mechanisms in MS remains a significant unmet need. Despite this, there are several encouraging potential therapeutics on the horizon. Improved understanding of mechanisms underlying MS progression, identification and validation of biomarkers, identification of novel therapeutic targets, and improved trial design are needed to further propel progress in the management of individuals with progressive forms of MS.

Ocrelizumab associates with reduced cerebrospinal fluid B and CD20dim CD4+ T cells in primary progressive multiple sclerosis

The anti-CD20 monoclonal antibody ocrelizumab reduces disability progression in primary progressive multiple sclerosis. CD20 is a prototypical B-cell marker; however, subpopulations of CD4+ and CD8+ T cells in peripheral blood and cerebrospinal fluid also express low levels of CD20 (CD20dim). Therefore, direct targeting and depletion of these CD20dim T-cell subpopulations may contribute to the therapeutic effect of ocrelizumab. The aim of this observational cohort study was to compare CD20+ B-cell and CD20dim T-cell distributions between peripheral blood and cerebrospinal fluid of ocrelizumab-treated or ocrelizumab-untreated people with primary progressive multiple sclerosis. Ocrelizumab treatment was associated with depletion of circulating B cells and CD20dim CD4+ and CD20dim CD8+ T cells (P < 0.0001, P = 0.0016 and P = 0.0008, respectively) but, in cerebrospinal fluid, only with lower proportions of B cells and CD20dim memory CD4+ T cells (P < 0.0001 and P = 0.0043, respectively). The proportional prevalence of cerebrospinal fluid CD20dim memory CD8+ T cells was not significantly reduced (P = 0.1333). Only in cerebrospinal fluid, the proportions of CD20dim cells within CD4+ and not CD8+ T cells positive for CCR5, CCR6 and CXCR3 were reduced in ocrelizumab-treated participants. The proportion of CD20dim CD4+ T cells and abundance of CD4+ relative to CD8+ T cells in cerebrospinal fluid correlated positively with age (R = 0.6799, P = 0.0150) and Age-Related Multiple Sclerosis Severity score (R = 0.8087, P = 0.0014), respectively. We conclude that, in contrast to cerebrospinal fluid CD20dim CD8+ T cells, B cells and CD20dim CD4+ T cells are reduced in cerebrospinal fluid of people with primary progressive multiple sclerosis with an ocrelizumab-associated depletion of circulating B cells and CD20dim T cells. Therefore, these cells are likely to contribute to the therapeutic effects of ocrelizumab in people with primary progressive multiple sclerosis.

Carnosine synthase deficiency aggravates neuroinflammation in multiple sclerosis

Multiple sclerosis (MS) pathology features autoimmune-driven neuroinflammation, demyelination, and failed remyelination. Carnosine is a histidine-containing dipeptide (HCD) with pluripotent homeostatic properties that is able to improve outcomes in an animal MS model (EAE) when supplied exogenously. To uncover if endogenous carnosine is involved in, and protects against, MS-related neuroinflammation, demyelination or remyelination failure, we here studied the HCD-synthesizing enzyme carnosine synthase (CARNS1) in human MS lesions and two preclinical mouse MS models (EAE, cuprizone). We demonstrate that due to its presence in oligodendrocytes, CARNS1 expression is diminished in demyelinated MS lesions and mouse models mimicking demyelination/inflammation, but returns upon remyelination. Carns1-KO mice that are devoid of endogenous HCDs display exaggerated neuroinflammation and clinical symptoms during EAE, which could be partially rescued by exogenous carnosine treatment. Worsening of the disease appears to be driven by a central, not peripheral immune-modulatory, mechanism possibly linked to impaired clearance of the reactive carbonyl acrolein in Carns1-KO mice. In contrast, CARNS1 is not required for normal oligodendrocyte precursor cell differentiation and (re)myelin to occur, and neither endogenous nor exogenous HCDs protect against cuprizone-induced demyelination. In conclusion, the loss of CARNS1 from demyelinated MS lesions can aggravate disease progression through weakening the endogenous protection against neuroinflammation.

Real world study of ocrelizumab in multiple sclerosis: Kuwait experience

BACKGROUND

Ocrelizumab is a humanized anti-CD20 antibody that has been approved for the treatment of patients with multiple sclerosis (MS). Real-world data in the Middle East is very limited.

OBJECTIVES

To describe the effectiveness and safety of ocrelizumab treatment in MS patients in a real clinical setting.

METHODS

This is an observational, registry-based study. MS patients who were treated with ocrelizumab and completed at least one-year follow-up post-treatment were included. Baseline clinical and radiological characteristics were collected before ocrelizumab initiation. The relapse rate, disability measures, magnetic resonance image (MRI) activity (new T2 lesions and/or GD+ enhancing T1 lesions), and adverse events (AE) at the last follow-up visits were assessed.

RESULTS

Data from 447 patients were analyzed, of which 260 (58.2%) were females. The mean age and mean disease duration were 37.39 ± 11.61 and 9.38 ± 7.57 years respectively. Most of the cohort was of a relapsing form (74.3%; n = 332), whereas active secondary and primary progressive forms represented 15.4% (n = 69) and 10.3% (n = 46) respectively. In the relapsing cohort, Ocrelizumab was prescribed in 162 (48.8%) patients due to highly active disease, and in 99 (29.8%) patients due to disease breakthrough while on prior therapies. In the last follow-up visits, most of the relapsing cohort was relapse-free (95.8% vs. 27.4%; p <0.001), had no evidence of MRI activity (3.6% vs. 67.5%; p <0.001) while EDSS score was stable (1.80+1.22 vs. 1.87+1.16; p < 0.104) when compared to baseline. NEDA-3 was achieved in 302 (91%) of RRMS patients. Confirmed disability progression was 27.5% and 23.9% in SPMS and PPMS respectively. Adverse events were observed in 139 (31.1%); infusion reactions and infections represented the most.

CONCLUSION

This study showed that ocrelizumab is an effective and safe treatment for MS patients in a real clinical setting similar to what was observed in clinical trials.

CD8+ T cells recognizing a neuron-restricted antigen injure axons in a model of multiple sclerosis

CD8+ T cells outnumber CD4+ cells in multiple sclerosis (MS) lesions associated with disease progression, but the pathogenic role and antigenic targets of these clonally expanded effectors are unknown. Based on evidence that demyelination is necessary but not sufficient for disease progression in MS, we previously hypothesized that CNS-infiltrating CD8+ T cells specific for neuronal antigens directly drive the axonal and neuronal injury that leads to cumulative neurologic disability in patients with MS. We now show that demyelination induced expression of MHC class I on neurons and axons and resulted in presentation of a neuron-specific neoantigen (synapsin promoter-driven chicken ovalbumin) to antigen-specific CD8+ T cells (anti-ovalbumin OT-I TCR-transgenic T cells). These neuroantigen-specific effectors surveilled the CNS in the absence of demyelination but were not retained. However, upon induction of demyelination via cuprizone intoxication, neuroantigen-specific CD8+ T cells proliferated, accumulated in the CNS, and damaged neoantigen-expressing neurons and axons. We further report elevated neuronal expression of MHC class I and β2-microglobulin transcripts and protein in gray matter and white matter tracts in tissue from patients with MS. These findings support a pathogenic role for autoreactive anti-axonal and anti-neuronal CD8+ T cells in MS progression.

A prospective observational longitudinal study with a two-year follow-up of multiple sclerosis patients on Cladribine

BACKGROUND

Cladribine was approved for the treatment of multiple sclerosis (MS). Real-world data is very limited.

OBJECTIVES

To study the effectiveness and the safety of Cladribine treatment in only one group of MS patients after treatment with Cladribine for two years.

