Secondary Progressive Multiple Sclerosis: New Insights

Cognitive Imapirment in Multiple Sclerosis: Relation to Dysability, Duration and Type of Disease

Background

Cognitive dysfunctions are often presented as a symptom in multiple sclerosis which is associated with both structural and functional imapirments of neuronal networks in the brain.

Objective

The aim of the study was to evaluate the influence of dysability, duration and type of disesase on cognitive functions in multiple sclerosis patients.

Methods

This study included 60 MS patients treated at the Department of Neurology, Clinical Center University of Sarajevo. Inclusion criteria were clinically definite diagnosis of multiple sclerosis, 18 years of age or older and were able to give written informed consent. Cognitive function was evaluated by the Montreal Cognitive Assessment (MoCa) screening test. Mann-Whitney and Kruskal-Wallis test were used for comparisons between clinical characteristics and MoCa test scores.

Results

Out of 63.33% of patients had EDSS <=4.5. Disease lasted longer than 10 years in 30% of patients. 80% had relapsing-remitting MS and 20% had secondary progressive MS. 84,2 % of patients with EDSS ≤ 4.5 had cognitive dysfunction. Higher disability (rho=0,306, p<0,05), progressive type of disease (rho=0,377, p< 0,01) and longer disease duration (rho=0,282, p<0,05) were associated with worse overall cognitive functions. Level of disability showed statistical significant correlation with the executive functions and language domains of cognition (p<0.01). Longer disease duration was significant correlated with executive functions (p<0,01) and language domains (p<0,01), while progressive type of disease was signifacant correlated only with executive functions domain (p<0,01). MoCa score variables did not show a statistically significant difference in relation to the number of relapses per year and the use of imunoterapy. Statistically significant negative correlation was obtained between executive functions domain and level of disability, disease duration and progressive type of disease, while language domain significantly correlated only with disability level and progressive type of disease.

Conclusion

High percentage of MS patients has cognitive impairment. Patients with higher disability were presented with lower cognitive abilities, especially in executive functions and language domains. Higher frequency of cognitive impairment were presented in progessive forms of disaese and longer disease duration with strong influence on executive functions domains of cognition.

Recent Progress in the Identification of Early Transition Biomarkers from Relapsing-Remitting to Progressive Multiple Sclerosis

Despite extensive research into the pathophysiology of multiple sclerosis (MS) and recent developments in potent disease-modifying therapies (DMTs), two-thirds of relapsing-remitting MS patients transition to progressive MS (PMS). The main pathogenic mechanism in PMS is represented not by inflammation but by neurodegeneration, which leads to irreversible neurological disability. For this reason, this transition represents a critical factor for the long-term prognosis. Currently, the diagnosis of PMS can only be established retrospectively based on the progressive worsening of the disability over a period of at least 6 months. In some cases, the diagnosis of PMS is delayed for up to 3 years. With the approval of highly effective DMTs, some with proven effects on neurodegeneration, there is an urgent need for reliable biomarkers to identify this transition phase early and to select patients at a high risk of conversion to PMS. The purpose of this review is to discuss the progress made in the last decade in an attempt to find such a biomarker in the molecular field (serum and cerebrospinal fluid) between the magnetic resonance imaging parameters and optical coherence tomography measures.

Proportion and characteristics of secondary progressive multiple sclerosis in five European registries using objective classifiers

Background

To assign a course of secondary progressive multiple sclerosis (MS) (SPMS) may be difficult and the proportion of persons with SPMS varies between reports. An objective method for disease course classification may give a better estimation of the relative proportions of relapsing-remitting MS (RRMS) and SPMS and may identify situations where SPMS is under reported.

Materials and methods

Data were obtained for 61,900 MS patients from MS registries in the Czech Republic, Denmark, Germany, Sweden, and the United Kingdom (UK), including date of birth, sex, SP conversion year, visits with an Expanded Disability Status Scale (EDSS) score, MS onset and diagnosis date, relapses, and disease-modifying treatment (DMT) use. We included RRMS or SPMS patients with at least one visit between January 2017 and December 2019 if ≥ 18 years of age. We applied three objective methods: A set of SPMS clinical trial inclusion criteria ("EXPAND criteria") modified for a real-world evidence setting, a modified version of the MSBase algorithm, and a decision tree-based algorithm recently published.

Results

The clinically assigned proportion of SPMS varied from 8.7% (Czechia) to 34.3% (UK). Objective classifiers estimated the proportion of SPMS from 15.1% (Germany by the EXPAND criteria) to 58.0% (UK by the decision tree method). Due to different requirements of number of EDSS scores, classifiers varied in the proportion they were able to classify; from 18% (UK by the MSBase algorithm) to 100% (the decision tree algorithm for all registries). Objectively classified SPMS patients were older, converted to SPMS later, had higher EDSS at index date and higher EDSS at conversion. More objectively classified SPMS were on DMTs compared to the clinically assigned.

Conclusion

SPMS appears to be systematically underdiagnosed in MS registries. Reclassified patients were more commonly on DMTs.

Distinctive transcriptomic and epigenomic signatures of bone marrow-derived myeloid cells and microglia in CNS autoimmunity

In the context of autoimmunity, myeloid cells of the central nervous system (CNS) constitute an ontogenically heterogeneous population that includes yolk sac-derived microglia and infiltrating bone marrow-derived cells (BMC). We previously identified a myeloid cell subset in the brain and spinal cord that expresses the surface markers CD88 and CD317 and is associated with the onset and persistence of clinical disease in the murine model of the human CNS autoimmune disorder, experimental autoimmune encephalomyelitis (EAE). We employed an experimental platform utilizing single-cell transcriptomic and epigenomic profiling of bone marrow-chimeric mice to categorically distinguish BMC from microglia during CNS autoimmunity. Analysis of gene expression and chromosomal accessibility identified CD88+CD317+ myeloid cells in the CNS of EAE mice as originating from BMC and microglia. Interestingly, each cell lineage exhibited overlapping and unique gene expression patterns and transcription factor motifs that allowed their segregation. Our observations will facilitate determining pathogenic contributions of BMC and microglia in CNS autoimmune disease. Ultimately, this agnostic characterization of myeloid cells will be required for devising disease stage-specific and tissue-specific interventions for CNS inflammatory and neurodegenerative disorders.

The uncertainty period preceding the clinical defined SPMS diagnosis and the applicability of objective classifiers - A Danish single center study

BACKGROUND

The clinical transition from relapsing-remitting multiple sclerosis (RRMS) to secondary progressive MS (SPMS) is often related to a period of diagnostic uncertainty delaying diagnosis. With emerging treatment options for SPMS how to identify RRMS patients at risk of SPMS and when to assign a SPMS diagnosis has become a matter of growing clinical concern. This study aimed to determine the period of diagnostic uncertainty among Danish MS patients. Secondly, this study examined the performance of two objective classifiers in a longitudinal setting regarding their ability to shorten the period of diagnostic uncertainty.

METHODS

By using the Danish Multiple Sclerosis Registry, we identified all patients linked to Rigshospitalet with clinically assigned SPMS from 2010 to 2021. We reviewed all patient records and identified the first mentioned sign of progression (FMP). The time between the dates of FMP and clinically assigned SPMS was defined as the period of diagnostic uncertainty. Secondly, we applied two objective classifiers (the Karolinska Decision tree and the MSBase criteria) to generate suggested transition dates and compared them to the ones obtain from the patient records. Detailed descriptions of the population were made at all mentioned timepoints.

