B-cell depletion with rituximab in relapsing-remitting multiple sclerosis

Cellular therapies in rheumatic and musculoskeletal diseases

A substantial proportion of patients diagnosed with rheumatologic and musculoskeletal diseases (RMDs) exhibit resistance to conventional therapies or experience recurrent symptoms. These diseases, which include autoimmune disorders such as multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus, are marked by the presence of autoreactive B cells that play a critical role in their pathogenesis. The persistence of these autoreactive B cells within lymphatic organs and inflamed tissues impairs the effectiveness of B-cell-depleting monoclonal antibodies like rituximab. A promising therapeutic approach involves using T cells genetically engineered to express chimeric antigen receptors (CARs) that target specific antigens. This strategy has demonstrated efficacy in treating B-cell malignancies by achieving long-term depletion of malignant and normal B cells. Preliminary data from patients with RMDs, particularly those with lupus erythematosus and dermatomyositis, suggest that CAR T-cells targeting CD19 can induce rapid and sustained depletion of circulating B cells, leading to complete clinical and serological responses in cases that were previously unresponsive to conventional therapies. This review will provide an overview of the current state of preclinical and clinical studies on the use of CAR T-cells and other cellular therapies for RMDs. Additionally, it will explore potential future applications of these innovative treatment modalities for managing patients with refractory and recurrent manifestations of these diseases.

Current state and perspectives of CAR T cell therapy in central nervous system diseases

B cell-directed CAR T cell therapy has fundamentally changed the treatment of haematological malignancies, and its scope of application is rapidly expanding to include other diseases such as solid tumours or autoimmune disorders. Therapy-refractoriness remains an important challenge in various inflammatory and non-inflammatory disorders of the CNS. The reasons for therapy failure are diverse and include the limited access current therapies have to the CNS, as well as enormous inter- and intra-individual disease heterogeneity. The tissue-penetrating properties of CAR T cells make them a promising option for overcoming this problem and tackling pathologies directly within the CNS. First application of B cell-directed CAR T cells in neuromyelitis optica spectrum disorder and multiple sclerosis patients has recently revealed promising outcomes, expanding the potential of CAR T cell therapy to encompass CNS diseases. Additionally, the optimization of CAR T cells for the therapy of gliomas is a growing field. As a further prospect, preclinical data reveal the potential benefits of CAR T cell therapy in the treatment of primary neurodegenerative diseases such as Alzheimer's disease. Considering the biotechnological optimizations in the field of T cell engineering, such as extension to target different antigens or variation of the modified T cell subtype, new and promising fields of CAR T cell application are rapidly opening up. These innovations offer the potential to address the complex pathophysiological properties of CNS diseases. To use CAR T cell therapy optimally to treat CNS diseases in the future while minimizing therapy risks, further mechanistic research and prospective controlled trials are needed to assess seriously the disease and patient-specific risk-benefit ratio.

Different Treatment Outcomes of Multiple Sclerosis Patients Receiving Ocrelizumab or Ofatumumab

OBJECTIVE

B-cell-depletion via CD20 antibodies is a safe and effective treatment for active relapsing multiple sclerosis (RMS). Both ocrelizumab (OCR) and ofatumumab (OFA) have demonstrated efficacy in randomized controlled trials and are approved for treatment of RMS, yet nothing is known on their comparative effectiveness, especially in the real-world setting.

METHODS

This prospective cohort study includes patients that were started on either OCR or OFA between September 2021 and December 2023. Patients were followed until June 2024 and recruited at 3 large tertiary centers in Germany (Duesseldorf, Essen, and Giessen). Propensity-score-matching was used to address baseline imbalances among patients. Clinical relapses, presence of new or enlarging MRI lesions and 6-month confirmed disability worsening were evaluated. Non-inferiority of OFA compared to OCR was evaluated through comparison of Kaplan-Meier-estimates.

RESULTS

A total of 1,138 patients were initially enrolled in the cohort. Following patient selection and propensity-score-matching, 544 OCR and 417 OFA patients were included in the final analysis. In our primary analysis, OFA was non-inferior to OCR in terms of relapses, disability progression, and accrual of MRI lesions. Subgroup analyses confirmed findings in previously naïve and platform-treated patients. Potential differences between OFA and OCR were seen in patients switching from S1P receptor modulators or natalizumab.

CONCLUSION

We here provide comparative data on the effectiveness of OCR and OFA in patients with active RMS. OFA was non-inferior to OCR in the overall cohort. Potential differences observed in patients switching from S1P receptor modulators or natalizumab require further validation. ANN NEUROL 2025;97:583-595.