METHODS

This observational, longitudinal prospective study. Eligible subjects were relapsing remitting MS patients who had at least two-year follow-up after Cladribine treatment. The primary endpoint was the proportion of relapse free patients. Secondary endpoints were ARR, change in EDSS scores, the proportion of patients with CDP, MRI activity, and NEDA-3 status, also the rate of occurrence of AEs. Patients were assessed for primary and secondary endpoints at the end of two years of follow-up.

RESULTS

Of a total of seventy-two patients, 59 (81.9 %) were females, mean age of 36.32 + 10.06 years old, mean disease duration 7.21 + 6.19. Most patients (n = 32; 44.4 %) were naïve to any treatment. Forty patients (55.6 %) completed two courses of treatment. The primary endpoint showed that most of our cohort was relapse free (85 % versus 25 %; P < 0.001), Secondary endpoints showed that ARR was significantly reduced 0.15 + 0.36 versus 0.85 + 0.53; P < 0.01). Most of the cohort 90 % have no progression of disability. Few subjects had new T2 lesions (7.5 % versus 70.8 %; P < 0.001 and gadolinium enhancement 5 % versus 66.7 %; P < 0.001) in MRI compared to baseline. No evidence of disease activity 3 (NEDA-3) was achieved in 30 (75 %) patients. It was achieved in 87.5 % of naive patients versus 66.7 % in patients who received prior disease modification drugs before Cladribine initiation. Infections 6 (n = 6; 8.4 %) lymphocytopenia (n = 3; 4.2 %), and elevated liver enzymes (n = 1; 1.4 %) were reported.

CONCLUSION

Cladribine treatment reduced significantly relapse rate and MRI activity. It was safe and tolerable. Early initiation of cladribine is associated with favorable outcomes.

Neural Cells for Neurodegenerative Diseases in Clinical Trials

Neurodegenerative diseases (ND) are an entire spectrum of clinical conditions that affect the central and peripheral nervous system. There is no cure currently, with treatment focusing mainly on slowing down progression or symptomatic relief. Cellular therapies with various cell types from different sources are being conducted as clinical trials for several ND diseases. They include neural, mesenchymal and hemopoietic stem cells, and neural cells derived from embryonic stem cells and induced pluripotent stem cells. In this review, we present the list of cellular therapies for ND comprising 33 trials that used neural stem progenitors, 8 that used differentiated neural cells ,and 109 trials that involved non-neural cells in the 7 ND. Encouraging results have been shown in a few early-phase clinical trials that require further investigations in a randomized setting. However, such definitive trials may not be possible given the relative cost of the trials, and in the setting of rare diseases.

The Blood Concentration of Metallic Nanoparticles Is Related to Cognitive Performance in People with Multiple Sclerosis: An Exploratory Analysis

The imbalance in the concentration of metallic nanoparticles has been demonstrated to play an important role in multiple sclerosis (MS), which may impact cognition. Biomarkers are needed to provide insights into the pathogenesis and diagnosis of MS. They can be used to gain a better understanding of cognitive decline in people with MS (pwMS). In this study, we investigated the relationship between the blood concentration of metallic nanoparticles (blood nanoparticles) and cognitive performance in pwMS. First, four mL blood samples, clinical characteristics, and cognitive performance were obtained from 21 pwMS. All participants had relapse-remitting MS, with a score of ≤4.5 points in the expanded disability status scale. They were relapse-free in the three previous months from the day of collection and had no orthopedic, muscular, cardiac, and cerebellar diseases. We quantified the following metallic nanoparticles: aluminum, chromium, copper, iron, magnesium, nickel, zinc, and total concentration. Cognitive performance was measured by mini-mental state examination (MMSE) and the symbol digit modalities test (SDMT). Pearson's and Spearman's correlation coefficients and stepwise linear regression were calculated to assess the relationship between cognitive performance and blood nanoparticles. We found that better performance in SDMT and MMSE was related to higher total blood nanoparticles (r = 0.40; p < 0.05). Also, better performance in cognitive processing speed and attention (SDMT) and mental state (MMSE) were related to higher blood iron (r = 0.44; p < 0.03) and zinc concentrations (r = 0.41; p < 0.05), respectively. The other metallic nanoparticles (aluminum, chromium, copper, magnesium, and nickel) did not show a significant relationship with the cognitive parameters (p > 0.05). Linear regression estimated a significant association between blood iron concentration and SDMT performance. In conclusion, blood nanoparticles are related to cognitive performance in pwMS. Our findings suggest that the blood concentration of metallic nanoparticles, particularly the iron concentration, is a promising biomarker for monitoring cognitive impairment in pwMS.

Mesenchymal stromal cell-derived secretome-based therapy for neurodegenerative diseases: overview of clinical trials

BACKGROUND

Over the past few years, mesenchymal stromal cells (MSCs) have attracted a great deal of scientific attention owing to their promising results in the treatment of incurable diseases. However, there are several concerns about their possible side effects after direct cell transplantation, including host immune response, time-consuming cell culture procedures, and the dependence of cell quality on the donor, which limit the application of MSCs in clinical trials. On the other hand, it is well accepted that the beneficial effects of MSCs are mediated by secretome rather than cell replacement. MSC secretome refers to a variety of bioactive molecules involved in different biological processes, specifically neuro-regeneration.

MAIN BODY

Due to the limited ability of the central nervous system to compensate for neuronal loss and relieve disease progress, mesenchymal stem cell products may be used as a potential cure for central nervous system disorders. In the present study, the therapeutic effects of MSC secretome were reviewed and discussed the possible mechanisms in the three most prevalent central nervous system disorders, namely Alzheimer's disease, multiple sclerosis, and Parkinson's disease. The current work aimed to help discover new medicine for the mentioned complications.

CONCLUSION

The use of MSC-derived secretomes in the treatment of the mentioned diseases has encouraging results, so it can be considered as a treatment option for which no treatment has been introduced so far.

Saliva and Serum Acetylcholinesterase Activity in Multiple Sclerosis

Multiple sclerosis is mediated by the immune system that damages the myelin sheath. Most patients experience inflammation. Since one of the factors that have a role in reducing inflammation is acetylcholine, and according to the benefits of saliva, in this study, the level of salivary and serum cholinesterase activity in patients with multiple sclerosis and healthy were evaluated. Thirty women with multiple sclerosis who were hospitalized in the neurology ward of Imam Reza and Hazrat Rasoul Hospitals and 30 healthy females participated in the study. The severity of multiple sclerosis was calculated by expanded disability status scale (EDSS). Saliva and serum samples were collected in the morning. Cholinesterase activity was assessed by a photometric method. The mean cholinesterase activity in stimulated and unstimulated saliva and serum significantly reduced in the multiple sclerosis group. The cutoff for differentiation of multiple sclerosis patients from healthy individuals by assessing cholinesterase activity (IU/L) was 3577 in serum, 241 in unstimulated saliva, and 266 in stimulated saliva. It seems that cholinesterase activity decreases in patients with multiple sclerosis.

A real-life study of alemtuzumab in persons with multiple sclerosis: Kuwait's experience

BACKGROUND

Alemtuzumab, a humanized anti-CD52 monoclonal antibody, has been approved as a treatment in persons with active relapsing-remitting multiple sclerosis (RRMS). Real-world data in middle east is very limited. We aimed to evaluate the effectiveness and safety of alemtuzumab in a real-world clinical setting.

METHODS

This observational, registry based study assessed persons with multiple sclerosis (PwMS) who were treated with alemtuzumab and completed at least follow up one year after second course. Baseline clinical and radiological characteristics within one year prior to alemtuzumab initiation were collected. The relapse rate, disability measures, radiological activity and adverse events at last follow-up visits were assessed.

