SYNE1 ataxia is a rare representative of autosomal recessive hereditary cerebellar ataxias (ARCAs). It was originally described in the Beauce region of Quebec as a pure cerebellar form of ataxia. Later, more complex phenotypes with a wide range of extra-cerebellar neurological and non-neurological dysfunctions were discovered in other geographical locations. SYNE1 deficiency was predominantly linked to nonsense and frameshift variants; however, missense variants in the gene SYNE1 have also been described as causative for this type of ataxia. We here describe a case of an adult female patient with a phenotype of progressive ataxic features over 15 years, combined with spastic paraparesis. Non-neurological symptoms were not present. The family history was negative, and the case was classified as sporadic. However, the parents of the patient were related to both grandmothers, being cousins. DNA was sequenced using the Illumina HiSeq/Nova Seq system, and the variant c.23413A>G; p.Arg7805Gly in the gene SYNE1 was found in a homozygous state (NM_033071.4; NP_149062.2). This missense variant has not been described in the literature and is not listed in the relevant databases. This homozygous substitution resulted in an amino acid change, arginine for glycine, in a highly conserved region of the SYNE1 gene. According to ACMG/ACGS guidelines, the criteria PM2+PM3_supporting+PP3 were applied, which classified the substitution c.23413A>G; p.Arg7805Gly as “a variant of uncertain significance.” The calculated effect of this substitution is mostly pathogenic based on several in silico prediction programs. The presence of spastic paraparesis grades this case as an ataxic complex syndrome. This is the first SYNE1 ataxia patient of Polish origin with a novel missense variant described with full clinical and MRI data.

B-cell depletion with anti-CD20 monoclonal antibody (mAb) represents a novel and highly effective treatment for patients with multiple sclerosis. Although all approved anti-CD-20 mAbs for multiple sclerosis (MS) treatment, ocrelizumab, ofatumumab, and ublituximab, target the same molecule on the B-cell surface, some differences in their molecular structure translate into important distinctions in their mechanisms of B-cell depletion. Differences between an antibody-dependent cell-mediated cytotoxicity (ADCC) versus a complement-dependent cytotoxicity (CDC) in anti-CD20 mAbs mechanism of action correspond to deeper B-cell depletion as well as better tolerability. Glycoengineering of the Fc portion of ublituximab with reduced fucosylation enhances affinity to Fc gamma receptor IIIa (FcγRIIIa) on natural killer (NK) cells. This molecular modification of ublituximab exhibits significantly higher ADCC activity in relation to CDC in B-cell depletion mechanisms. In addition, glycoengineering of ublituximab reduces the importance of the FcγRIIIa 158V/F polymorphism, which influences the effectiveness of B-cell depletion. In the ULTIMATE I and II studies, ublituximab showed a significant reduction in annual relapse rate versus teriflunomide in relapsing MS patients and strikingly reduced active and new/enlarging MRI lesions. Ublituximab also showed efficacy on the disease progression and increased disability improvement in the extended 5-year observation study. The advantage of ublituximab also correlates with good tolerability and reduced infusion-related reactions. Ublituximab infusion, 1 h, is significantly shorter in comparison to other intravenous (IV) preparations of anti-CD20 mAbs. Thus, ublituximab provides better convenience to MS patients as well as saves the time of healthcare providers.