RESULTS

In total 138 patients were included. We found a median period of diagnostic uncertainty of 2.12 years. The objective classifiers generated a median suggested transition date 3.44 and 4.48 years earlier than the date of clinically assigned SPMS, but they only provided an earlier SPMS transition date in 50.72% and 55.80% of cases.

CONCLUSIONS

Our findings emphasize the uncertainty related to the transition from RRMS to SPMS illustrating the need of an improved diagnostic approach. Objective classifiers might have the potential to help reduce the period of diagnostic uncertainty in the future, but in their current form they do not perform satisfactorily enough to solve all difficulties related to detecting SPMS-transition.

Disease-modifying therapies for relapsing/active secondary progressive multiple sclerosis - a review of population-specific evidence from randomized clinical trials

Although the understanding of secondary progressive multiple sclerosis (SPMS) is evolving, early detection of relapse-independent progression remains difficult. This is further complicated by superimposed relapses and compensatory mechanisms that allow for silent progression. The term relapsing multiple sclerosis (RMS) subsumes relapsing-remitting multiple sclerosis (RRMS) and SPMS with relapses. The latter is termed 'active' SPMS, for which disease-modifying therapies (DMTs) approved for either RMS or active SPMS can be used. However, the level of evidence supporting efficacy and safety in SPMS differs between drugs approved for RMS and SPMS. Our review aims to identify current evidence from published clinical trials and European public assessment reports from the marketing authorization procedure on the efficacy, especially on progression, of DMTs approved for RMS and SPMS. To identify relevant evidence, a literature search has been conducted and European public assessment reports of DMTs approved for RMS have been screened for unpublished data specific to SPMS. Only two clinical trials demonstrated a significant reduction in disability progression in SPMS study populations: the EXPAND study for siponimod, which included a typical SPMS population, and the European study for interferon (IFN)-beta 1b s.c., which included patients with very early and active SPMS. Both DMTs also achieved significant reductions in relapse rates. Ocrelizumab, cladribine, ofatumumab, and ponesimod are all approved for RMS - ocrelizumab, ofatumumab, and ponesimod based on an RMS study, cladribine based on an RRMS study. Data on efficacy in SPMS are only available from post hoc analyses of very small subgroups, representing only up to 15% of the total study population. For these DMTs, approval for RMS, including active SPMS, was mainly based on the assumption that the reduction in relapse rate observed in patients with RRMS can also be applied to SPMS. Based on that, the potential of these drugs to reduce relapse-independent progression remains unclear.

Current understanding of the cGAS-STING signaling pathway: Structure, regulatory mechanisms, and related diseases

The innate immune system protects the host from external pathogens and internal damage in various ways. The cGAS-STING signaling pathway, comprised of cyclic GMP-AMP synthase (cGAS), stimulator of interferon genes (STING), and downstream signaling adaptors, plays an essential role in protective immune defense against microbial DNA and internal damaged-associated DNA and is responsible for various immune-related diseases. After binding with DNA, cytosolic cGAS undergoes conformational change and DNA-linked liquid-liquid phase separation to produce 2'3'-cGAMP for the activation of endoplasmic reticulum (ER)-localized STING. However, further studies revealed that cGAS is predominantly expressed in the nucleus and strictly tethered to chromatin to prevent binding with nuclear DNA, and functions differently from cytosolic-localized cGAS. Detailed delineation of this pathway, including its structure, signaling, and regulatory mechanisms, is of great significance to fully understand the diversity of cGAS-STING activation and signaling and will be of benefit for the treatment of inflammatory diseases and cancer. Here, we review recent progress on the above-mentioned perspectives of the cGAS-STING signaling pathway and discuss new avenues for further study.

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.

Serum neurofilament light chains in progressive multiple sclerosis patients treated with repeated cycles of high-dose intravenous steroids

Background and objectives: In progressive multiple sclerosis (MS) patients, CNS inflammation trapped behind a closed blood brain barrier drives continuous neuroaxonal degeneration, thus leading to deterioration of neurological function. Therapeutics in progressive MS are limited. High-dose intravenous glucocorticosteroids (HDCS) can cross the blood-brain barrier and may reduce inflammation within the CNS. However, the treatment efficacy of HDCS in progressive MS remains controversial. Serum neurofilament light chains (sNfL) are an established biomarker of neuroaxonal degeneration and are used to monitor treatment responses. We aimed to investigate whether repeated cycles of intravenous HDCS reduce the level of sNfL in progressive MS patients. Methods: We performed a monocentric observational study of 25 patients recruited during ongoing clinical routine care who were treated with repeated cycles of intravenous HDCS as long-term therapy for their progressive MS. sNfL were measured in 103 repeated blood samples (median time interval from baseline 28 weeks, range 2-55 weeks) with the Single Molecular Array (SiMoA) technology. The Expanded Disability Status Score (EDSS) was documented at baseline and follow-up. Results: The median age of patients was 55 years (range 46-77 years) with a median disease duration of 26 years (range 11-42 years). sNfL baseline levels at study inclusion were significantly higher in progressive MS patients compared to age-matched healthy controls (median 16.7 pg/ml vs 11.5 pg/ml, p=0.002). sNfL levels showed a positive correlation with patient age (r=0.2, p=0.003). The majority of patients (72%, 16/23) showed reduced sNfL levels ≥20 weeks after HDCS compared to baseline (median 13.3 pg/ml, p=0.03). sNfL levels correlated negatively with the time interval from baseline HDCS therapy (r=-0.2, p=0.03). This association was also evident after correction for treatment with disease-modifying drugs (adjusted R2=0.10, p=0.001). The EDSS remained stable (median 6.5) within a median treatment duration of 26 weeks (range 13-51 weeks). Conclusion: Although larger studies are needed to confirm our findings, we were able to demonstrate that HDCS treatment reduces sNfL levels and therefore may slow down neuroaxonal damage in a subgroup of patients with progressive MS. Moreover, a stable EDSS was observed during therapy. Findings suggest that HDCS may be beneficial for the treatment of progressive MS.

Serum GFAP and NfL Levels Differentiate Subsequent Progression and Disease Activity in Patients With Progressive Multiple Sclerosis

Background and Objectives

Neurodegeneration and astrocytic activation are pathologic hallmarks of progressive multiple sclerosis (MS) and can be quantified by serum neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP). We investigated sNfL and sGFAP as tools for stratifying patients with progressive MS based on progression and disease activity status.

Methods

We leveraged our Comprehensive Longitudinal Investigation of MS at the Brigham and Women's Hospital (CLIMB) natural history study, which includes clinical, MRI data and serum samples collected over more than 20 years. We included patients with MS with a confirmed Expanded Disability Status Scale (EDSS) score ≥3 that corresponds with our classifier for patients at high risk of underlying progressive pathology. We analyzed sNfL and sGFAP within 6 months from the confirmed EDSS score ≥3 corresponding with our baseline visit. Patients who further developed 6-month confirmed disability progression (6mCDP) were classified as progressors. We further stratified our patients into active/nonactive based on new brain/spinal cord lesions or relapses in the 2 years before baseline or during follow-up. Statistical analysis on log-transformed sGFAP/sNfL assessed the baseline association with demographic, clinical, and MRI features and associations with future disability.