RESULTS

Data of seventy-three persons with multiple sclerosis (MS) was analyzed, of which 53 (72.6%) were females. Mean age and mean disease duration were 34.25 ± 7.62 and 9.23 ± 6.20 years respectively. Alemtuzumab was started in 32 (43.8%) naïve patients due to highly active disease and in 25 (34.2%) (PwMS) who were on prior therapies and  in 16 (22%) patients due to adverse events on prior medications. Mean follow-up period was 4 ± 1.67 years. In the last follow-up visits, most of our cohort was relapse free (79.5% vs. 17.8%; p < 0.001) compared to baseline before alemtuzumab treatment while mean EDSS score was reduced (2.21 ± 2.15 vs. 2.41 ± 1.85; p < 0.059). The proportion of PwMS who had MRI activity (new T2/ Gd-enhancing) lesions were significantly reduced compared to baseline (15.1% vs. 82.2%; p < 0.001). NEDA-3 was achieved in 57.5% of (PwMS). NEDA-3 was significantly better in naïve patients (78% versus. 41.5%; p < 0.002) and in patients with disease duration < 5 years, (82.6% v 43.2%; p < 0.002). Several adverse events such as infusion reactions (75.3%), autoimmune thyroiditis (16.4%) and glomerulonephritis (2.7%) were reported.

CONCLUSION

The effectiveness and safety profile of alemtuzumab in this cohort were consistent with data of clinical trials. Early initiation of Alemtuzumab is associated with favorable outcome.

Mechanisms of antigen-induced reversal of CNS inflammation in experimental demyelinating disease

Autoimmune central nervous system (CNS) demyelinating diseases are a major public health burden and poorly controlled by current immunosuppressants. More precise immunotherapies with higher efficacy and fewer side effects are sought. We investigated the effectiveness and mechanism of an injectable myelin-based antigenic polyprotein MMPt (myelin oligodendrocyte glycoprotein, myelin basic protein and proteolipid protein, truncated). We find that it suppresses mouse experimental autoimmune encephalomyelitis without major side effects. MMPt induces rapid apoptosis of the encephalitogenic T cells and suppresses inflammation in the affected CNS. Intravital microscopy shows that MMPt is taken up by perivascular F4/80⁺ cells but not conventional antigen-presenting dendritic cells, B cells, or microglia. MMPt-stimulated F4/80⁺ cells induce reactive T cell immobilization and apoptosis in situ, resulting in reduced infiltration of inflammatory cells and chemokine production. Our study reveals alternative mechanisms that explain how cognate antigen suppresses CNS inflammation and may be applicable for effectively and safely treating demyelinating diseases.

Multiple sclerosis: role of meningeal lymphoid aggregates in progression independent of relapse activity

The emphasis on mechanisms driving multiple sclerosis (MS) symptomatic worsening suggests that we move beyond categorical clinical classifiers such as relapsing-remitting MS (RR-MS) and progressive MS (P-MS). Here, we focus on the clinical phenomenon progression independent of relapse activity (PIRA), which begins early in the disease course. PIRA occurs throughout MS, becoming more phenotypically evident as patients age. The underlying mechanisms for PIRA include chronic-active demyelinating lesions (CALs), subpial cortical demyelination, and nerve fiber injury following demyelination. We propose that much of the tissue injury associated with PIRA is driven by autonomous meningeal lymphoid aggregates, present before disease onset and unresponsive to current therapeutics. Recently, specialized magnetic resonance imaging (MRI) has identified and characterized CALs as paramagnetic rim lesions in humans, enabling novel radiographic-biomarker-clinical correlations to further understand and treat PIRA.

Selective PDE4 subtype inhibition provides new opportunities to intervene in neuroinflammatory versus myelin damaging hallmarks of multiple sclerosis

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) characterized by focal inflammatory lesions and prominent demyelination. Even though the currently available therapies are effective in treating the initial stages of disease, they are unable to halt or reverse disease progression into the chronic progressive stage. Thus far, no repair-inducing treatments are available for progressive MS patients. Hence, there is an urgent need for the development of new therapeutic strategies either targeting the destructive immunological demyelination or boosting endogenous repair mechanisms. Using in vitro, ex vivo, and in vivo models, we demonstrate that selective inhibition of phosphodiesterase 4 (PDE4), a family of enzymes that hydrolyzes and inactivates cyclic adenosine monophosphate (cAMP), reduces inflammation and promotes myelin repair. More specifically, we segregated the myelination-promoting and anti-inflammatory effects into a PDE4D- and PDE4B-dependent process respectively. We show that inhibition of PDE4D boosts oligodendrocyte progenitor cells (OPC) differentiation and enhances (re)myelination of both murine OPCs and human iPSC-derived OPCs. In addition, PDE4D inhibition promotes in vivo remyelination in the cuprizone model, which is accompanied by improved spatial memory and reduced visual evoked potential latency times. We further identified that PDE4B-specific inhibition exerts anti-inflammatory effects since it lowers in vitro monocytic nitric oxide (NO) production and improves in vivo neurological scores during the early phase of experimental autoimmune encephalomyelitis (EAE). In contrast to the pan PDE4 inhibitor roflumilast, the therapeutic dose of both the PDE4B-specific inhibitor A33 and the PDE4D-specific inhibitor Gebr32a did not trigger emesis-like side effects in rodents. Finally, we report distinct PDE4D isoform expression patterns in human area postrema neurons and human oligodendroglia lineage cells. Using the CRISPR-Cas9 system, we confirmed that pde4d1/2 and pde4d6 are the key targets to induce OPC differentiation. Collectively, these data demonstrate that gene specific PDE4 inhibitors have potential as novel therapeutic agents for targeting the distinct disease processes of MS.

Multiple Sclerosis: Inflammatory and Neuroglial Aspects

Multiple sclerosis (MS) represents the most common acquired demyelinating disorder of the central nervous system (CNS). Its pathogenesis, in parallel with the well-established role of mechanisms pertaining to autoimmunity, involves several key functions of immune, glial and nerve cells. The disease's natural history is complex, heterogeneous and may evolve over a relapsing-remitting (RRMS) or progressive (PPMS/SPMS) course. Acute inflammation, driven by infiltration of peripheral cells in the CNS, is thought to be the most relevant process during the earliest phases and in RRMS, while disruption in glial and neural cells of pathways pertaining to energy metabolism, survival cascades, synaptic and ionic homeostasis are thought to be mostly relevant in long-standing disease, such as in progressive forms. In this complex scenario, many mechanisms originally thought to be distinctive of neurodegenerative disorders are being increasingly recognized as crucial from the beginning of the disease. The present review aims at highlighting mechanisms in common between MS, autoimmune diseases and biology of neurodegenerative disorders. In fact, there is an unmet need to explore new targets that might be involved as master regulators of autoimmunity, inflammation and survival of nerve cells.

Oxidative stress in multiple sclerosis-Emerging imaging techniques

While conventional magnetic resonance imaging (MRI) is central to the evaluation of patients with multiple sclerosis, its role in detecting the pathophysiology underlying neurodegeneration is more limited. One of the common outcome measures for progressive multiple sclerosis trials, atrophy on brain MRI, is non-specific and reflects end-stage changes after considerable neurodegeneration has occurred. Identifying biomarkers that identify processes underlying neurodegeneration before it is irreversible and that reflect relevant neurodegenerative pathophysiology is an area of significant need. Accumulating evidence suggests that oxidative stress plays a major role in the pathogenesis of multiple neurodegenerative diseases, including multiple sclerosis. Imaging markers related to inflammation, myelination, and neuronal integrity have been areas of advancement in recent years but oxidative stress has remained an area of unrealized potential. In this article we will begin by reviewing the role of oxidative stress in the pathogenesis of multiple sclerosis. Chronic inflammation appears to be directly related to the increased production of reactive oxygen species and the effects of subsequent oxidative stress appear to be amplified by aging and accumulating disease. We will then discuss techniques in development used in the assessment of MS as well as other models of neurodegenerative disease in which oxidative stress is implicated. Multiple blood and CSF markers of oxidative stress have been evaluated in subjects with MS, but non-invasive imaging offers major upside in that it provides real-time assessment within the brain.