The role of Epstein-Barr virus in autoimmune and autoinflammatory diseases

Epstein-Barr Virus (EBV), a dsDNA herpesvirus, is believed to play a significant role in exacerbating and potentially triggering autoimmune and autoinflammatory maladies. Around 90% of the world is infected with the virus, which establishes latency within lymphocytes. EBV is also known to cause infectious mononucleosis, a self-limited flu-like illness, in adolescents. EBV is often reactivated and it employs several mechanisms of evading the host immune system. It has also been implicated in inducing host immune dysfunction potentially resulting in exacerbation or triggering of inflammatory processes. EBV has therefore been linked to a number of autoimmune diseases, including systemic lupus erythematosus, multiple sclerosis, rheumatoid arthritis, and Sjögren's syndrome. The review examines the molecular mechanisms through which the virus alters host immune system components thus possibly resulting in autoimmune processes. Understanding the mechanisms underpinning EBV-associated autoimmunity is pivotal; however, the precise causal pathways remain elusive. Research on therapeutic agents and vaccines for EBV has been stagnant for a long number of years until recent advances shed light on potential therapeutic targets. The implications of EBV in autoimmunity underscore the importance of developing targeted therapeutic strategies and, potentially, vaccines to mitigate the autoimmune burden associated with this ubiquitous virus.

Optimizing Drug Selection in Children with Multiple Sclerosis: What Do We Know and What Remains Unanswered?

Pediatric-onset multiple sclerosis (POMS) refers to multiple sclerosis with onset before 18 years of age. It is characterized by a more inflammatory course, more frequent clinical relapses, and a greater number of magnetic resonance imaging (MRI) lesions compared with adult-onset MS (AOMS), leading to significant impacts on both disability progression and cognitive outcomes in affected individuals. Managing POMS presents distinct challenges due to the unique needs of pediatric patients and the limited number of disease-modifying therapies (DMTs) approved for pediatric use. Notably, only one therapy (fingolimod) is approved by the United States (US) Food and Drug Administration (FDA) and three (fingolimod, teriflunomide, and dimethyl fumarate) by the European Medicines Agency (EMA) for use in youth with MS. However, observational evidence identifies use of almost all agents off-label in this population. This review provides a comprehensive overview of literature supporting the use of DMTs for POMS, including evidence from observational studies. In this paper, we highlight the shift in clinical practice, which has led to increased use of high-efficacy therapies (HETs) at or near disease onset. We review emerging evidence indicating better cognitive and motor outcomes in this population with early initiation of therapy. Finally, in this paper, we provide a suggested treatment algorithm for managing POMS. We underscore the need for personalized approaches in POMS management. We identify special considerations unique to pediatric care, including attention to family dynamics, and strategies to improve medication adherence and a smooth transition to adult care. Further research on DMTs in POMS is essential to optimize outcomes and improve long-term prognosis.

The epidemiology, pathology and pathogenesis of MS: Therapeutic implications

Multiple sclerosis (MS) is a chronic, and potentially disabling, inflammatory disease of the central nervous system (CNS). MS is generally characterized by recurrent, and self-limited, episodes of neurological dysfunction, which occur unpredictably and often result in multifocal tissue injury within the CNS. Currently, women are affected two to three times as often as men although this may not have been the case during earlier Time-Periods. The pathogenesis of MS is known to involve both critical genetic and environmental mechanisms. Nevertheless, in addition to these two mechanisms, disease-pathogenesis also involves a "truly" random event. Indeed, it is this random mechanism, which is responsible for the currently-observed (and increasing) excess of women among patients with MS. This review summarizes the current state of knowledge regarding the pathogenesis of MS (includong its epidemiology, pathology, and genetics) and considers the therapeutic implications that these pathogenetic mechanisms have both for our currently available therapies as well as for the possible therapeutic approaches to the management of this potentially disabling condition in the future.