Results

We included 257 patients with MS who had an average EDSS score of 4.0 and a median follow-up after baseline of 7.6 years. sNfL was higher in patients with disease activity in the 2 years before baseline (adjusted β = 1.21; 95% CI 1.04–1.42;p= 0.016), during the first 2 years of follow-up (adjusted β = 1.17; 95% CI = 1.01–1.36;p= 0.042). sGFAP was not increased in the presence of disease activity. Higher sGFAP levels, but not sNfL levels, were associated with higher risk of 6mCDP (adjusted hazard ratio [HR] = 1.71; 95% CI = 1.19–2.45;p= 0.004). The association was stronger in patients with low sNfL (adjusted HR = 2.44; 95% CI 1.32–4.52;p= 0.005) and patients who were nonactive in the 2 years prior or after the sample.

Discussion

Higher levels of sGFAP correlated with subsequent progression, particularly in nonactive patients, whereas sNfL reflected acute disease activity in patients with MS at high risk of underlying progressive pathology. Thus, sGFAP and sNfL levels may be used to stratify patients with progressive MS for clinical research studies and clinical trials and may inform clinical care.

Health economic outcomes of switching to alemtuzumab from other disease-modifying therapies in people with multiple sclerosis in the USA

Aim: Describe demographics, clinical characteristics, healthcare resource utilization (HCRU) and costs in people with multiple sclerosis (pwMS) switching to alemtuzumab from other disease-modifying therapies (DMTs). Patients & methods: Retrospective, observational study of IBM®MarketScan® claims database. PwMS previously treated with DMTs and initiating alemtuzumab (1 January 2013 to 31 December 2019) were identified. "Index" was date of alemtuzumab initiation (prescription filled). Results: The study cohort (n = 341) was primarily female (72%) with (mean ± standard deviation) age 45.1 ± 9.5 years. At index, duration of MS was 5.3 ± 2.8 years. HCRU (inpatient/outpatient services), outpatient costs (including MS-specific MRI and emergency room visits) and annualized relapse rate significantly reduced over the 2 years following initiation of alemtuzumab. DMT costs reduced over the same period. Conclusion: Health economic and clinical benefits were seen following switching to alemtuzumab from other DMTs for treatment of MS, in this cohort from the USA.

In Silico Structural Analysis Predicting the Pathogenicity of PLP1 Mutations in Multiple Sclerosis

The X chromosome gene PLP1 encodes myelin proteolipid protein (PLP), the most prevalent protein in the myelin sheath surrounding the central nervous system. X-linked dysmyelinating disorders such as Pelizaeus-Merzbacher disease (PMD) or spastic paraplegia type 2 (SPG2) are typically caused by point mutations in PLP1. Nevertheless, numerous case reports have shown individuals with PLP1 missense point mutations which also presented clinical symptoms and indications that were consistent with the diagnostic criteria of multiple sclerosis (MS), a disabling disease of the brain and spinal cord with no current cure. Computational structural biology methods were used to assess the impact of these mutations on the stability and flexibility of PLP structure in order to determine the role of PLP1 mutations in MS pathogenicity. The analysis showed that most of the variants can alter the functionality of the protein structure such as R137W variants which results in loss of helix and H140Y which alters the ordered protein interface. In silico genomic methods were also performed to predict the significance of these mutations associated with impairments in protein functionality and could suggest a better definition for therapeutic strategies and clinical application in MS patients.

Remyelination in Multiple Sclerosis: Findings in the Cuprizone Model

Remyelination therapies, which are currently under development, have a great potential to delay, prevent or even reverse disability in multiple sclerosis patients. Several models are available to study the effectiveness of novel compounds in vivo, among which is the cuprizone model. This model is characterized by toxin-induced demyelination, followed by endogenous remyelination after cessation of the intoxication. Due to its high reproducibility and ease of use, this model enjoys high popularity among various research and industrial groups. In this review article, we will summarize recent findings using this model and discuss the potential of some of the identified compounds to promote remyelination in multiple sclerosis patients.

Self-assessment of people with relapsing-remitting and progressive multiple sclerosis towards burden of disease, progression, and treatment utilization-Results of a large-scale cross-sectional online survey (MS Perspectives)

BACKGROUND

Assessment of the disease course by people with multiple sclerosis (pwMS) themselves is important for a better understanding of the complex disease, patient counseling and treatment decisions. This may also facilitate identifying the often-unnoticed transition from relapsing-remitting (RRMS) to secondary progressive multiple sclerosis (SPMS).

OBJECTIVE

MS Perspectives was designed to collect data on patients' self-assessment of multiple sclerosis (MS) symptoms, relapse-independent progression, and impact on everyday life.

METHODS

MS Perspectives is a cross-sectional online survey conducted among adult pwMS in Germany. The questionnaire included 36 items on sociodemographic and clinical characteristics as well as pharmacological and non-pharmacological treatment.

RESULTS

In total, 4555 pwMS completed the survey between December 2021 and February 2022, 69.2% had RRMS, 15.1% had SPMS. Relapse-independent worsening of symptoms was reported by 88.9% of RRMS patients with marked to severe and by 61.8% with no or mild to moderate disability. Problems with walking were most frequently (32.1%) mentioned as most bothersome by RRMS patients with marked to severe disability, fatigue, and cognitive impairment by RRMS patients with no or mild to moderate disability.

CONCLUSION

MS Perspectives gives an important insight in the self-assessed disease course and impact on daily life in a large-scale cohort of pwMS.

Efficacy, safety and patient reported outcomes in patients with active relapsing multiple sclerosis treated with ocrelizumab: Final results from the PRO-MSACTIVE study

BACKGROUND

Ocrelizumab, a humanized anti-CD20 monoclonal antibody, has been approved in Europe for the treatment of adult patients with active relapsing multiple sclerosis (RMS) and primary progressive multiple sclerosis (PPMS), on the basis of previous phase III studies. However, limited data were available on ocrelizumab efficacy in RMS according to the Lublin definition of activity (clinical and/or imaging features) used in the current drug label. The PRO-MSACTIVE study was thus designed to provide additional data on ocrelizumab efficacy according to this definition, and also on safety and patient reported outcomes (PROs).

METHODS

PRO-MSACTIVE is a national, multicenter, open-label, single-arm phase IV French study, conducted in patients with active RMS (relapsing-remitting multiple sclerosis, RRMS, or secondary progressive multiple sclerosis, SPMS). The primary endpoint, which was assessed at week (W) 48, was defined as the proportion of patients free of disease activity (defined by no relapses and no T1 gadolinium-enhancing nor new and/or enlarging T2 lesions using brain MRI). Disease activity, disability and PROs using 6 questionnaires for disease severity, quality of life, impact on work productivity, and treatment satisfaction were described at W24 and W48. Adverse events were described until W72.

RESULTS

Among the 422 analyzed patients (RRMS: 376, SPMS: 46), 63.3% (95% CI [58.5%; 67.9%]) were free of disease activity at W48 (RRMS: 62.2% [57.1%; 67.2%], SPMS: 71.7% [56.5%; 84.0%]). A total of 358 patients (84.8%; RRMS: 84.6%, SPMS: 87.0%) were relapse-free up to W48, and the overall adjusted annualized relapse rate was 0.14 (RRMS: 0.15, SPMS: 0.09). Overall, 67.8% of patients (RRMS: 66.8%, SPMS: 76.1%) had no evidence of MRI activity (no T1 gadolinium-enhancing lesions [83.4%] and no new/enlarging T2 lesions [75.1%]); 58.5% of patients (RRMS: 57.7%, SPMS: 65.2%) achieved No Evidence of Disease Activity (NEDA: no relapses, no confirmed disability progression, and no MRI activity) at W48. All PRO scores were stable between the first dose of ocrelizumab and W48 and better outcomes were seen for patients having an EDSS score ≥4. Overall, 89.3% of patients reported adverse events, 62.3% adverse events assessed as related to ocrelizumab, and 8.5% serious adverse events. No serious infusion-related reactions, opportunistic infections, progressive multifocal leukoencephalopathy, nor deaths were reported. No new safety signal was identified.