The immunology of multiple sclerosis

Our incomplete understanding of the causes and pathways involved in the onset and progression of multiple sclerosis (MS) limits our ability to effectively treat this complex neurological disease. Recent studies explore the role of immune cells at different stages of MS and how they interact with cells of the central nervous system (CNS). The findings presented here begin to question the exclusivity of an antigen-specific cause and highlight how seemingly distinct immune cell types can share common functions that drive disease. Innovative techniques further expose new disease-associated immune cell populations and reinforce how environmental context is critical to their phenotype and subsequent role in disease. Importantly, the differentiation of immune cells into a pathogenic state is potentially reversible through therapeutic manipulation. As such, understanding the mechanisms that provide plasticity to causal cell types is likely key to uncoupling these disease processes and may identify novel therapeutic targets that replace the need for cell ablation.

Individual differences in visual evoked potential latency are associated with variance in brain tissue volume in people with multiple sclerosis: An analysis of brain function-structure correlates

Visual evoked potentials (VEP) index visual pathway functioning, and are often used for clinical assessment and as outcome measures in people with multiple sclerosis (PwMS). VEPs may also reflect broader neural disturbances that extend beyond the visual system, but this possibility requires further investigation. In the present study, we examined the hypothesis that delayed latency of the P100 component of the VEP would be associated with broader structural changes in the brain in PwMS. We obtained VEP latency for a standard pattern-reversal checkerboard stimulus paradigm, in addition to Magnetic Resonance Imaging (MRI) measures of whole brain volume (WBV), gray matter volume (GMV), white matter volume (WMV), and T2-weighted fluid attenuated inversion recovery (FLAIR) white matter lesion volume (FLV). Correlation analyses indicated that prolonged VEP latency was significantly associated with lower WBV, GMV, and WMV, and greater FLV. VEP latency remained significantly associated with WBV, GMV, and WMV even after controlling for the variance associated with inter-ocular latency, age, time between VEP and MRI assessments, and other MRI variables. VEP latency delays were most pronounced in PwMS that exhibited low volume in both white and gray matter simultaneously. Furthermore, PwMS that had delayed VEP latency based on a clinically relevant cutoff (VEP latency ≥ 113 ms) in both eyes had lower WBV, GMV, and WMV and greater FLV in comparison to PwMS that had normal VEP latency in one or both eyes. The findings suggest that PwMS that have delayed latency in both eyes may be particularly at risk for exhibiting greater brain atrophy and lesion volume. These analyses also indicate that VEP latency may index combined gray matter and white matter disturbances, and therefore broader network connectivity and efficiency. VEP latency may therefore provide a surrogate marker of broader structural disturbances in the brain in MS.

Secondary progressive multiple sclerosis: A national consensus paper on diagnostic criteria

BACKGROUND

In clinical practice, the diagnosis of secondary progressive multiple sclerosis (SPMS) is often delayed, retrospective and non-reproducible, as there are no consensus criteria that define the advent of SPMS. Early identification of SPMS is essential to improve patient care.

METHODS

Eight regional board meetings in France involving 56 multiple sclerosis (MS) experts (neurologists) were convened to discuss diagnostic criteria for SPMS. Subsequently, a national board meeting of 13 neurologists (with an expert representing each geographical region) was held to review points of convergence or divergence between regions and to develop a national consensus document.

RESULTS

Based on the discussions from the regional boards, the MS experts at the national board retained the worsening of the EDSS score, with compatible clinical features, as the only consensus criterion for the diagnosis of SPMS in clinical practice. The patient should have experienced during at least the previous 6 months and in the absence of any relapse, a worsening in the EDSS score of +1.0 point (if the previous EDSS was≤5.0) or of +0.5 point (if the previous EDSS was≥5.5), with a pyramidal or cerebellar functional system score≥2 and without setting a minimum EDSS score; or, in case of a stable EDSS score≥4.0, a worsening of a functional score. This worsening should be confirmed within 3 to 6 months. According to the MS experts, the patient's age, duration of illness and a minimal threshold EDSS score are only risk factors for transition to SPMS. Patient reports during consultation and cognitive impairment are important warning signs, which should trigger an objective assessment with specific tests or closer monitoring. Clinical relapse and/or MRI activities are non-discriminatory for making the diagnosis of SPMS.

CONCLUSIONS

The experts defined precise diagnostic criteria adapted to clinical practice for earlier identification of SPMS, paving the way for better management of this stage of the disease.

Shared decision-making in patients with multiple sclerosis

Multiple sclerosis (MS) is a chronic and progressive neurological disorder impacting physical, cognitive, and psychosocial health. The disease course, severity, and presence of symptoms differ within and between persons over time and are unpredictable. Given the preference-sensitive nature of many key decisions to be made, and the increasing numbers of disease-modifying therapies, shared decision-making (SDM) with patients seems to be key in offering optimum care and outcomes for people suffering from MS. In this paper, we describe our perspective on how to achieve SDM in patients with MS, following key SDM-elements from established SDM-frameworks. As for deliberation in the clinical encounter, SDM communication training of professionals and feedback on their current performance are key aspects, as well as encouraging patients to participate. Concerning information for patients, it is important to provide balanced, evidence-based information about the benefits and the harms of different treatment options, including the option of surveillance only. At the same time, attention is needed for the optimal dosage of that information, given the symptoms of cognitive dysfunction and fatigue among MS-patients, and the uncertainties they have to cope with. Finally, for broader communication, a system is required that assures patient preferences are actually implemented by multidisciplinary MS-teams. As SDM is also being implemented in many countries within the context of value-based health care, we consider the systematic use of outcome information, such as patient-reported outcome measures (PROMs) and Patient Decision Aids, as an opportunity to achieve SDM.

How is neuromuscular fatigability affected by perceived fatigue and disability in people with multiple sclerosis?

Whereas fatigue is recognized to be the main complaint of patients with multiple sclerosis (PwMS), its etiology, and particularly the role of resistance to fatigability and its interplay with disability level, remains unclear. The purposes of this review were to (i) clarify the relationship between fatigue/disability and neuromuscular performance in PwMS and (ii) review the corticospinal and muscular mechanisms of voluntary muscle contraction that are altered by multiple sclerosis, and how they may be influenced by disability level or fatigue. Neuromuscular function at rest and during exercise are more susceptible to impairement, due to deficits in voluntary activation, when the disability is greater. Fatigue level is related to resistance to fatigability but not to neuromuscular function at rest. Neurophysiological parameters related to signal transmission such as central motor conduction time, motor evoked potentials amplitude and latency are affected by disability and fatigue levels but their relative role in the impaired production of torque remain unclear. Nonetheless, cortical reorganization represents the most likely explanation for the heightened fatigability during exercise for highly fatigued and/or disabled PwMS. Further research is needed to decipher how the fatigue and disability could influence fatigability for an ecological task, especially at the corticospinal level.

Altered muscle oxidative phenotype impairs exercise tolerance but does not improve after exercise training in multiple sclerosis

BACKGROUND

Patients with multiple sclerosis (MS) experience reduced exercise tolerance that substantially reduces quality of life. The mechanisms underpinning exercise intolerance in MS are not fully clear. This study aimed to determine the contributions of the cardiopulmonary system and peripheral muscle in MS-induced exercise intolerance before and after exercise training.

METHODS

Twenty-three patients with MS (13 women) and 20 age-matched and sex-matched healthy controls (13 women) performed a cardiopulmonary exercise test. Muscle fibre type composition, size, succinate dehydrogenase (SDH) activity, capillarity, and gene expression and proteins related to mitochondrial density were determined in vastus lateralis muscle biopsies. Nine MS patients (five women) were re-examined following a 12 week exercise training programme consisting of high-intensity cycling interval and resistance training.