SYNE1 ataxia is a rare representative of autosomal recessive hereditary cerebellar ataxias (ARCAs). It was originally described in the Beauce region of Quebec as a pure cerebellar form of ataxia. Later, more complex phenotypes with a wide range of extra-cerebellar neurological and non-neurological dysfunctions were discovered in other geographical locations. SYNE1 deficiency was predominantly linked to nonsense and frameshift variants; however, missense variants in the gene SYNE1 have also been described as causative for this type of ataxia. We here describe a case of an adult female patient with a phenotype of progressive ataxic features over 15 years, combined with spastic paraparesis. Non-neurological symptoms were not present. The family history was negative, and the case was classified as sporadic. However, the parents of the patient were related to both grandmothers, being cousins. DNA was sequenced using the Illumina HiSeq/Nova Seq system, and the variant c.23413A>G; p.Arg7805Gly in the gene SYNE1 was found in a homozygous state (NM_033071.4; NP_149062.2). This missense variant has not been described in the literature and is not listed in the relevant databases. This homozygous substitution resulted in an amino acid change, arginine for glycine, in a highly conserved region of the SYNE1 gene. According to ACMG/ACGS guidelines, the criteria PM2+PM3_supporting+PP3 were applied, which classified the substitution c.23413A>G; p.Arg7805Gly as "a variant of uncertain significance." The calculated effect of this substitution is mostly pathogenic based on several in silico prediction programs. The presence of spastic paraparesis grades this case as an ataxic complex syndrome. This is the first SYNE1 ataxia patient of Polish origin with a novel missense variant described with full clinical and MRI data.

Anti-CD20 monoclonal antibodies represent a particularly important class of drugs in the treatment of multiple sclerosis. This results from the discovery of the instrumental function of B cells in the initiation of multiple sclerosis autoimmunity, as well as their role in the protraction of the disease process. Ofatumumab is the first fully human anti-CD20 monoclonal antibody. Phase 2 and 3 trials demonstrated high efficacy of ofatumumab in a population of patients with the relapsing-remitting and relapsing form of multiple sclerosis. Ofatumumab very efficiently decreased number of relapses. In comparison to placebo or the active comparator, teriflunomide, the annual relapse rate was reduced by more than 50%. Even more spectacular efficacy was demonstrated in the reduction of active magnetic resonance imaging lesions. Compared to teriflunomide, the number of gadolinium-enhancing lesions was reduced by more than 90%. In the pooled population from both phase 3 studies, ofatumumab also reduced the risk for disability progression. These data allow for the classification of ofatumumab in the group of high-efficacy treatment agents for multiple sclerosis. In a protracted disorder like multiple sclerosis, it is critically important to understand long-term efficacy and safety. To date, six-year data are available on ofatumumab treatment in relapsing-remitting multiple sclerosis. These results confirm the high efficacy of ofatumumab in long-term treatment in the population of relapsing-remitting multiple sclerosis patients.

Introduction and objective: Ocrelizumab is used in multiple sclerosis treatment and is available in intravenous and subcutaneous forms. In Poland, only the intravenous form is currently reimbursed. The subcutaneous form offers a shorter administration time, potentially benefiting both healthcare providers and patients. This study evaluates the impact of the different forms of ocrelizumab administration on medical facility workflow and costs. Materials and methods: A survey was conducted in six medical centres involving 329 patients treated with ocrelizumab in 2023, with 46 patients receiving the subcutaneous form of the drug. The study assessed the complete drug administration process, including premedication, preparation, administration, and post-administration observation. The comparison between the two forms of ocrelizumab focused on the costs associated with drug administration, the time patients spent at the medical centre, and the efficiency of the drug administration process. Results: The administration costs of the subcutaneous form were significantly lower (96.80 PLN) than the intravenous form (224.32 PLN). The time patients spent at the medical centre was greatly reduced for the subcutaneous form (56 minutes) compared to the intravenous form (242 minutes). Efficiency in drug administration was also higher for the subcutaneous (26.88) than the intravenous form (2.62). Conclusions: The study highlights the substantial benefits of the subcutaneous form of ocrelizumab over the intravenous form. These advantages are noticeable from both the healthcare provider’s and patient’s perspectives, underscoring the potential for improved efficiency and patient experience with the subcutaneous form.