CONCLUSION

These data confirm the efficacy of ocrelizumab in a pragmatic setting and its favorable benefit-risk profile in patients with RMS. (ClinicalTrials.gov identifier: NCT03589105; EudraCT identifier: 2018-000780-91).

Discussing the potential for progression with patients newly diagnosed with multiple sclerosis: When, how, and why?

Despite convergent evidence that upwards of 50% of patients with MS transition from a relapsing to progressive phase within 20 years of disease onset, and the recent acknowledgement of the commonality of progression independent of relapses, there remains no consensus regarding the nature and timing of a discussion about the possibility of a secondary progressive phase with relapsing-remitting MS patients. Some neurologists prefer to conduct this at the inaugural visit to provide more information about disease behaviour and potential planning that might entail, while others may defer any discussion about this phase, as there is no clear consensus for it and it can be a sensitive topic, with concern that too early a discussion could worsen anxiety and discourage or delay decisions regarding disease modifying treatments. Furthermore, it is unknown at onset which patients will transition to a progressive phenotype. This review and opinion paper will outline some of the opportunities and challenges associated with such a disclosure, and attempt to provide a balanced, patient-centred approach to address this delicate topic.

The Effects of Dietary Interventions on Brain Aging and Neurological Diseases

Dietary interventions can ameliorate age-related neurological decline. Decades of research of in vitro studies, animal models, and clinical trials support their ability and efficacy to improve behavioral outcomes by inducing biochemical and physiological changes that lead to a more resilient brain. Dietary interventions including calorie restriction, alternate day fasting, time restricted feeding, and fasting mimicking diets not only improve normal brain aging but also slow down, or even reverse, the progression of neurological diseases. In this review, we focus on the effects of intermittent and periodic fasting on improving phenotypic outcomes, such as cognitive and motor-coordination decline, in the normal aging brain through an increase in neurogenesis and synaptic plasticity, and decrease in neuroinflammation, mitochondrial dysfunction, and oxidative stress. We summarize the results of various dietary interventions in animal models of age-related neurological diseases such as Alzheimer's disease, Parkinson's disease, epilepsy, and Multiple Sclerosis and discuss the results of clinical trials that explore the feasibility of dietary interventions in the prevention and treatment of these diseases.

Probiotics and Commensal Gut Microbiota as the Effective Alternative Therapy for Multiple Sclerosis Patients Treatment

The gut-brain axis (GBA) refers to the multifactorial interactions between the intestine microflora and the nervous, immune, and endocrine systems, connecting brain activity and gut functions. Alterations of the GBA have been revealed in people with multiple sclerosis (MS), suggesting a potential role in disease pathogenesis and making it a promising therapeutic target. Whilst research in this field is still in its infancy, a number of studies revealed that MS patients are more likely to exhibit modified microbiota, altered levels of short-chain fatty acids, and enhanced intestinal permeability. Both clinical and preclinical trials in patients with MS and animal models revealed that the administration of probiotic bacteria might improve cognitive, motor, and mental behaviors by modulation of GBA molecular pathways. According to the newest data, supplementation with probiotics may be associated with slower disability progression, reduced depressive symptoms, and improvements in general health in patients with MS. Herein, we give an overview of how probiotics supplementation may have a beneficial effect on the course of MS and its animal model. Hence, interference with the composition of the MS patient's intestinal microbiota may, in the future, be a grip point for the development of diagnostic tools and personalized microbiota-based adjuvant therapy.

Impact of Siponimod on Enteric and Central Nervous System Pathology in Late-Stage Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS). Although immune modulation and suppression are effective during relapsing-remitting MS, secondary progressive MS (SPMS) requires neuroregenerative therapeutic options that act on the CNS. The sphingosine-1-phosphate receptor modulator siponimod is the only approved drug for SPMS. In the pivotal trial, siponimod reduced disease progression and brain atrophy compared with placebo. The enteric nervous system (ENS) was recently identified as an additional autoimmune target in MS. We investigated the effects of siponimod on the ENS and CNS in the experimental autoimmune encephalomyelitis model of MS. Mice with late-stage disease were treated with siponimod, fingolimod, or sham. The clinical disease was monitored daily, and treatment success was verified using mass spectrometry and flow cytometry, which revealed peripheral lymphopenia in siponimod- and fingolimod-treated mice. We evaluated the mRNA expression, ultrastructure, and histopathology of the ENS and CNS. Single-cell RNA sequencing revealed an upregulation of proinflammatory genes in spinal cord astrocytes and ependymal cells in siponimod-treated mice. However, differences in CNS and ENS histopathology and ultrastructural pathology between the treatment groups were absent. Thus, our data suggest that siponimod and fingolimod act on the peripheral immune system and do not have pronounced direct neuroprotective effects.

Total astragalosides promote oligodendrocyte precursor cell differentiation and enhance remyelination in cuprizone-induced mice through suppression of Wnt/β-catenin signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Radix Astragali is a traditional Chinese medicine with various pharmacological effects. Total astragalosides (TA), the main effective ingredients in Radix Astragali, exert properties including anti-oxidative stress, anti-neuroinflammation, and neuroprotection. We previously found that TA alleviated experimental autoimmune encephalomyelitis (EAE) progression, a widely used animal model of multiple sclerosis (MS). As a chronic demyelination disease, MS generally manifests myelin loss and fails to myelin regeneration. Regulation of oligodendrocyte progenitor cells (OPCs) differentiation and remyelination is the fundamental strategy for MS treatment. However, whether TA could directly promote OPCs differentiation and remyelination is still unknown.

AIMS OF THE STUDY

This study was aimed to investigate pro-differentiation and myelin regeneration effects of TA on OPCs and Cuprizone (CPZ)-induced demyelination mice, an animal model of MS, and to explore mechanism underlying from regulation of OPCs differentiation and maturation.

MATERIALS AND METHODS

Mice were orally given CPZ (400 mg/kg) daily for 4 weeks to induce myelin loss, and then treated with TA (25 and 50 mg/kg) daily for 1 week. Cell proliferation assay, Western blot, RT-PCR, immunocytochemistry and immunohistochemistry were performed to explore the mechanisms. The role of TA in oligodendrocyte differentiation and maturation was evaluated using MO3.13, a human oligodendrocytic hybrid cell line.

RESULTS

TA was shown to mitigate behavioral impairment in CPZ-induced mice. It markedly ameliorated myelin loss and enhanced remyelination in the corpus callosum of mice, evidenced by increased expression of myelin basic protein (MBP) and the number of CC1⁺ newly generated oligodendrocytes (OLs). TA also enhanced the expression of MBP at both mRNA and protein levels in MO3.13 cells. In CPZ-induced mice and MO3.13 cells, TA remarkably promoted the activation of GSK3β, repressed the phosphorylation of β-catenin, reduced the expression of transcription factor 4 and inhibitor of DNA binding 2. The agonist of β-catenin, SKL2001, partially abolished the pro-differentiation effect of TA in MO3.13 cells.