RESULTS

Patients with MS had lower maximal oxygen uptake compared with healthy controls (V̇O_2peak , 25.0 ± 8.5 vs. 35.7 ± 6.4 mL/kg/min, P < 0.001). The lower gas exchange threshold (MS: 14.5 ± 5.5 vs. controls: 19.7 ± 2.9 mL/kg/min, P = 0.01) and slope of V̇O₂ versus work rate (MS: 9.5 ± 1.7 vs. controls: 10.8 ± 1.1 mL/min/W, P = 0.01) suggested an intramuscular contribution to exercise intolerance in patients with MS. Muscle SDH activity was 22% lower in MS (P = 0.004), and strongly correlated with several indices of whole-body exercise capacity in MS patients (e.g. V̇O_2peak , Spearman's ρ = 0.81, P = 0.002), but not healthy controls (ρ = 0.24, P = 0.38). In addition, protein levels of mitochondrial OXPHOS complexes I (-40%, P = 0.047) and II (-45%, P = 0.026) were lower in MS patients versus controls. Muscle capillary/fibre ratio correlated with V̇O_2peak in healthy controls (ρ = 0.86, P < 0.001) but not in MS (ρ = 0.35, P = 0.22), and did not differ between groups (1.41 ± 0.30 vs. 1.47 ± 0.38, P = 0.65). Expression of genes involved in mitochondrial function, such as PPARA, PPARG, and TFAM, was markedly reduced in muscle tissue samples of MS patients (all P < 0.05). No differences in muscle fibre type composition or size were observed between groups (all P > 0.05). V̇O_2peak increased by 23% following exercise training in MS (P < 0.001); however, no changes in muscle capillarity, SDH activity, gene or protein expression were observed (all P > 0.05).

CONCLUSIONS

Skeletal muscle oxidative phenotype (mitochondrial complex I and II content, SDH activity) is lower in patients with MS, contributing to reduced exercise tolerance. However, skeletal muscle mitochondria appeared resistant to the beneficial effects of exercise training, suggesting that other physiological systems, at least in part, drive the improvements in exercise capacity following exercise training in MS.

Thyroid hormone-dependent oligodendroglial cell lineage genomic and non-genomic signaling through integrin receptors

Multiple sclerosis (MS) is a heterogeneous autoimmune disease whereby the pathological sequelae evolve from oligodendrocytes (OLs) within the central nervous system and are targeted by the immune system, which causes widespread white matter pathology and results in neuronal dysfunction and neurological impairment. The progression of this disease is facilitated by a failure in remyelination following chronic demyelination. One mediator of remyelination is thyroid hormone (TH), whose reliance on monocarboxylate transporter 8 (MCT8) was recently defined. MCT8 facilitates the entry of THs into oligodendrocyte progenitor cell (OPC) and pre-myelinating oligodendrocytes (pre-OLs). Patients with MS may exhibit downregulated MCT8 near inflammatory lesions, which emphasizes an inhibition of TH signaling and subsequent downstream targeted pathways such as phosphoinositide 3-kinase (PI3K)-Akt. However, the role of the closely related mammalian target of rapamycin (mTOR) in pre-OLs during neuroinflammation may also be central to the remyelination process and is governed by various growth promoting signals. Recent research indicates that this may be reliant on TH-dependent signaling through β1-integrins. This review identifies genomic and non-genomic signaling that is regulated through mTOR in TH-responsive pre-OLs and mature OLs in mouse models of MS. This review critiques data that implicates non-genomic Akt and mTOR signaling in response to TH-dependent integrin receptor activation in pre-OLs. We have also examined whether this can drive remyelination in the context of neuroinflammation and associated sequelae. Importantly, we outline how novel therapeutic small molecules are being designed to target integrin receptors on oligodendroglial lineage cells and whether these are viable therapeutic options for future use in clinical trials for MS.

Effects of Different Exercise Therapies on Balance Function and Functional Walking Ability in Multiple Sclerosis Disease Patients-A Network Meta-Analysis of Randomized Controlled Trials

The objective of this research is to assess the effects of seven different exercise therapies (aquatic exercise, aerobic exercise, yoga, Pilates, virtual reality exercise, whole-body vibration exercise, and resistance exercise) on the balance function and functional walking ability of multiple sclerosis disease patients. Materials and Methods: The effects of different exercise interventions on the balance function and functional walking ability in people with multiple sclerosis were assessed by searching five databases: PubMed, Embase, Cochrane Library, Web of Science, and CNKI; only randomized controlled trials were included. The included studies were assessed for risk of bias using the Cochrane assessment tool. Results: The RCTs were collected between the initial date of the electronic databases’ creation and May 2022. We included 31 RCTs with 904 patients. The results of the collected data analysis showed that yoga can significantly improve patients’ BBS scores (SUCRA = 79.7%) and that aquatic exercise can significantly decrease patients’ TUG scores (SUCRA = 78.8%). Conclusion: Based on the network meta-analysis, we suggest that although each type of exercise is useful, yoga, virtual reality training, and aerobic training are more effective in improving the balance function of people with MS; aquatic exercise, virtual reality training, and aerobic training are more effective in improving the functional walking ability of people with MS.

Progression in multiple sclerosis - a long-term problem

PURPOSE OF REVIEW

Disability progression in multiple sclerosis (MS) is strongly linked to central nervous system (CNS)-specific pathological processes that occur throughout all disease stages, but that become clinically evident in later phases of the disease. We here discuss current views and concepts for targeting progressive MS.

RECENT FINDINGS

Detailed clinical assessment of MS patients has identified an even closer entanglement of relapse-remitting and progressive disease, leading to novel concepts such as 'progression independent of relapse activity'. Evolving clinical concepts together with a focus on molecular (neurofilament light chain) and imaging (paramagnetic rim lesions) biomarkers might specifically identify patients at risk of developing progressive MS considerably earlier than before. A multitude of novel treatment approaches focus either on direct neuroaxonal protection or myelin regeneration or on beneficially modulating CNS-intrinsic or innate immune inflammation. Although some long-awaited trials have recently been unsuccessful, important lessons could still be drawn from novel trial designs providing frameworks for future clinical studies.

SUMMARY

Targeting progressive disease biology and repairing established damage is the current central challenge in the field of MS. Especially, the compartmentalized adaptive and innate CNS inflammation is an attractive target for novel approaches, probably as a combinatory approach together with neuroprotective or myelin regenerating strategies.

Is the effect of drugs in progressive MS only due to an effect on inflammation? A subgroup meta-analysis of randomised trials

BACKGROUND

It is unclear whether drugs approved for the treatment of progressive multiple sclerosis (PMS) are effective in disability progression only because of their effect on the inflammatory component of the disease.

OBJECTIVE

This meta-analysis aimed to evaluate whether the benefits of PMS treatments are mediated by its effect on the active component of the disease.

METHODS

We conducted a systematic search to identify randomised, double-blind, placebo-controlled trials evaluating the efficacy of disease-modifying therapies on disability progression for primary or secondary PMS. The primary endpoint of the analysis was disability progression based on the expanded disability status scale. A subgroup meta-analysis evaluated the effects of treatment according to disease activity at baseline.

RESULTS

Twelve trials (a total of 8659 PMS cases) were selected. Analysis of the included trials demonstrated that treatment benefit appears to be mainly confined to the group with active disease (hazard ratio (HR) = 0.67; 95% confidence interval (CI): 0.58-0.79) as compared to the group with inactive disease (HR = 0.90; 95% CI: 0.79-1.02, interaction test: p = 0.005).

CONCLUSIONS

This study showed that the benefit of treating patients with PMS was mostly confined to those with the more active disease. Drugs targeting specific pathological processes leading to disability progression remain necessary.