Extended-interval dosing of rituximab/ocrelizumab is associated with a reduced decrease in IgG levels in multiple sclerosis

The potential benefits of extended-interval dosing (EID) of rituximab (RTX) or ocrelizumab (OCR) in mitigating the reduction of immunoglobulin levels and decreasing the risk of infection in persons with relapsing-remitting multiple sclerosis (pwRRMS) remain largely unknown. We retrospectively analyzed two structured data collections including pwRRMS who were prescribed RTX/OCR using different interval dosing regimens, a 6-month standard-interval dosing (SD) or EID. The SD and EID cohorts included 88 and 271 pwRRMS, respectively, with a mean (SD) treatment duration of 3.5 (1.3) and 4.4 (1.5) years, and a mean (SD) interval between infusions of 6.4 (1.7) and 19.2 (11.9) months. After RTX/OCR initiation, the two cohorts did not differ in time to first relapse (p ​= ​0.83), time to first sustained accumulation of disability (p ​= ​0.98) and incidence of MRI activity (p ​= ​0.91). The time to first severe infectious event (SIE) was shorter in the SD cohort (p ​= ​0.005). The effect of treatment duration on reduction of serum IgG level was lower in the EID cohort (Estimate ​= ​0.15 ​g/L per year of follow-up, 95 ​% CI -0.06, -0.23, p ​= ​0.001). In the entire patient group, higher serum IgG levels at the last infusion were associated with a lower risk of SIE between two visits (HR ​= ​0.77 per g/L of serum IgG; 95 ​% CI: 0.66-0.91; p ​= ​0.006). This study suggests that EID of RTX/OCR may reduce the risk of serum IgG decline in pwRRMS without a loss of efficacy and may mitigate the risk of severe infections. These results must be confirmed by future randomized studies.

Elevated frequencies of activated memory B cells in multiple sclerosis are reset to healthy control levels after B cell depletion with Ocrelizumab

In multiple sclerosis (MS) the B cell depleting drug ocrelizumab has shown high efficacy in reducing inflammatory activity. Its mechanism of action is unclear due to B cell subset complexity and unknown roles in pathogenesis. Here, we comprehensively phenotyped and quantitated peripheral blood B cell subsets before and after ocrelizumab infusion to gain insight into the fate of B cell subsets with pathogenic potential. Peripheral blood B cells were collected from treatment naïve patients at baseline and months one, three, and six following the first course of ocrelizumab treatment; at 6 months following the second treatment cycle; ∼14 months following their last infusion; and from healthy controls. Flow cytometry combined with cluster analysis was used to track depletion and repletion of naïve, memory, and antibody secreting cells. By month one, naïve B cells were depleted, but a small subset of memory B cells were retained with no depletion of antibody secreting cells. Uniform manifold approximation and projection for dimension reduction analysis of flow cytometry data revealed two non-class switched naïve clusters and two class switched memory clusters. One class switched cluster was activated in MS patients but largely absent in healthy controls. Both memory B cell subsets underwent depletion after a single six-month course of ocrelizumab treatment after which their proportions were reset to heathy control levels. These observations suggest that activated class-switched memory B cells could serve as a biomarker of recent or ongoing MS disease activity to guide redosing.

Toward curing neurological autoimmune disorders: Biomarkers, immunological mechanisms, and therapeutic targets

Autoimmune neurology is a rapidly expanding field driven by the discovery of neuroglial autoantibodies and encompassing a myriad of conditions affecting every level of the nervous system. Traditionally, autoantibodies targeting intracellular antigens are considered markers of T cell-mediated cytotoxicity, while those targeting extracellular antigens are viewed as pathogenic drivers of disease. However, recent advances highlight complex interactions between these immune mechanisms, suggesting a continuum of immunopathogenesis. The breakdown of immune tolerance, central to these conditions, is affected by modifiable and non-modifiable risk factors such as genetic predisposition, infections, and malignancy. While significant therapeutic advancements have revolutionized treatment of certain diseases, such as neuromyelitis optica, our understanding of many others, particularly T cell-mediated conditions, remains limited, with fewer treatment options available. Future research should focus on improving effector function modeling and deepening our understanding of the factors influencing immune tolerance, with the goal of providing novel treatment options and improving patient care.

Recent advances in mesenchymal stem cell therapy for multiple sclerosis: clinical applications and challenges

Multiple sclerosis (MS), a chronic autoimmune disorder of the central nervous system (CNS), is characterized by inflammation, demyelination, and neurodegeneration, leading to diverse clinical manifestations such as fatigue, sensory impairment, and cognitive dysfunction. Current pharmacological treatments primarily target immune modulation but fail to arrest disease progression or entirely reverse CNS damage. Mesenchymal stem cell (MSC) therapy offers a promising alternative, leveraging its immunomodulatory, neuroprotective, and regenerative capabilities. This review provides an in-depth analysis of MSC mechanisms of action, including immune system regulation, promotion of remyelination, and neuroregeneration. It examines preclinical studies and clinical trials evaluating the efficacy, safety, and limitations of MSC therapy in various MS phenotypes. Special attention is given to challenges such as delivery routes, dosing regimens, and integrating MSCs with conventional therapies. By highlighting advancements and ongoing challenges, this review underscores the potential of MSCs to revolutionize MS treatment, paving the way for personalized and combinatory therapeutic approaches.