Almost all currently licensed disease-modifying therapies (DMTs) for MS treatment require prolonged if not lifelong administration. Yet, as people age, the immune system has increasingly reduced responsiveness, known as immunosenescence. Many MS DMTs reduce the responsiveness of the immune system, increasing the risks for infections and possibly cancers. As people with MS (pwMS) age, it is recognized that inflammatory MS activity declines. Several studies have addressed de-escalation of DMTs for relapsing MS under special circumstances. Here, we review evidence for de-escalating DMTs as a strategy that is particularly relevant to pwMS of older age. Treatment de-escalation can involve various strategies, such as extended or reduced dosing, switching from high-efficacy DMTs having higher risks to moderately effective DMTs with lesser risks, or treatment discontinuation. Studies have suggested that for natalizumab extended dosing maintained clinical efficacy while reducing the risk of PML. Extended interval dosing of ocrelizumab mitigated the decline of Ig levels. Retrospective and observational discontinuation studies demonstrate that age is an essential modifier of drug efficacy. Discontinuation of MS treatment in older patients has been associated with a stable disease course, while younger patients who discontinued treatment were more likely to experience new clinical activity. A recently completed 2-year randomized-controlled discontinuation study in 260 stable pwMS > 55 years found stable clinical multiple sclerosis with only a small increased risk of new MRI activity upon discontinuation. DMT de-escalation or discontinuation in MS patients older than 55 years may be non-inferior to continued treatment with immunosuppressive agents having higher health risks. However, despite several small studies, a definite conclusion about treatment de-escalation in older pwMS will require larger and longer studies. Ideally, comparison of de-escalation versus continuation versus discontinuation of DMTs should be done by prospective randomized-controlled trials enrolling sufficient numbers of subjects to allow comparisons for MS patients of both sexes within age groups, such as 55–59, 60–65, 66–69, etc. Optimally, such studies should be 3 years or longer and should incorporate testing for specific markers of immunosenescence (such as T-cell receptor excision circles) to account for differential aging of individuals.

Ocrelizumab is the first anti-CD20 monoclonal antibody approved for the treatment of relapsing and primary progressive multiple sclerosis. Ocrelizumab is administered intravenously (i.v.) at a dose of 600 mg every six months. It is a highly effective drug strongly inhibiting inflammatory changes in the central nervous system, which nearly completely prevents the development of new active magnetic resonance imaging lesions and clinical relapses. Pharmacokinetic studies and data from post hoc analyses of ocrelizumab pivotal studies suggest that a higher dose than the current dose level might have a stronger therapeutic impact. These results revealed that higher ocrelizumab exposure dependent on lower body mass correlated with increased B cell depletion and reduced risk of disability progression independent of relapse activity (PIRA). In addition, higher ocrelizumab exposure showed a correlation with decreased development of new and enlarging T2 magnetic resonance imaging lesions. Two randomised studies are currently under way to compare the efficacy and safety of the standard i.v. dose of 600 mg versus higher doses (1,200 mg or 1,800 mg) in multiple sclerosis patients. Another new direction in the development of ocrelizumab therapy in multiple sclerosis is subcutaneous (s.c.) drug administration. Recent data from the OCARINA study revealed that s.c. ocrelizumab was not inferior to the i.v. administration with respect to pharmacokinetics, magnetic resonance imaging activity, and clinical relapses. The safety of s.c. ocrelizumab was found to be comparable to the i.v. form, with a higher rate of mild local injection reactions.

Circular RNA (circRNA) molecules represent a novel and unique class of endogenous non-coding RNAs controlling the expression and function of microRNA (miRNA) and post-transcriptional regulation. Recent studies implicated circRNA in the pathomechanism of multiple sclerosis (MS). Hybridization microarray was used to define the circRNA profile in the peripheral blood mononuclear cells (PBMCs) from 20 untreated patients with relapsing–remitting MS (RRMS: 10 in relapse, 10 in remission) and 10 healthy controls (HCs). We analyzed close to 14,000 individual circRNAs per sample. The discovery set data were validated using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) with an independent cohort of 45 RRMS patients (18 in relapse, 27 in remission) and 27 HCs. Microarray analysis revealed 246 circRNAs differentially downregulated ( P < 0.05) in RRMS patients versus HCs. We validated two circRNAs of the three showing the lowest levels of differential expression in the RRMS remission group versus the HC group: hsa_circRNA_101145 and hsa_circRNA_001896. Their expression was significantly decreased during remission in RRMS ( P = 0.0000332, FC = 0.385 and P = 0.0455, FC = 0.591, respectively) and in patients showing a lower level of disability (hsa_circRNA_101145, P = 0.0695; hsa_circRNA_001896, P = 0.0008). Bioinformatic analysis revealed 10 miRNAs interacting with these circRNAs in a complementary manner and led to the discovery of three protein-coding mRNAs downregulated in patients with RRMS during remission. These transcripts have been previously implicated in oxidative stress, blood–brain barrier permeability, microglia function, and extracellular matrix molecules altering the microenvironment and inhibiting oligodendrocyte progenitor cells. circRNAs displayed a distinct profile in PBMCs from patients with RRMS, and our results may implicate circRNAs with low expression in important mechanistic pathways of RRMS.