CONCLUSIONS

Taken together, we clarified that TA could effectively enhance the differentiation and maturation of OPCs and accelerate remyelination in CPZ-induced mice through inhibition of Wnt/β-catenin signaling pathway. This study provides new insight into the beneficial effect of TA in the treatment of MS.

Diroximel Fumarate as a Novel Oral Immunomodulating Therapy for Relapsing Forms of Multiple Sclerosis: A Review on the Emerging Data

Multiple sclerosis (MS) is a chronic inflammatory, demyelinating and neurodegenerative disorder of the central nervous system. Disease-modifying drugs (DMDs) and subsequent adherence are crucial for preventing reversible episodes of neurological dysfunction and delayed onset of progressive accumulation of irreversible deficits. Yet, side effects may limit their usage in clinical practice. Gastrointestinal (GI) side effects are a significant limitation of the use of dimethyl fumarate (DMF), the most frequently prescribed oral DMD in MS worldwide. Diroximel fumarate (DRF) is a second-generation oral fumaric acid ester (FAE) that was developed as a formulation with better GI tolerability. The improved tolerability is assumed to be related to a lower synthesis of gut-irritating methanol. Other explanations for DRF’s lower extent of GI irritation include a more modest off-target activity due to its chemical structure. The superior GI tolerability of DRF compared to DMF could be proven in clinical trials and lead to approval of DRF for the treatment of relapsing forms of MS/relapsing-remitting MS (United States Food and Drug Administration and European Medicines Agency, respectively). Here, we summarize the mode of action of oral FAE and compare the chemical and physiological characteristics of DMF and DRF. Moreover, we discuss the adverse effects of FAE and introduce the emerging preclinical and trial data leading to the approval of DRF in MS. This article additionally reviews our current understanding of coronavirus disease 2019 (COVID-19) and the efficacy of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccination in people treated with FAE.

Neurofilaments contribution in clinic: state of the art

Neurological biomarkers are particularly valuable to clinicians as they can be used for diagnosis, prognosis, or response to treatment. This field of neurology has evolved considerably in recent years with the improvement of analytical methods, allowing the detection of biomarkers not only in cerebrospinal fluid (CSF) but also in less invasive fluids like blood. These advances greatly facilitate the repeated quantification of biomarkers, including at asymptomatic stages of the disease. Among the various informative biomarkers of neurological disorders, neurofilaments (NfL) have proven to be of particular interest in many contexts, such as neurodegenerative diseases, traumatic brain injury, multiple sclerosis, stroke, and cancer. Here we discuss these different pathologies and the potential value of NfL assay in the management of these patients, both for diagnosis and prognosis. We also describe the added value of NfL compared to other biomarkers currently used to monitor the diseases described in this review.

Potential nanocarrier-mediated miRNA-based therapy approaches for multiple sclerosis

Multiple sclerosis (MS) is an autoimmune neuroinflammatory disorder attributed to neurodegeneration and demyelination, resulting in neurological impairment. miRNA has a significant role in biological processes in MS. In this review, we focus on the feasibility of delivering miRNAs through nanoformulations for managing MS. We provide a brief discussion of miRNA synthesis and evidence for miRNA dysregulation in MS. We also highlight formulation strategies and resulting technologies for the effective delivery of miRNAs through nanocarrier systems for achieving high therapeutic benefits.

Differences in Age-related Retinal and Cortical Atrophy Rates in Multiple Sclerosis

BACKGROUND AND OBJECTIVES

The timing of neurodegeneration in multiple sclerosis (MS) remains unclear. It is critical to understand the dynamics of neuroaxonal loss if we hope to prevent or forestall permanent disability in MS. We therefore used a deeply phenotyped longitudinal cohort to assess and compare rates of neurodegeneration in retina and brain throughout the MS disease course.

METHODS

We analyzed 597 patients with MS who underwent longitudinal optical coherence tomography imaging annually for 4.5 ± 2.4 years and 432 patients who underwent longitudinal MRI scans for 10 ± 3.4 years, quantifying macular ganglion cell-inner plexiform layer (GCIPL) volume and cortical gray matter (CGM) volume. The association between the slope of decline in the anatomical structure and the age of entry in the cohort (categorized by the MRI cohort's age quartiles) was assessed by hierarchical linear models.

RESULTS

The rate of CGM volume loss declined with increasing age of study entry (1.3% per year atrophy for the age of entry in the cohort younger than 35 years; 1.1% for older than 35 years and younger than 41; 0.97% for older than 41 years and younger than 49; 0.9% for older than 49 years) while the rate of GCIPL thinning was highest in patients in the youngest quartile, fell by more than 50% in the following age quartile, and then stabilized (0.7% per year thinning for the age of entry in the cohort younger than 35 years; 0.29% for age older than 35 and younger than 41 years; 0.34% for older than 41 and younger than 49 years; 0.33% for age older than 49 years).

DISCUSSION

An age-dependent reduction in retinal and cortical volume loss rates during relapsing-remitting MS suggests deceleration in neurodegeneration in the earlier period of disease and further indicates that the period of greatest adaptive immune-mediated inflammatory activity is also the period with the greatest neuroaxonal loss.

Motor Behavioral Deficits in the Cuprizone Model: Validity of the Rotarod Test Paradigm

Multiple Sclerosis (MS) is a neuroinflammatory disorder, which is histopathologically characterized by multifocal inflammatory demyelinating lesions affecting both the central nervous system’s white and grey matter. Especially during the progressive phases of the disease, immunomodulatory treatment strategies lose their effectiveness. To develop novel progressive MS treatment options, pre-clinical animal models are indispensable. Among the various different models, the cuprizone de- and remyelination model is frequently used. While most studies determine tissue damage and repair at the histological and ultrastructural level, functional readouts are less commonly applied. Among the various overt functional deficits, gait and coordination abnormalities are commonly observed in MS patients. Motor behavior is mediated by a complex neural network that originates in the cortex and terminates in the skeletal muscles. Several methods exist to determine gait abnormalities in small rodents, including the rotarod testing paradigm. In this review article, we provide an overview of the validity and characteristics of the rotarod test in cuprizone-intoxicated mice.

Real-World Assessment of Quality of Life in Patients with Relapsing Remitting Multiple Sclerosis Treated with Teriflunomide for Two Years: Patient-Reported Outcomes from the AURELIO Study in Greece

INTRODUCTION

Multiple sclerosis (MS) is a highly heterogeneous inflammatory disease of the central nervous system. Patient-reported outcomes (PROs) in a real-world clinical setting can provide detailed information about MS from the patient's perspective. PROs were used here to assess quality of life (QoL), treatment satisfaction, clinical efficacy, and safety outcomes in a Greek cohort of relapsing remitting MS (RRMS) patients treated with oral teriflunomide (14 mg/day).

METHODS

AURELIO was a 2-year, prospective, observational study whose QoL primary endpoint was assessed with the Multiple Sclerosis Impact Scale (MSIS-29). Secondary endpoints included analyses of Patient Determined Disease Steps (PDDS), Treatment Satisfaction Questionnaire for Medication (TSQM), Expanded Disability Status Scale (EDSS), annualized relapse rate (ARR), adherence, and safety outcomes.