Antigen-specific immunotherapies for autoimmune disease

Antigen-specific therapies have a long history in the treatment of allergy but have not been successful in autoimmunity. However, in the past 20 years, advances in the definition of the self-antigens that promote autoimmunity and the growing understanding of the mechanisms that maintain tolerance in health but fail in autoimmunity have led to antigen-specific approaches being considered for the treatment of autoimmune diseases. The core goal of each antigen-specific treatment approach is to remove the immune response that promotes autoimmunity whilst sparing protective responses. Approaches to antigen-specific therapy range from targeted deletion of autoreactive lymphocytes to tolerization of autoreactive T cells and active inhibition of autoimmune responses. Technologies such as vaccines, nanoparticles, cell-based therapies and gene editing are being harnessed to achieve these goals. Remaining challenges include the selection of the best antigen to target, modality and timing of administration of these therapies and the disease in which the therapies are used; overcoming these challenges will be vital to move antigen-specific therapies forward. Once established, antigen-specific therapy has the potential to be applied broadly in the area of autoimmunity.

Targeted Therapies: The Role of Monoclonal Antibodies in Disease Management

Monoclonal antibodies (mAbs) are a key class of biotherapeutic medicines used to treat a wide range of diseases, such as cancer, infectious diseases, autoimmune disorders, cardiovascular diseases, and hemophilia. They can be engineered for greater effectiveness and specific applications while maintaining their structural elements for immune targeting. Traditional immunoglobulin treatments have limited therapeutic uses and various adverse effects. That makes mAbs show rapid growth in the pharmaceutical market, with over 250 mAbs in clinical studies. Although mAbs offer higher specificity, they are less effective against complex antigens. They have become essential in treating diseases with limited medical options, providing innovative solutions that improve patients' quality of life through increasing survival rates, shortening the length of stay in hospitals with an improved treatment outcome, and reducing side effects. This review outlines the mechanisms, applications, and advancements of mAbs, highlighting their transformative role in modern medicine and their potential to shape future therapeutic interventions.

Comparison of B-cell depletion versus natalizumab for treatment of multiple sclerosis: A semi-supervised causal analysis

Background

B-cell depletion (BCD) therapies ( e.g., ocrelizumab, ofatumumab, rituximab) and natalizumab (NTZ) are highly effective disease-modifying therapies (DMTs) for multiple sclerosis (MS). However, no randomized clinical trial and only limited observational studies compared the two DMT classes.

Objective

We compared BCD and NTZ in managing MS patient-reported disability progression using registry-linked electronic healthcare record (EHR) data.

Methods

The study population of an EHR cohort of MS patients included a subset enrolled in a clinic-based MS registry that provided gold-standard outcome labels. To estimate average treatment effects, we applied a doubly-robust semi-supervised approach to analyze all (not only registry) patients and comprehensively adjusted for confounders that included not only a priori standard features but also knowledge graph-derived EHR features. While gold-standard disability outcomes were available in registry patients, we imputed the baseline pre-treatment and post-treatment disability status for non-registry patients. We categorized patient-reported disability progression status as "sustained worsening", "sustained improvement", or "no sustained change" based on 3 or more observations or imputations of Patient Determined Disease Steps (PDDS) scores within 3 years after target treatment initiation as the primary endpoint.

Results

In this MS cohort (n=1,738, Age=46±13 years, Non-Hispanic White=86.71%), there was no significant difference between BCD (n=1,245, 71.63%) and NTZ (n=495, 28.37%) in mitigating sustained worsening (ATE=0.012, 95% CI [-0.123, 0.102], p=.803) or promoting sustained improvement (ATE=-0.0823, 95% CI [-0.194, 0.022], p=.172) of patient-reported disability. Sensitivity analyses using a 2-year window after treatment initiation confirmed no difference in sustained worsening (ATE=-0.0141, 95% CI [-0.107, 0.080], p=.895) or sustained improvement (ATE=-0.0713, 95% CI [-0.263, 0.026], p=.245) between BCD and NTZ. In power analysis, the semi-supervised approach increased statistical power compared to the standard approach of using gold-standard data alone.

Conclusion

This real-world comparative effectiveness analysis based on a novel doubly- robust semi-supervised approach found no difference between BCD and NTZ in managing MS disability progression.