Blood Neurofilament Light in Progressive Multiple Sclerosis: Post Hoc Analysis of 2 Randomized Controlled Trials

OBJECTIVE

To investigate the potential of plasma neurofilament light (pNfL) as a biomarker of disease progression and treatment response in progressive multiple sclerosis (PMS) with and without acute disease activity.

METHODS

Post hoc blinded analysis of pNfL levels in two placebo-controlled, phase 3 studies in secondary progressive MS (SPMS; EXPAND) and primary progressive MS (PPMS; INFORMS) using siponimod and fingolimod, respectively, as active compounds. pNfL levels were quantified using a single molecule array ("Homebrew" Simoa) immunoassay from stored EDTA plasma samples of all patients who consented for exploratory biomarker analysis in either study; pNfL levels were divided into high (≥30 pg/mL) and low (<30 pg/mL) at baseline (BL). We investigated the association of pNfL levels with disability progression, cognitive decline and brain atrophy, and their sensitivity to indicate treatment response vis-à-vis clinical measures.

RESULTS

We analyzed pNfL in 4185 samples from 1452 SPMS patients and 1172 samples from 378 PPMS patients. BL pNfL levels were higher in SPMS (geomean 32.1pg/mL) than in PPMS (22.0pg/mL; p<0.0001) patients. In both studies, higher BL pNfL levels were associated with older age, higher EDSS score, more Gd⁺ lesions, and higher T2 lesion load (all p<0.05). Independent of treatment, high versus low BL pNfL levels were associated with significantly higher risks of confirmed 3-month (SPMS [32%], HR [95%CI]: 1.32 [1.09;1.61]; PPMS [49%], 1.49 [1.05;2.12]) and 6-month disability progression (SPMS [26%], 1.26 [1.01;1.57]; PPMS [48%], 1.48 [1.01;2.17]), earlier wheelchair dependence (SPMS [50%], 1.50 [0.96;2.34]; PPMS [197%], 2.97 [1.44;6.10]), cognitive decline (SPMS [41%], 1.41 [1.09;1.84]) and higher rates of brain atrophy (mean change at month [M]24: SPMS, -0.92; PPMS, -1.39). BL pNfL levels were associated with future disability progression and the degree of brain atrophy regardless of presence or absence of acute disease activity (gadolinium-enhancing lesions or recent occurrence of relapses before BL). pNfL levels were lower in patients treated with siponimod or fingolimod versus placebo-treated patients and higher in those having experienced disability progression.

CONCLUSION

pNfL was associated with future clinical and radiological disability progression features at the group level. pNfL was reduced by treatment and may be a meaningful outcome measure in PMS studies.

Long Noncoding RNAs in CNS Myelination and Disease

Myelination by oligodendrocytes is crucial for neuronal survival and function, and defects in myelination or failure in myelin repair can lead to axonal degeneration and various neurological diseases. At present, the factors that promote myelination and overcome the remyelination block in demyelinating diseases are poorly defined. Although the roles of protein-coding genes in oligodendrocyte differentiation have been extensively studied, the majority of the mammalian genome is transcribed into noncoding RNAs, and the functions of these molecules in myelination are poorly characterized. Long noncoding RNAs (lncRNAs) regulate transcription at multiple levels, providing spatiotemporal control and robustness for cell type-specific gene expression and physiological functions. lncRNAs have been shown to regulate neural cell-type specification, differentiation, and maintenance of cell identity, and dysregulation of lncRNA function has been shown to contribute to neurological diseases. In this review, we discuss recent advances in our understanding of the functions of lncRNAs in oligodendrocyte development and myelination as well their roles in neurological diseases and brain tumorigenesis. A more systematic characterization of lncRNA functional networks will be instrumental for a better understanding of CNS myelination, myelin disorders, and myelin repair.

Antibody Therapies for Progressive Multiple Sclerosis and for Promoting Repair

Progressive multiple sclerosis (PMS) is clinically distinct from relapsing-remitting MS (RRMS). In PMS, clinical disability progression occurs independently of relapse activity. Furthermore, there is increasing evidence that the pathological mechanisms of PMS and RRMS are different. Current therapeutic options for the treatment of PMS remain inadequate, although ocrelizumab, a B-cell-depleting antibody, is now available as the first approved therapeutic option for primary progressive MS. Recent advances in understanding the pathophysiology of PMS provide hope for new innovative therapeutic options: these include antibody therapies with anti-inflammatory, neuroprotective, and/or remyelination-fostering effects. In this review, we summarize the relevant trial data relating to antibody therapy and consider future antibody options for treating PMS.

Efficacy and Safety of Mesenchymal Stem Cell Transplantation in the Treatment of Autoimmune Diseases (Rheumatoid Arthritis, Systemic Lupus Erythematosus, Inflammatory Bowel Disease, Multiple Sclerosis, and Ankylosing Spondylitis): A Systematic Review and Meta-Analysis of Randomized Controlled Trial

Objective

To evaluate the efficacy and safety of mesenchymal stem cell (MSC) transplantation in the treatment of autoimmune diseases.

Methods

The Chinese and English databases were searched for clinical research on the treatment of autoimmune diseases with mesenchymal stem cells. The search time range is from a self-built database to October 1, 2021. Two reviewers independently screened the literature according to the inclusion and exclusion criteria, extracted data, and evaluated the bias of the included studies. RevMan 5.3 analysis software was used for meta-analysis.

Results

A total of 18 RCTs involving 5 autoimmune diseases were included. The 5 autoimmune disease were rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), inflammatory bowel disease, ankylosing spondylitis, and multiple sclerosis. For RA, the current randomized controlled trials (RCTs) still believe that stem cell transplantation may reduce disease activity, improve the clinical symptoms (such as DAS28), and the percentage of CD4+CD 25+Foxp3+Tregs in the response group increased and the percentage of CD4+IL-17A+Th17 cells decreased. The total clinical effective rate of RA is 54%. For SLE, the results showed that mesenchymal stem cell transplantation may improve SLEDAI [-2.18 (-3.62, -0.75), P = 0.003], urine protein [-0.93 (-1.04, -0.81), P < 0.00001], and complement C3 [0.31 (0.19, 0.42), P < 0.00001]. For inflammatory bowel disease, the results showed that mesenchymal stem cell transplantation may improve clinical efficacy [2.50 (1.07, 5.84), P = 0.03]. For ankylosing spondylitis, MSC treatment for 6 months may increase the total effective rate; reduce erythrocyte sedimentation rate, intercellular adhesion molecules, and serum TNF-α; and improve pain and activity. For multiple sclerosis, the current research results are still controversial, so more RCTs are needed to amend or confirm the conclusions. No obvious adverse events of mesenchymal stem cell transplantation were found in all RCTs.

Conclusion

MSCs have a certain effect on different autoimmune diseases, but more RCTs are needed to further modify or confirm the conclusion.

Identify the report as a systematic review

Background: To examine the relationship of vitamin B12 and folate concentrations to cognitive function, fatigue measures, physical function, quality of life (patient-centred outcomes) and homocysteine plasma concentrations (intermediate marker of cobalamin and folate deficiency) for patients with Multiple Sclerosis (MS). Methods: Systematic searches for eligible articles of MEDLINE, CINAHL, EMBASE, Scopus, Web of Science and OpenGray databases were conducted from 1983 in March 2021. Heterogeneity, Weighted Mean Difference (WMD) and Confidence Intervals (CI) calculated using Random Effects Model. Results: Sixteen studies were included involving; 616 MS patients and 655 healthy controls. 14 of these had acceptable or better quality but there was high heterogeneity. No difference was found between MS, healthy controls for folate and cobalamin concentrations; WMD 0.00ug/L (95% CI: -0.01, 0.01) and WMD 7.01pmol/L (95% CI: -25.54, 39.55) respectively. MS group showed mild-to-moderate disability WMD was 2.78 (95% CI: 2.00, 3.56). MS may be associated with elevated plasma homocysteine concentrations on average 2.47µmol/L more than healthy controls. Discussion: Physical ability of MS group was worse than healthy controls, but there was no difference in folate and cobalamin concentrations. This suggests folate and cobalamin are not influential factors in worsening physical function. There may be an association between worse cognitive function, and increased homocysteine concentrations. Results were inconclusive due to high heterogeneity and limited number of studies. A core outcome set would enable easier synthesis of future results.