RESULTS

AURELIO enrolled 282 patients (62.8% female; mean age 44.8 [SD ± 11] years; EDSS 2.0 [SD ± 1.6]; 44.6% treatment-naïve), with 212 patients (75%) remaining on treatment at study end. MSIS-29 total scores remained stable, while the MSIS-29 psychological scale showed significant improvement (p = 0.0015) at 2 years vs. baseline. TSQM scores at 2 years showed significant improvements in effectiveness (+ 6.6, p = 0.0001), convenience (+ 1.9, p = 0.0256), and global satisfaction (+ 8.1, p = 0.0001) vs. baseline. Disease progression was stable as indicated by non-significant changes in PDDS and EDSS vs. baseline. The ARR was low at 0.065, with a slightly higher ARR in previously treated (0.070) vs. naïve patients (0.058). Adherence was high at > 90%. Overall, 91 patients (32.3%) in the study reported a total of 215 safety events (32 serious, of which 21 were classified as mild-moderate). No new safety signals were observed.

CONCLUSIONS

These data highlight the importance of PROs to facilitate personalized treatment strategies in MS. In line with other teriflunomide studies, AURELIO showed stable QoL, efficacy and safety outcomes, and good treatment satisfaction both in treatment-naïve and previously treated patients in this Greek cohort of patients with RRMS.

NAD+ metabolism drives astrocyte proinflammatory reprogramming in central nervous system autoimmunity

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). Astrocytes are the most abundant glial cells in the CNS, and their dysfunction contributes to the pathogenesis of MS and its animal model, experimental autoimmune encephalomyelitis (EAE). Recent advances highlight the pivotal role of cellular metabolism in programming immune responses. However, the underlying immunometabolic mechanisms that drive astrocyte pathogenicity remain elusive. Nicotinamide adenine dinucleotide (NAD⁺) is a vital coenzyme involved in cellular redox reactions and a substrate for NAD⁺-dependent enzymes. Cellular NAD⁺ levels are dynamically controlled by synthesis and degradation, and dysregulation of this balance has been associated with inflammation and disease. Here, we demonstrate that cell-autonomous generation of NAD⁺ via the salvage pathway regulates astrocyte immune function. Inhibition of nicotinamide phosphoribosyltransferase (NAMPT), a key enzyme in the salvage pathway, results in depletion of NAD⁺, inhibits oxidative phosphorylation, and limits astrocyte inflammatory potential. We identified CD38 as the main NADase up-regulated in reactive mouse and human astrocytes in models of neuroinflammation and MS. Genetic or pharmacological blockade of astrocyte CD38 activity augmented NAD⁺ levels, suppressed proinflammatory transcriptional reprogramming, impaired chemotactic potential to inflammatory monocytes, and ameliorated EAE. We found that CD38 activity is mediated via calcineurin/NFAT signaling in mouse and human reactive astrocytes. Thus, NAMPT-NAD⁺-CD38 circuitry in astrocytes controls their ability to meet their energy demands and drives the expression of proinflammatory transcriptional modules, contributing to CNS pathology in EAE and, potentially, MS. Our results identify candidate therapeutic targets in MS.

Epidemiology and Pathophysiology of Multiple Sclerosis

PURPOSE OF REVIEW

This article provides an overview of genetic, environmental, and lifestyle risk factors affecting the disease course of multiple sclerosis (MS) and reviews the pathophysiologic characteristics of both relapsing and progressive MS.

RECENT FINDINGS

The prevalence of MS has increased in recent decades, and costs of care for patients with MS have risen dramatically. Black, Asian, and Hispanic individuals may be at risk for more severe MS-related disability. Multiple genetic MS risk factors have been identified. Factors such as low vitamin D levels and a history of Epstein-Barr virus, smoking, and obesity, especially during childhood, also influence MS risk. Traditionally thought to be a T-cell-mediated disease, recent research has highlighted the additional roles of B cells and microglia in both relapsing and progressive MS.

SUMMARY

Complex interactions between genetic, environmental, and lifestyle factors affect the risk for MS as well as the disease course. People of color have historically been underrepresented in both MS clinical trials and literature, but current research is attempting to better clarify unique considerations in these groups. MS pathology consists of the focal inflammatory lesions that have been well characterized in relapsing MS, as well as a more widespread neurodegenerative component that is posited to drive progressive disease. Recent advances in characterization of both the inflammatory and neurodegenerative aspects of MS pathophysiology have yielded potential targets for future therapeutic options.

Immune aging in multiple sclerosis is characterized by abnormal CD4 T cell activation and increased frequencies of cytotoxic CD4 T cells with advancing age

BACKGROUND

Immunosenescence (ISC) describes age-related changes in immune-system composition and function. Multiple sclerosis (MS) is a lifelong inflammatory condition involving effector and regulatory T-cell imbalance, yet little is known about T-cell ISC in MS. We examined age-associated changes in circulating T cells in MS compared to normal controls (NC).

METHODS

Forty untreated MS (Mean Age 43·3, Range 18-72) and 49 NC (Mean Age 48·6, Range 20-84) without inflammatory conditions were included in cross-sectional design. T-cell subsets were phenotypically and functionally characterized using validated multiparametric flow cytometry. Their aging trajectories, and differences between MS and NC, were determined using linear mixed-effects models.

FINDINGS

MS patients demonstrated early and persistent redistribution of naïve and memory CD4 T-cell compartments. While most CD4 and CD8 T-cell aging trajectories were similar between groups, MS patients exhibited abnormal age-associated increases of activated (HLA-DR+CD38+; (P = 0·013) and cytotoxic CD4 T cells, particularly in patients >60 (EOMES: P < 0·001). Aging MS patients also failed to upregulate CTLA-4 expression on both CD4 (P = 0·014) and CD8 (P = 0·009) T cells, coupled with abnormal age-associated increases in frequencies of B cells expressing costimulatory molecules.

INTERPRETATION

While many aspects of T-cell aging in MS are conserved, the older MS patients harbour abnormally increased frequencies of CD4 T cells with activated and cytotoxic effector profiles. Age-related decreased expression of T-cell co-inhibitory receptor CTLA-4, and increased B-cell costimulatory molecule expression, may provide a mechanism that drives aberrant activation of effector CD4 T cells that have been implicated in progressive disease.

FUNDING

Stated in Acknowledgements section of manuscript.

Thinking outside the box: non-canonical targets in multiple sclerosis

Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system that causes demyelination, axonal degeneration and astrogliosis, resulting in progressive neurological disability. Fuelled by an evolving understanding of MS immunopathogenesis, the range of available immunotherapies for clinical use has expanded over the past two decades. However, MS remains an incurable disease and even targeted immunotherapies often fail to control insidious disease progression, indicating the need for new and exceptional therapeutic options beyond the established immunological landscape. In this Review, we highlight such non-canonical targets in preclinical MS research with a focus on five highly promising areas: oligodendrocytes; the blood-brain barrier; metabolites and cellular metabolism; the coagulation system; and tolerance induction. Recent findings in these areas may guide the field towards novel targets for future therapeutic approaches in MS.

MSProDiscuss™ Clinical Decision Support Tool for Identifying Multiple Sclerosis Progression

This article describes the rationale for the development of the MSProDiscuss™ clinical decision support (CDS) tool, its development, and insights into how it can help neurologists improve care for patients with multiple sclerosis (MS). MS is a progressive disease characterized by heterogeneous symptoms and variable disease course. There is growing consensus that MS exists on a continuum, with overlap between relapsing–remitting and secondary progressive phenotypes. Evidence demonstrates that neuroaxonal loss occurs from the outset, that progression can occur independent of relapse activity, and that continuous underlying pathological processes may not be reflected by inflammatory activity indicative of the patient’s immune response. Early intervention can benefit patients, and there is a need for a tool that assists physicians in rapidly identifying subtle signs of MS progression. MSProDiscuss, developed with physicians and patients, facilitates a structured approach to patient consultations. It analyzes multidimensional data via an algorithm to estimate the likelihood of progression (the MSProDiscuss score), the contribution of various symptoms, and the impact of symptoms on daily living, enabling a more personalized approach to treatment and disease management. Data from CDS tools such as MSProDiscuss offer new insights into disease course and facilitate informed decision-making and a holistic approach to MS patient care.