Key Messages

The scarcity of patient-reported disability outcomes in routine clinical care hinders analysis based on real-world patient-reported outcomes, while evaluation of sustained disability accumulation requires long-term follow-up in clinical trials.Using a large registry-linked electronic healthcare record cohort and a novel semi- supervised, doubly-robust method, we conducted a causal inference study to compare sustained change in patient-reported disability in people with MS.The semi-supervised approach effectively leverages additional data from patients without observed outcome information and increases the statistical power of the comparative effectiveness study while retaining robustness properties in the causal analysis.There was no statistically significant difference between B-cell depletion therapy and natalizumab in sustained patient-reported disability outcomes up to 3-years after treatment initiation.

Multiple sclerosis and infection: history, EBV, and the search for mechanism

SUMMARYInfection has long been hypothesized as the cause of multiple sclerosis (MS), and recent evidence for Epstein-Barr virus (EBV) as the trigger of MS is clear and compelling. This clarity contrasts with yet uncertain viral mechanisms and their relation to MS neuroinflammation and demyelination. As long as this disparity persists, it will invigorate virologists, molecular biologists, immunologists, and clinicians to ascertain how EBV potentiates MS onset, and possibly the disease's chronic activity and progression. Such efforts should take advantage of the diverse body of basic and clinical research conducted over nearly two centuries since the first clinical descriptions of MS plaques. Defining the contribution of EBV to the complex and multifactorial pathology of MS will also require suitable experimental models and techniques. Such efforts will broaden our understanding of virus-driven neuroinflammation and specifically inform the development of EBV-targeted therapies for MS management and, ultimately, prevention.

Intrathecal Immunoglobulin A Synthesis in Multiple Sclerosis: From Biological Aspects to Clinical Relevance

Intrathecal immunoglobulin A (IgA) synthesis in multiple sclerosis (MS) has long earned little attention, despite a potential significance in disease pathogenesis and prognosis. The presence of IgA-positive plasma cells in MS lesions and along damaged axons suggests a role in disease pathogenesis. Available clinical evidence about a potential positive or negative prognostic role is scarce and inconclusive. Recent observations, however, highlight the migration of immune regulatory IgA-producing plasma cells from the gut to the central nervous system (CNS) in experimental autoimmune encephalitis models. A connection between intrathecal IgA synthesis and the gut-brain axis in MS was further corroborated by the discovery of gut microbiota-specific IgA+ B cells in human CNS during relapse. In this review, we summarize current evidence on the occurrence and immunopathology of intrathecal IgA synthesis in MS, explore its biological implications, and address methodological challenges regarding the detection of IgA as a major limitation and possible source of inconsistencies in clinical studies. By synthesizing these diverse lines of evidence, we highlight the importance of further research and the need for standardized detection methods to clarify the role of IgA in MS pathogenesis, disease progression, and as potential biomarker.

Clinical and analytical monitoring of patients with multiple sclerosis on anti-CD20 therapeutics: a real-world safety profile study

Background

Anti-CD20 monoclonal antibodies are a class of immunosuppressive drugs widely used in the treatment of central nervous system (CNS) inflammatory diseases, with well-established efficacy and safety. Although rare, these therapies can be associated with serious adverse events including hematological and infectious complications. This study aims to evaluate their safety and tolerability profile in real-world clinical practice.

Methods

We conducted a retrospective cohort study comprising patients diagnosed with multiple sclerosis (MS) treated with anti-CD20 drugs since 2016 followed in the Demyelinating Diseases clinic of a tertiary center. Clinical and paraclinical parameters were evaluated, including complete blood count and immunoglobulins measurements.

Results

A total of 160 with multiple sclerosis (pwMS) were included in our study, of whom 110 (68.8%) were female and 147 are currently receiving anti-CD20 therapies. Half of the patients were diagnosed with relapsing-remitting MS, while the remaining had progressive forms, including 23 with primary-progressive MS and 57 with secondary-progressive MS. Eighty-three patients were on ocrelizumab, 48 on rituximab, and 29 on ofatumumab. The mean follow-up duration from the start of anti-CD20 therapy was 30.5 ± 21.3 months. During this period, serious adverse events were observed in 9 patients, including SARS-CoV-2 infection (resulting in one death), urinary tract infection, febrile neutropenia, severe diarrhea, and acute hepatitis. The rate of serious infections in the ocrelizumab subgroup was consistent with the literature, although a higher rate was observed in the rituximab subgroup. A positive correlation was found between serious infectious complications and lower IgG levels. Additionally, longer exposure to anti-CD20 therapy in our cohort was associated with an increased risk of IgG deficiency and a higher incidence of serious infections. Lymphopenia was detected in 25 patients, though it was not directly linked to the occurrence of serious infections.