Assessing Neurofilaments as Biomarkers of Neuroprotection in Progressive Multiple Sclerosis: From the MS-STAT Randomized Controlled Trial

Background and Objectives

Improved biomarkers of neuroprotective treatment are needed in progressive multiple sclerosis (PMS) to facilitate more efficient phase 2 trial design. The MS-STAT randomized controlled trial supported the neuroprotective potential of high-dose simvastatin in secondary progressive MS (SPMS). Here, we analyze serum from the MS-STAT trial to assess the extent to which neurofilament light (NfL) and neurofilament heavy (NfH), both promising biomarkers of neuroaxonal injury, may act as biomarkers of simvastatin treatment in SPMS.

Methods

The MS-STAT trial randomized patients to 80 mg simvastatin or placebo. Serum was analyzed for NfL and NfH using Simoa technology. We used linear mixed models to investigate the treatment effects of simvastatin compared with placebo on NfL and NfH. Additional models examined the relationships between neurofilaments and MRI and clinical measures of disease severity.

Results

A total of 140 patients with SPMS were included. There was no evidence for a simvastatin treatment effect on NfL or NfH: compared with placebo, NfL was 1.2% lower (95% CI 10.6% lower to 9.2% higher; p = 0.820) and NfH was 0.4% lower (95% CI 18.4% lower to 21.6% higher; p = 0.969) in the simvastatin treatment group. Secondary analyses suggested that higher NfL was associated with greater subsequent whole brain atrophy, higher T2 lesion volume, and more new/enlarging T2 lesions in the previous 12 months, as well as greater physical disability. There were no significant associations between NfH and MRI or clinical variables.

Discussion

We found no evidence of a simvastatin treatment effect on serum neurofilaments. While confirmation of the neuroprotective benefits of simvastatin is awaited from the ongoing phase 3 study (NCT03387670), our results suggest that treatments capable of slowing the rate of whole brain atrophy in SPMS, such as simvastatin, may act via mechanisms largely independent of neuroaxonal injury, as quantified by NfL. This has important implications for the design of future phase 2 clinical trials in PMS.

Trial Registration Information

MS-STAT: NCT00647348.

Classification of Evidence

This study provides class I evidence that simvastatin treatment does not have a large impact on either serum NfL or NfH, as quantified in this study, in SPMS.

Central nervous system macrophages in progressive multiple sclerosis: relationship to neurodegeneration and therapeutics

There are over 15 disease-modifying drugs that have been approved over the last 20 years for the treatment of relapsing–remitting multiple sclerosis (MS), but there are limited treatment options available for progressive MS. The development of new drugs for the treatment of progressive MS remains challenging as the pathophysiology of progressive MS is poorly understood.

The progressive phase of MS is dominated by neurodegeneration and a heightened innate immune response with trapped immune cells behind a closed blood–brain barrier in the central nervous system. Here we review microglia and border-associated macrophages, which include perivascular, meningeal, and choroid plexus macrophages, during the progressive phase of MS. These cells are vital and are largely the basis to define lesion types in MS. We will review the evidence that reactive microglia and macrophages upregulate pro-inflammatory genes and downregulate homeostatic genes, that may promote neurodegeneration in progressive MS. We will also review the factors that regulate microglia and macrophage function during progressive MS, as well as potential toxic functions of these cells. Disease-modifying drugs that solely target microglia and macrophage in progressive MS are lacking. The recent treatment successes for progressive MS include include B-cell depletion therapies and sphingosine-1-phosphate receptor modulators. We will describe several therapies being evaluated as a potential treatment option for progressive MS, such as immunomodulatory therapies that can target myeloid cells or as a potential neuroprotective agent.

Regulatory Mechanism of lncRNAs in M1/M2 Macrophages Polarization in the Diseases of Different Etiology

Precise expression and regulation of genes in the immune system is important for organisms to produce strong immunity towards pathogens and limit autoimmunity. In recent years, an increasing number of studies has shown that long noncoding RNAs (lncRNAs) are closely related to immune function and can participate in regulating immune responses by regulating immune cell differentiation, development, and function. As immune cells, the polarization response of macrophages (Mφs) plays an important role in immune function and inflammation. LncRNAs can regulate the phenotypic polarization of Mφs to M1 or M2 through various mechanisms; promote pro-inflammatory or anti-inflammatory effects; and participate in the pathogenesis of cancers, inflammatory diseases, infections, metabolic diseases, and autoimmune diseases. In addition, it is important to explore the regulatory mechanisms of lncRNAs on the dynamic transition between different Mφs phenotypes. Thus, the regulatory role of lncRNAs in the polarization of Mφs and their mechanism are discussed in this review.

Cerebrospinal Fluid α-Calcitonin Gene-Related Peptide: A Comparison between Alzheimer’s Disease and Multiple Sclerosis

Alzheimer’s disease (AD) and Multiple Sclerosis (MS) represent an emerging health problem on a global scale, as they are responsible for a significant contribution to the burden of disability in Western countries. Limited numbers of cerebrospinal fluid (CSF) diagnostic markers are available for each disease (amyloid and tau deposition markers for AD and oligoclonal bands for MS) representing mostly state markers that provide few, if any, clues about the severity of the clinical phenotype. α-CGRP is a neuropeptide implied in nociception, vasodilation, synaptic plasticity and immune functions. This neuropeptide is expressed in encephalic regions connected to memory, attention, autonomic and behavioral functions and is also expressed by spinal motor neurons. The present work confronted α-CGRP levels between 19 AD, 27 MS and 17 control subjects using an ELISA/EIA assay. We measured higher CSF α-CGRP contents in control subjects with respect to AD, as shown in previous studies, as well as in MS patients in comparison to AD. The control subjects and MS patients did not significantly differ between each other. We did not observe a relationship between CSF protein content, albumin quotient and α-CGRP. We also describe, retrospectively, an association between higher CSF CGRP content and higher MRI overall lesion count in MS and between lower α-CGRP and worse attention and visuo-perceptual skills in AD. We speculate that α-CGRP could be differentially involved in both disabling diseases.

Exosomes derived from bone marrow mesenchymal stromal cells promote remyelination and reduce neuroinflammation in the demyelinating central nervous system