Repurposing Histaminergic Drugs in Multiple Sclerosis

Multiple sclerosis is an autoimmune disease with a strong neuroinflammatory component that contributes to severe demyelination, neurodegeneration and lesions formation in white and grey matter of the spinal cord and brain. Increasing attention is being paid to the signaling of the biogenic amine histamine in the context of several pathological conditions. In multiple sclerosis, histamine regulates the differentiation of oligodendrocyte precursors, reduces demyelination, and improves the remyelination process. However, the concomitant activation of histamine H1–H4 receptors can sustain either damaging or favorable effects, depending on the specifically activated receptor subtype/s, the timing of receptor engagement, and the central versus peripheral target district. Conventional drug development has failed so far to identify curative drugs for multiple sclerosis, thus causing a severe delay in therapeutic options available to patients. In this perspective, drug repurposing offers an exciting and complementary alternative for rapidly approving some medicines already approved for other indications. In the present work, we have adopted a new network-medicine-based algorithm for drug repurposing called SAveRUNNER, for quantifying the interplay between multiple sclerosis-associated genes and drug targets in the human interactome. We have identified new histamine drug-disease associations and predicted off-label novel use of the histaminergic drugs amodiaquine, rupatadine, and diphenhydramine among others, for multiple sclerosis. Our work suggests that selected histamine-related molecules might get to the root causes of multiple sclerosis and emerge as new potential therapeutic strategies for the disease.

Autologous Hematopoietic Stem Cell Transplantation for Multiple Sclerosis, the Ottawa Protocol

Autologous hematopoietic stem cell transplantation (aHSCT) is increasingly used to treat patients with highly active multiple sclerosis (MS) refractory to disease-modifying therapy. Briefly, cyclophosphamide and filgrastim are used to mobilize autologous hematopoietic stem cells (HSC) into the circulation. HSC are harvested by leukapheresis, purified using a CD34 immunomagnetic selection process, and cryopreserved. Busulphan, cyclophosphamide, and rabbit anti-thymocyte globulin are used to destroy the patient's autoreactive immune system, followed by infusion of the previously collected HSC, which reconstitute a naïve and self-tolerant immune system. Many MS patients experience durable remissions with no evidence of new disease activity following aHSCT. Treatment-related toxicity is rare, but potentially life-threatening complications necessitate appropriate patient selection by MS neurologists and HSCT physicians. AHSCT must be performed with a highly trained multidisciplinary team expert to minimize morbidity and mortality. We present the current aHSCT procedure for an MS indication at The Ottawa Hospital, developed from our program's 20-year experience. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Candidate selection Basic Protocol 2: Autologous hematopoietic stem cell mobilization, collection, purification, and cryopreservation Basic Protocol 3: Autologous hematopoietic stem cell transplantation Basic Protocol 4: Supportive care following recovery from aHSCT (Beyond 100 days) Basic Protocol 5: Ongoing evaluation of multiple sclerosis.

Axonal injury in asymptomatic individuals preceding onset of multiple sclerosis

Axonal loss is the main cause of irreversible disability in multiple sclerosis (MS). Serum neurofilament light (sNfL) is a biomarker of axonal disintegration. In this nested case-control study, blood samples from 519 presymptomatic persons (age range 4-39 years) who later received an MS diagnosis showed higher sNfL concentrations than 519 matched controls (p < 0.0001), noticeable at least 10 years before clinical MS onset. Mean values for pre-MS and control groups were 9.6 pg/mL versus 7.4 pg/mL 0-5 years before onset, and 6.4 pg/mL versus 5.8 pg/mL 5-10 years before onset. These results support that axonal injury occurs early in MS pathogenesis.

Cognitive Impairment in Secondary Progressive Multiple Sclerosis: Effect of Disease Duration, Age, and Progressive Phenotype

Background: Cognitive deficits are common in multiple sclerosis (MS) and affect patients at all stages of the disease, regardless of phenotype. Aims: This literature review focuses the cognitive deficits observed in secondary progressive MS (SPMS). It is mainly based on studies that compared the frequency and main characteristics of cognitive deficits in SPMS with other phenotypes. Methods: A bibliographic search was carried out using the PubMed database with the following keywords: multiple sclerosis, secondary-progressive, cognition. Results: Thirteen studies were initially selected that were published in English, reporting the neuropsychological data of a sample of at least 30 patients with SPMS, comparing them with patients with other phenotypes. Studies suggest that there is an association between the duration of the disease and the frequency and extent of the cognitive disorders. Studies also showed that the SP form is associated with an increased frequency of cognitive impairment and with an increased severity as compared to relapsing-remitting MS (RRMS). Compared to RRMS, progressive forms of MS are associated with more severe impairment in certain cognitive areas, such as episodic verbal memory, information processing speed, working memory, or verbal fluency. Two studies showed that cognitive performances decline overtime in SPMS. Conclusion: Cognitive disorders are more frequent and more severe in the SP form than in relapsing course of MS. The profile of cognitive impairment encountered in the SP form also appears to be different from those found in the other phenotypes.

Neuropathic Pain in Multiple Sclerosis and Its Animal Models: Focus on Mechanisms, Knowledge Gaps and Future Directions

Multiple sclerosis (MS) is a multifaceted, complex and chronic neurological disease that leads to motor, sensory and cognitive deficits. MS symptoms are unpredictable and exceedingly variable. Pain is a frequent symptom of MS and manifests as nociceptive or neuropathic pain, even at early disease stages. Neuropathic pain is one of the most debilitating symptoms that reduces quality of life and interferes with daily activities, particularly because conventional pharmacotherapies do not adequately alleviate neuropathic pain. Despite advances, the mechanisms underlying neuropathic pain in MS remain elusive. The majority of the studies investigating the pathophysiology of MS-associated neuropathic pain have been performed in animal models that replicate some of the clinical and neuropathological features of MS. Experimental autoimmune encephalomyelitis (EAE) is one of the best-characterized and most commonly used animal models of MS. As in the case of individuals with MS, rodents affected by EAE manifest increased sensitivity to pain which can be assessed by well-established assays. Investigations on EAE provided valuable insights into the pathophysiology of neuropathic pain. Nevertheless, additional investigations are warranted to better understand the events that lead to the onset and maintenance of neuropathic pain in order to identify targets that can facilitate the development of more effective therapeutic interventions. The goal of the present review is to provide an overview of several mechanisms implicated in neuropathic pain in EAE by summarizing published reports. We discuss current knowledge gaps and future research directions, especially based on information obtained by use of other animal models of neuropathic pain such as nerve injury.

Assessing the immune response to SARS-CoV-2 mRNA vaccines in siponimod-treated patients: a nonrandomized controlled clinical trial (AMA-VACC)

Background:

Systematic data are lacking on the immune response toward SARS-CoV-2 mRNA vaccination in SPMS patients on disease-modifying therapies (DMTs).