Conclusion

Our work confirms the tolerability and safety of anti-CD20 drugs in a real-world clinical practice MS cohort, despite their frequent association with analytical changes such as lymphopenia and hypogammaglobulinemia. To better understand the clinical significance of hypogammaglobulinemia secondary to anti-CD20 treatment and to develop strategies for mitigating the associated potential infection risk, future studies with larger populations are essential.

Curcumin ameliorates astrocyte inflammation through AXL in cuprizone-induced mice

Curcumin has gained global attention owning to its anti-inflammatory, antioxidant, anticancer, and antimicrobial activities. Curcumin has recently been shown to have well-documented effects on neuroinflammation in multiple sclerosis (MS). Astrocytes, the most widely distributed glial cells in the brain, have a significant influence on the regulation of neuroinflammation in MS. However, it is unknown how curcumin exerts neuroprotective effects in astrocytes. To elucidate the mechanism underlying the effects of curcumin on astrocytes, we explored the effect of curcumin on cuprizone (CPZ)-induced mice in vivo and on primary astrocytes in vitro. In this study, we observed that curcumin significantly ameliorated myelin loss and reduced astrocyte activation in the corpus callosum (CC) region in mice induced with CPZ, and in primary astrocytes stimulated with lipopolysaccharide (LPS). Meanwhile, our research indicated that curcumin may exert neuroprotective effects in CPZ-induced mice by downregulating astrocyte-mediated inflammation by AXL. This study provides new insights into possible targeted therapies for MS.

Effect of Different Treatments on Retinal Thickness Changes in Patients With Multiple Sclerosis: A Review

BACKGROUND

Multiple sclerosis (MS) is an autoimmune disorder affecting the central nervous system, with varying clinical manifestations such as optic neuritis, sensory disturbances, and brainstem syndromes. Disease progression is monitored through methods like MRI scans, disability scales, and optical coherence tomography (OCT), which can detect retinal thinning, even in the absence of optic neuritis. MS progression involves neurodegeneration, particularly trans-synaptic degeneration, which extends beyond the initial injury site. This review focuses on the impact of different MS treatments on retinal thickness as assessed by OCT.

RESULTS

Injectable drugs, such as interferon beta and glatiramer acetate (GA), have a relatively modest impact on retinal atrophy. Oral medications like Fingolimod, Teriflunomide, and Dimethyl fumarate also have different impacts on retinal thickness. Fingolimod has been shown to protect against retinal thinning but may lead to macular edema. DMF-treated patients had less ganglion cell-inner plexiform layer thinning than GA-treated patients but more thinning compared to natalizumab-treated patients and healthy controls. Teriflunomide's impact on retinal layers remains unexplored in human studies. Monoclonal antibodies, including Alemtuzumab, Rituximab, Ocrelizumab, and Natalizumab, had protective effects on retinal layer atrophy. Alemtuzumab-treated patients showed significantly less atrophy compared to interferon- and GA-treated patients. Rituximab initially increased atrophy rates in the first months but subsequently demonstrated potential neuroprotective effects. Ocrelizumab slowed the rate of inner nuclear layer thinning in progressive forms of the disease. Natalizumab is considered the most effective in reducing retinal layer atrophy, particularly the peripapillary retinal nerve fiber layer.

CONCLUSIONS

It's important to note that the effectiveness of these treatments may vary depending on MS subtype and individual factors. Future research should explore the long-term effects of these treatments on retinal layers and their correlations with overall disease progression and disability in MS patients.

The prevalence of cancer in patients with multiple sclerosis (MS) who received rituximab: a systematic review and meta-analysis

OBJECTIVE

To estimate the pooled prevalence of cancer in patients with multiple sclerosis (MS) cases who were under treatment with rituximab.

METHODS

We searched PubMed, Scopus, EMBASE, Web of Science, and google scholar along with gray literature up to April 2021. The search strategy included the MeSH and text words as (("CD20 Antibody" AND Rituximab) OR "Rituximab CD20 Antibody" OR Mabthera OR "IDEC-C2B8 Antibody" OR "IDEC C2B8 Antibody" OR IDEC-C2B8 OR "IDEC C2B8" OR GP2013 OR Rituxan OR rituximab) AND ((Sclerosis AND multiple) OR (sclerosis AND disseminated) OR "disseminated sclerosis" OR "multiple sclerosis" OR "acute fulminating").