BACKGROUND AND OBJECTIVES:To investigate the total circular RNA (circRNA) profile in patients with relapsing-remitting multiple sclerosis (RRMS) and healthy controls (HCs).METHODS:Hybridization microarray was used to define the circRNA profile in peripheral blood mononuclear cells (PBMCs) from 20 untreated patients with RRMS (10 in relapse and 10 in remission) and 10 HCs. We analyzed close to 14,000 individual circRNAs per sample. The discovery set data were validated using quantitative reverse transcription-PCR with an independent cohort of 47 patients with RRMS (19 in relapse and 28 in remission) and 27 HCs.RESULTS:Microarray analysis revealed 914 transcripts to be differentially expressed between patients with RRMS in relapse and HCs (p < 0.05). We validated 3 circRNAs from 5 showing highest levels of differential expression in the RRMS relapse vs HC group: hsa_circRNA_101348, hsa_circRNA_102611, and hsa_circRNA_104361. Their expression was significantly increased during relapse in RRMS (p = 0.0002, FC = 2.9; p = 0.01, FC = 1.6; and p = 0.001, FC = 1.5, respectively) and in patients showing gadolinium enhancement on brain MRI (hsa_circRNA_101348, p = 0.0039, FC = 2.4; hsa_circRNA_104361, p = 0.029, FC = 1.7). Bioinformatic analysis revealed 15 microRNAs interacting with these circRNAs in a complementary manner and led to the discovery and validation of 3 protein-coding RNAs upregulated in patients with RRMS during relapse. Two of these, AK2 and IKZF3, have previously been implicated in B-cell function.DISCUSSION:circRNAs display a distinct profile in PBMCs from patients with RRMS, and our results may implicate circRNA in the known disturbed B-cell activity in RRMS and thus represent a novel biomarker for monitoring relapse activity.

Neuromyelitis optica spectrum disorders (NMOSD) are inflammatory demyelinating diseases of the central nervous system (CNS) that cause optic neuritis, transverse myelitis, and some other CNS syndromes. Recently, diagnosis and understanding of these diseases has been markedly enhanced by the discovery that serum autoantibodies that target aquaporin-4 (AQP4) are strongly associated with the disease. This spectrum includes also a potential subset of patients with a phenotype of NMOSD who have anti-myelin oligodendrocyte glycoprotein (MOG) antibody. Although steroids and immunosuppressive drugs have been widely used for NMOSD treatment, until recently there was no approved therapy for these diseases. With improved understanding of the pathophysiology of NMOSD, numerous new therapeutic strategies have recently been evaluated. The results of these studies, involving monoclonal antibodies (mAbs) inhibiting terminal complement protein cleavage interfering with interleukin-6 receptor (IL-6 R) signaling and depleting CD19-positive B cells, have been published in recent months. All of these new therapeutics have shown a high degree of efficacy in diminishing NMOSD activity and inhibiting disability progression. At the same time, all these mAbs have demonstrated favorable safety and tolerability profiles, with a limited rate of adverse events. The first of these new drugs, eculizumab, have been approved in USA and Europe for NMOSD treatment within the last couple of months and it is expected that the other novel, effective and safe treatments for NMOSD will be approved in the near future.