Objective:

The AMA-VACC clinical trial was designed to characterize immune responses to SARS-CoV-2 mRNA vaccines in siponimod-treated SPMS patients.

Design:

AMA-VACC is an ongoing three-cohort, multicenter, open-label, prospective clinical study.

Methods:

The study included patients at risk for SPMS or patients with SPMS diagnosis. Patients received SARS-CoV-2 mRNA vaccine as part of their clinical routine during ongoing siponimod treatment (cohort 1), during siponimod treatment interruption (cohort 2), or while on dimethyl fumarate, glatiramer acetate, beta-interferons, teriflunomide, or no current therapy (cohort 3). SARS-CoV-2-specific neutralizing antibodies and T-cell responses were measured 1 week and 1 month after the second dose of vaccination.

Results:

In total, 17 patients, 4 patients, and 20 patients were recruited into cohorts 1, 2, and 3, respectively. The primary endpoint of seroconversion for SARS-CoV-2-neutralizing antibodies at week 1 was reached by 52.9%, 75.0%, and 90.0% of patients in cohorts 1, 2, and 3, respectively. For 64.7% of patients in cohort 1, all patients in cohort 2, and 95% of patients in cohort 3, seroconversion was observed at either week 1 or month 1 or both time points. After 1 week, 71.4% of cohort 1, 75.0% of cohort 2, and 85.0% of cohort 3 were positive for either SARS-CoV-2-neutralizing antibodies or SARS-CoV-2-specific T-cells or both. After 1 month, the rates were 56.3%, 100.0%, and 95.0%, respectively.

Conclusion:

The study shows that the majority of siponimod patients mount humoral and cellular immune response under continuous siponimod treatment. The data do not sufficiently support interruption of treatment for the purpose of vaccination.

Registration:

EU Clinical Trials Register: EudraCT 2020-005752-38 (www.clinicaltrialsregister.eu); ClinicalTrials.gov: NCT04792567 (https://clinicaltrials.gov).

S100B Protein as a Therapeutic Target in Multiple Sclerosis: The S100B Inhibitor Arundic Acid Protects from Chronic Experimental Autoimmune Encephalomyelitis

S100B is an astrocytic protein behaving at high concentration as a damage-associated molecular pattern molecule. A direct correlation between the increased amount of S100B and inflammatory processes has been demonstrated, and in particular, the inhibitor of S100B activity pentamidine has been shown to ameliorate clinical scores and neuropathologic-biomolecular parameters in the relapsing-remitting experimental autoimmune encephalomyelitis mouse model of multiple sclerosis. This study investigates the effect of arundic acid (AA), a known inhibitor of astrocytic S100B synthesis, in the chronic experimental autoimmune encephalomyelitis, which is another mouse model of multiple sclerosis usually studied. By the daily evaluation of clinical scores and neuropathologic-molecular analysis performed in the spinal cord, we observed that the AA-treated group showed lower severity compared to the vehicle-treated mice, particularly in the early phase of disease onset. We also observed a significant reduction of astrocytosis, demyelination, immune infiltrates, proinflammatory cytokines expression and enzymatic oxidative reactivity in the AA-treated group. Overall, our results reinforce the involvement of S100B in the development of animal models of multiple sclerosis and propose AA targeting the S100B protein as a focused potential drug to be considered for multiple sclerosis treatment.

Humoral immune response to COVID-19 vaccines in people with secondary progressive multiple sclerosis treated with siponimod

The aim of this study is to determine a development of humoral response after COVID-19 vaccination in persons with secondary progressive multiple sclerosis (pwSPMS) on siponimod, compared to healthy controls (HC).Methods: In 13 pwSPMS taking siponimod and 11 HC, testing for SARS-CoV2 antibodies was performed after vaccination against COVID-19.Results: pwSPMS taking siponimod had a significantly lower titer of SARS-CoV2 antibodies compared to healthy controls (19.4 (0-250) vs. 250 (250), p>0.001). Two (15.4%) pwSPMS on siponimod had unmeasurable titers of SARS-CoV2-2 antibodies, while all HC had positive titers.Conclusion: Although the results of this study are limited by a small sample size, results have consistently shown low titers of SARS-CoV-2 IgG after COVID-19 vaccinations in pwSPMS on siponimod.

High-dose biotin for multiple sclerosis: A systematic review and meta-analyses of randomized controlled trials

BACKGROUND

Biotin may activate the acetyl-CoA-, 3-methylcrotonyl-CoA-, propionyl-CoA-, and pyruvate carboxylases to increase myelin repair and/or synthesis, and may enhance the production of adenosine triphosphate (ATP), which may be essential to prevent neurodegeneration. The purpose of this review was to determine the effectiveness and safety of high-dose biotin (HDB) in multiple sclerosis via a systematic review of randomized controlled trials.

METHODS

We searched the following electronic databases for relevant articles: MEDLINE, CENTRAL, EMBASE, Scopus, and ClinicalTrials.gov website until April 2021. We considered randomized clinical trials (RCTs) that involved adult patients diagnosed with any phenotype of multiple sclerosis that conforms with the McDonald 2010/2017 criteria or the Lublin 2014 criteria. We included studies employing high-dose biotin or "MD1003" administered orally for at least 300 mg/day and given for at least three months. The methodological quality assessment of the included studies was done using the Cochrane Risk of Bias (RoB) tool. The GRADE approach was used to assess the certainty of evidence [COE].

RESULTS

Out of 366 records identified, three RCTs involving 889 individuals diagnosed with MS (830 participants had progressive MS (PMS); 59 had RRMS) were pooled for analyses. The overall female:male ratio was 1.16:1. All included trials used HDB as an adjunctive treatment. The risks of bias in the three studies were low across the domains. At 12 to 15 months, there is insufficient evidence that the HDB and placebo arms differed in terms of composite improvement of MS-related disability (relative risk (RR) 2.87; 95% CI 0.29-28.40; 2 trials; 796 participants; I² = 66%) [low COE], improvement in expanded disability status scale (IEDSS) (RR 2.27; 95% CI 0.25-20.98; 2 trials; 796 participants; I² = 63%) [low COE], and both IEDSS and improvement in 25-foot walk time (ITW25) (IEDSS-ITW25) (RR 0.58; 95% CI 0.17-2.00; 2 trials; 796 participants; I² = 13%) [moderate COE] among patients with PMS. Pooled data for ITW25 at 12 to 15 months yielded statistical significance (RR 2.06; 95% CI 1.04-4.09; 2 trials; 796 participants; I² = 0%) [moderate COE] favoring HDB among patients with PMS. At 12 to 15 months, no significant differences were found in terms of mean change in EDSS (MD -0.06; 95% CI -0.14-0.02; 2 studies; 796 participants; 889 participants; I² = 68%) among patients with PMS. Synthesized data on incidence of any AEs (RR 0.98; 95% CI 0.92-1.04; 3 trials; I² = 0%) [high COE] and any serious AEs (RR 0.98; 95% CI 0.77-1.24; 3 trials; 889 participants; I² = 0%) [moderate COE] were not significantly different between HDB and placebo groups. Out of 662 pooled patients in the HDB group, 31 patients (4.7%) were found to have laboratory test interference compared to zero event in the pooled placebo group [high COE].

CONCLUSIONS

A moderate certainty of evidence suggests a potential benefit in favor of HDB administered for 12 to 15 months in terms of ITW25 in patients with PMS. However, an important trade-off of this benefit is the high certainty of evidence suggesting an increased incidence of laboratory test interference when HDB is taken.