RESULTS

The literature search revealed 3577 articles, after deleting duplicates 2066 remained. For the meta-analysis, 22 studies were included. Totally, 15599 patients were enrolled while 133 cancers were detected. The pooled prevalence of cancer in MS patients under treatment with rituximab is 1in 100,000 (I2 = 99.9%, p < 0.001).

CONCLUSION

The results of this systematic review and meta-analysis show that the pooled prevalence of cancer in MS patients who received rituximab is 1 in 100,000 cases.

Sequelae of B-Cell Depleting Therapy: An Immunologist's Perspective

B-cell depleting therapy (BCDT) has revolutionised the treatment of B-cell malignancies and autoimmune diseases by targeting specific B-cell surface antigens, receptors, ligands, and signalling pathways. This narrative review explores the mechanisms, applications, and complications of BCDT, focusing on the therapeutic advancements since the introduction of rituximab in 1997. Various monoclonal antibodies and kinase inhibitors are examined for their roles in depleting B cells through antibody-dependent and independent mechanisms. The off-target effects, such as hypogammaglobulinemia, infections, and cytokine release syndrome, are discussed, emphasising the need for immunologists to identify and help manage these complications. The increasing prevalence of BCDT has necessitated the involvement of clinical immunologists in addressing treatment-associated immunological abnormalities, including persistent hypogammaglobulinemia and neutropenia. We highlight the importance of considering underlying inborn errors of immunity (IEI) in patients presenting with these complications. Furthermore, we discuss the impact of BCDT on other immune cell populations and the challenges in predicting and managing long-term immunological sequelae. The potential for novel BCDT agents targeting the BAFF/APRIL-TACI/BCMA axis and B-cell receptor signalling pathways to treat autoimmune disorders is also explored, underscoring the rapidly evolving landscape of B-cell targeted therapies.

Treatment persistence and clinical outcomes in patients starting B cell depleting therapies within the Swiss MS Cohort

Background

Persistence to B cell depleting therapies (BCDT) like ocrelizumab and rituximab may be higher compared with other disease-modifying therapies (DMT) in multiple sclerosis (MS). Clinical trials directly comparing these treatments are lacking.

Objective

To compare the risk of treatment discontinuation, relapse, and confirmed disability worsening in patients starting BCDT vs other DMT within real-world settings.

Methods

In a longitudinal cohort study, patients with relapsing MS starting BCDT (ocrelizumab/rituximab, n = 269) after enrolment into the Swiss MS Cohort (SMSC) were evaluated for treatment discontinuation, occurrence of relapses, and disability worsening in comparison with platform (n = 57) and oral (n = 454) DMT, or natalizumab (n = 73) using Cox regression with double robust adjustment for baseline covariates.

Results

Patients starting BCDT were less likely to discontinue treatment than all other DMT combined (HR = 0.26, 95% CI = 0.18-0.36, p < .01), oral DMT (HR = 0.28, 95% CI = 0.20-0.39, p < .01) and natalizumab (HR = 0.35, 95% CI = 0.21-0.58, p < .01). BCDT were associated with lower risk of relapses as compared to oral DMT HR = 0.59, 95% CI = 0.39-0.88, p < .01), but not to natalizumab (HR = 0.90, 95% CI = 0.45-1.82, p = .778). Disability worsening was not significantly different between treatment groups.

Conclusion

We provide real-world evidence for patients being more persistent to BCDT than to other treatments, and better clinical outcomes may partly explain this.

EBV-specific T-cell immunity: relevance for multiple sclerosis

Genetic and environmental factors jointly determine the susceptibility to develop multiple sclerosis (MS). Improvements in the design of epidemiological studies have helped to identify consistent environmental risk associations such as the increased susceptibility for MS following Epstein-Barr virus (EBV) infection, while biological mechanisms that drive the association between EBV and MS remain incompletely understood. An increased and broadened repertoire of antibody and T-cell immune responses to EBV-encoded antigens, especially to the dominant CD4+ T-cell EBV nuclear antigen 1 (EBNA1), is consistently observed in patients with MS, indicating that protective EBV-specific immune responses are deregulated in MS and potentially contribute to disease development. Exploitation of B-cell trajectories by EBV infection might promote survival of autoreactive B-cell species and proinflammatory B:T-cell interactions. In this review article, we illustrate evidence for a causal role of EBV infection in MS, discuss how EBV-targeting adaptive immune responses potentially modulate disease susceptibility and progression, and provide future perspectives on how novel model systems could be utilized to better define the role of EBV and viral pathogens in MS. Insights gained from these studies might facilitate the development of prevention strategies and more effective treatments for MS.