ObjectiveAccumulating evidence supports a role for exosomes in immune regulation. In this study, we investigated the total circulating exosome transcriptome in relapsing–remitting multiple sclerosis (RRMS) patients and healthy controls (HC).MethodsNext generation sequencing (NGS) was used to define the global RNA profile of serum exosomes in 19 RRMS patients (9 in relapse, 10 in remission) and 10 HC. We analyzed 5 million reads and >50,000 transcripts per sample, including a detailed analysis of microRNAs (miRNAs) differentially expressed in RRMS. The discovery set data were validated by quantification using digital quantitative polymerase chain reaction with an independent cohort of 63 RRMS patients (33 in relapse, 30 in remission) and 32 HC.ResultsExosomal RNA NGS revealed that of 15 different classes of transcripts detected, 4 circulating exosomal sequences within the miRNA category were differentially expressed in RRMS patients versus HC: hsa‐miR‐122‐5p, hsa‐miR‐196b‐5p, hsa‐miR‐301a‐3p, and hsa‐miR‐532‐5p. Serum exosomal expression of these miRNAs was significantly decreased during relapse in RRMS. These miRNAs were also decreased in patients with a gadolinium enhancement on brain magnetic resonance imaging. In vitro secretion of these miRNAs by peripheral blood mononuclear cells was also significantly impaired in RRMS.InterpretationThese data show that circulating exosomes have a distinct RNA profile in RRMS. Because putative targets for these miRNAs include the signal transducer and activator of transcription 3 and the cell cycle regulator aryl hydrocarbon receptor, the data suggest a disturbed cell‐to‐cell communication in this disease. Thus, exosomal miRNAs might represent a useful biomarker to distinguish multiple sclerosis relapse. Ann Neurol 2017;81:703–717

BACKGROUND:Exosomes are small extracellular vesicles that provide cell-to-cell communication and are involved in immunoregulation. OBJECTIVE:To investigate serum exosomes for the presence of myelin proteins outside the central nervous system (CNS) and their role in multiple sclerosis (MS). METHODS:Serum, cerebrospinal fluid (CSF), and peripheral blood mononuclear cell (PBMC) samples were collected from 45 patients with relapsing-remitting MS (RRMS), 30 patients with secondary progressive MS (SPMS), and 45 healthy controls. Exosomes were isolated using a polymer formulation method, and their size, concentration, and CNS myelin protein contents were measured by a nanoparticle tracking analysis, enzyme-linked immunosorbent assays, and Western blot. RESULTS:We found that exosomes expressed three major myelin proteins, myelin basic protein, proteolipid protein, and myelin oligodendrocyte glycoprotein (MOG). Exosomal content of MOG strongly correlated with disease activity and was highest in RRMS patients in relapse and in SPMS patients. Serum-derived exosomes induced proliferation of MOG-T cell receptor transgenic T cells confirming that serum exosomes maintained MOG immunogenicity. CONCLUSION:Exosomes isolated outside CNS tissue expressed myelin proteins, and the presence of MOG correlated strongly with disease activity. We conclude that exosomes might enhance and/or perpetuate anti-myelin immune reactions in MS and may provide novel markers of disease activity.

Multiple sclerosis (MS) is a putative autoimmune disease of the central nervous system (CNS) in which autoreactive immune cells recognizing myelin antigens lead to demyelination and axonal injury. Mechanisms relevant to the pathogenesis of MS have not been fully elucidated, particularly those underlying initiation of immune system dysfunction. For example, it is not known how reactivity against CNS components is generated within the peripheral immune system. In this review, we propose that a significant contribution to the immunoregulatory events may derive from a cell-to-cell communication system involving the production, secretion and transfer of extracellular vesicles known as exosomes. Herein, we discuss in detail the biogenesis and roles of these cell surface-generated vesicles from the standpoint of receptors and their cargo, microRNA. It is well known that exosomes can cross the blood–brain barrier and thus may contribute to the spread of brain antigens to the periphery. Further understanding of exosome-dependent mechanisms in MS should provide a novel angle to the analysis of the pathogenesis of this disease. Finally, we launch the idea that exosomes and their contents may serve as biomarkers in MS.