Injury of oligodendrocytes (OLs) induces demyelination, and patients with neurodegenerative diseases exhibit demyelination concomitantly with neurological deficit and cognitive impairment. Oligodendrocyte progenitor cells (OPCs) are present in the adult central nervous system (CNS), and they can proliferate, differentiate, and remyelinate axons after damage. However, remyelination therapies are not in clinical use. Multiple sclerosis (MS) is a major demyelinating disease in the CNS. Mesenchymal stromal cells (MSCs) have demonstrated therapeutic promise in animal models and in clinical trials of MS. Exosomes are nanoparticles generated by nearly all cells and they mediate cell-cell communication by transferring cargo biomaterials. Here, we hypothesize that exosomes harvested from MSCs have a similar therapeutic effect on enhancement of remyelination as that of MSCs. In the present study we employed exosomes derived from rhesus monkey MSCs (MSC-Exo). Two mouse models of demyelination were employed: 1) experimental autoimmune encephalomyelitis (EAE), an animal model of MS; and 2) cuprizone (CPZ) diet model, a toxic demyelination model. MSC-Exo or PBS were intravenously injected twice a week for 4 weeks, starting on day 10 post immunization in EAE mice, or once a week for 2 weeks starting on the day of CPZ diet withdrawal. Neurological and cognitive function were tested, OPC differentiation and remyelination, neuroinflammation and the potential underlying mechanisms were investigated using immunofluorescent staining, transmission electron microscopy and Western blot. Data generated from the EAE model revealed that MSC-Exo cross the blood brain barrier (BBB) and target neural cells. Compared with the controls (p < 0.05), treatment with MSC-Exo: 1) significantly improved neurological outcome; 2) significantly increased the numbers of newly generated OLs (BrdU+/APC+) and mature OLs (APC+), and the level of myelin basic protein (MBP); 3) decreased amyloid-β precursor protein (APP)+ density; 4) decreased neuroinflammation by increasing the M2 phenotype and decreasing the M1 phenotype of microglia, as well as their related cytokines; 5) inhibited the TLR2/IRAK1/NFκB pathway. Furthermore, we confirmed that the MSC-Exo treatment significantly improved cognitive function, promoted remyelination, increased polarization of M2 phenotype and blocked TLR2 signaling in the CPZ model. Collectively, MSC-Exo treatment promotes remyelination by both directly acting on OPCs and indirectly by acting on microglia in the demyelinating CNS. This study provides the cellular and molecular basis for this cell-free exosome therapy on remyelination and modulation of neuroinflammation in the CNS, with great potential for treatment of demyelinating and neurodegenerative disorders.

Colony-stimulating factor-1 receptor inhibition attenuates microgliosis and myelin loss but exacerbates neurodegeneration in the chronic cuprizone model

Multiple sclerosis (MS), especially in its progressive phase, involves early axonal and neuronal damage resulting from a combination of inflammatory mediators, demyelination, and loss of trophic support. During progressive disease stages, a microenvironment is created within the central nervous system (CNS) favoring the arrival and retention of inflammatory cells. Active demyelination and neurodegeneration have also been linked to microglia (MG) and astrocyte (AST)-activation in early lesions. While reactive MG can damage tissue, exacerbate deleterious effects, and contribute to neurodegeneration, it should be noted that activated MG possess neuroprotective functions as well, including debris phagocytosis and growth factor secretion. The progressive form of MS can be modelled by the prolonged administration to cuprizone (CPZ) in adult mice, as CPZ induces highly reproducible demyelination of different brain regions through oligodendrocyte (OLG) apoptosis, accompanied by MG and AST activation and axonal damage. Therefore, our goal was to evaluate the effects of a reduction in microglial activation through orally administered brain-penetrant colony-stimulating factor-1 receptor (CSF-1R) inhibitor BLZ945 (BLZ) on neurodegeneration and its correlation with demyelination, astroglial activation and behavior in a chronic CPZ-induced demyelination model. Our results show that BLZ treatment successfully reduced the microglial population and myelin loss. However, no correlation was found between myelin preservation and neurodegeneration, as axonal degeneration was more prominent upon BLZ treatment. Concomitantly, BLZ failed to significantly offset CPZ-induced astroglial activation and behavioral alterations. These results should be taken into account when proposing the modulation of microglial activation in the design of therapies relevant for demyelinating diseases.

NAD+ improved experimental autoimmune encephalomyelitis by regulating SIRT1 to inhibit PI3K/Akt/mTOR signaling pathway

OBJECTIVE

To investigate the effect of NAD+ on thymus autophagy in experimental autoimmune encephalomyelitis (EAE) mice through SIRT1.

METHODS

Bioinformatic analysis was used to identify hub genes. Forty female C57BL/6 mice were randomly divided into 4 groups: control, EAE, NAD+, and NAD+ +SIRT1 inhibitor (SIRT-IN-3) groups and SIRT1 group. The NAD+ group and SIRT1 inhibitor group were treated with NAD+ drug and fed for 4 weeks. The neurological function scores were evaluated weekly. The thymus tissues of wild-type mice were removed, ground and filtered into single-cell suspension. MOG 35-55 (1 μg/mL) was given to primary thymic epithelial cells (TECs) to induce EAE model in vitro. The expression of LC-3A/B was observed by immunofluorescence. The expressions or the activation/phosphorylation of associated proteins were detected by Western blot.

RESULTS

Enrichment analysis showed PI3K-Akt-mTOR and autophagy pathway were main terms in EAE diseases, and the relationship between NAD+ and SIRT1. The activation of p-PI3K, p-Akt and p-mTOR were the highest in the EAE group consistent with decreased P62, Beclin1, LC-3A/B and SIRT1, and NAD+ reversed these results, furthermore SIRT1 inhibitor: SIRT-IN3 weakened the NAD+' effects in both in vivo and in vitro experiments. Immunofluorescence study in vivo and in vitro were accord with the results of western blot.

CONCLUSIONS

NAD+ exerted a protective effect on EAE mice by inhibiting PI3K/Akt/mTOR signaling pathway through SIRT1 in TECs, and prevented EAE mice from sustained damage.

Serum and Saliva Myelin Basic Protein as Multiple Sclerosis Biomarker

Introduction:

Multiple Sclerosis (MS) is presented with motor and sensory function loss. It is caused by demyelination and following axonal lesion. As Myelin Basic Protein (MBP) is one of the key elements of the myelin cover, we examined the level of MBP in serum, stimulated, and unstimulated saliva as a suitable biomarker for detecting MS.

Methods:

A case-control study was performed in 29 healthy women and 32 definitive relapsing-remitting MS patients hospitalized in Imam Reza hospital, Tehran, Iran. MBP level was assayed in serum and stimulated and unstimulated whole saliva.

Results:

MBP was expressed at a lower level in serum and stimulated saliva of MS patients compared to the control group. The serum MBP level had a considerable correlation with its stimulated saliva level. The receiver operating characteristic analysis showed significant diagnostic ability for MBP to discriminate MS patients with serum and stimulated saliva from controls.

Conclusion:

Serum and saliva level of MBP is lower in MS, so it may be considered a potential biomarker in MS.

Neuroimaging predictors of longitudinal disability and cognition outcomes in multiple sclerosis patients: A systematic review and meta-analysis

BACKGROUND

Cross-sectional magnetic resonance imaging (MRI) studies have generated substantial evidence relating neuroimaging abnormalities to clinical and cognitive decline in multiple sclerosis (MS). Longitudinal neuroimaging studies may have additional value for predicting future cognitive deficits or clinical impairment, potentially leading to earlier interventions and better disease management. We conducted a meta-analysis of longitudinal studies using neuroimaging to predict cognitive decline (i.e. the Symbol Digits Modalities Test, SDMT) and disability outcomes (i.e. the Expanded Disability Status Scale, EDSS) in MS.

METHODS

Our systematic literature search yielded 64 relevant publications encompassing 105 distinct sub-analyses. We performed a multilevel random-effects meta-analysis to estimate overall effect size for neuroimaging's ability to predict longitudinal cognitive and clinical decline, and a meta-regression to investigate the impact of distinct study factors on pooled effect size.

RESULTS

In the EDSS analyses, the meta-analysis yielded a medium overall pooled effect size (Pearson's correlation coefficient r = 0.42, 95% CI [0.37; 0.46]). The meta-regression further indicated that analyses exclusively evaluating gray matter tissue had significantly stronger effect sizes than analyses of white matter tissue or whole brain analyses (p < 0.05). No other study factors significantly influenced the pooled effect size (all p > 0.05). In the SDMT analyses, the meta-analysis yielded a medium overall pooled effect size (r = 0.47, 95% CI [0.32; 0.60]). The meta-regression found no significant study factors influencing the pooled effect size.

CONCLUSION

The present findings indicate that brain imaging is a medium predictor of longitudinal change in both disability progression (EDSS) and cognitive decline (SDMT). These findings reinforce the need for further longitudinal studies standardizing methods, using multimodal approaches, creating data consortiums, and publishing more complete datasets investigating MRI modalities to predict longitudinal disability and cognitive decline.