Anti-CD20 monoclonal antibodies in multiple sclerosis: Rethinking the current treatment strategy

Anti-CD20 monoclonal antibodies are highly-effective B-cell-depleting therapies in multiple sclerosis (MS). These treatments have expanded the arsenal of highly effective disease-modifying therapies, and have changed the landscape in understanding the pathophysiology of MS and the natural course of the disease. Nevertheless, these treatments come at the cost of immunosuppression and risk of serious infections, diminished vaccination response and treatment-related secondary hypogammaglobulinemia. However, the COVID pandemic has given way to a possibility of readapting these therapies, with most notably extended dosing intervals. While these new strategies show efficacy in maintaining inflammatory MS disease control, and although it is tempting to speculate that tailoring CD20 therapies will reduce the negative outcomes of long-term immunosuppression, it is unknown whether they provide meaningful benefit in reducing the risk of treatment-related secondary hypogammaglobulinemia and serious infections. This review highlights the available anti-CD20 therapies that are available for treating MS patients, and sheds light on encouraging data, which propose that tailoring anti-CD20 monoclonal antibodies is the next step in rethinking the current treatment strategy.

Global perspectives on the contribution of B cells to multiple sclerosis: an in-depth examination and evaluation

Background

Multiple sclerosis (MS) is a chronic, progressive autoimmune disease, with increasing attention on the role of B cells in its pathogenesis. Despite this growing interest, a comprehensive analysis of research trends and emerging foci on B cells in MS is currently lacking. In this research, we utilize a bibliometric approach to visualize and analyze research trends and focal points in this field, offering a valuable reference for future mechanistic studies in MS.

Methods

We retrieved bibliometric data from the Web of Science Core Collection (WOSCC) for articles published between 2014 and 2023. VOSviewer 1.6.18 and CiteSpace 5.7R3 were used for co-authorship, co-occurrence, and citation analyses to identify key researchers, institutions, countries, and emerging themes in B cell research related to MS.

Results

The analysis examined 5,578 articles published in 1,041 journals by 5,337 institutions globally. The United States leads in publication output, with Amit Bar-Or identified as the most influential author, and Frontiers in Immunology as the top journal in the field. Research has increasingly focused on the complex role of B cells in MS, particularly their involvement in the central nervous system (CNS) and mechanisms of anti-B cell therapy. Recent trends point to a growing focus on meningeal inflammation, kinase inhibitors, and Epstein-Barr virus, signaling a shift in research priorities.

Conclusion

This bibliometric analysis highlights pivotal research trends, key contributors, and emerging areas of interest in B cell research in MS from 2013 to 2024. The findings underscore the growing recognition of the multifaceted role of B cells in MS pathogenesis, particularly their involvement in the CNS compartment and the potential of targeted therapies. The study identifies meningeal inflammation, Epstein-Barr virus infection, and kinase inhibitors as promising avenues for future research. The analyses driving the in-depth exploration of B cell mechanisms in MS and the development of novel diagnostic and therapeutic strategies provide researchers in the MS field with a comprehensive and objective perspective, serving as a valuable reference for accelerating the translation of basic research findings into clinical applications.

Neddylation of protein, a new strategy of protein post-translational modification for targeted treatment of central nervous system diseases

Neddylation, a type of protein post-translational modification that links the ubiquitin-like protein NEDD8 to substrate proteins, can be involved in various significant cellular processes and generate multiple biological effects. Currently, the best-characterized substrates of neddylation are the Cullin protein family, which is the core subunit of the Cullin-RING E3 ubiquitin ligase complex and controls many important biological processes by promoting ubiquitination and subsequent degradation of various key regulatory proteins. The normal or abnormal process of protein neddylation in the central nervous system can lead to a series of occurrences of normal functions and the development of diseases, providing an attractive, reasonable, and effective targeted therapeutic strategy. Therefore, this study reviews the phenomenon of neddylation in the central nervous system and summarizes the corresponding substrates. Finally, we provide a detailed description of neddylation involved in CNS diseases and treatment methods that may be used to regulate neddylation for the treatment of related diseases.

Towards Treating Multiple Sclerosis Progression

Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system (CNS). In most patients, the disease starts with an acute onset followed by a remission phase, subsequent relapses and a later transition to steady chronic progression. In a minority of patients, this progressive phase develops from the beginning. MS relapses are characterized predominantly by the de novo formation of an inflammatory CNS lesion and the infiltration of immune cells, whereas the pathological features of MS progression include slowly expanding lesions, global brain atrophy and an inflammatory response predominantly mediated by macrophages/microglia. Importantly, this CNS-intrinsic pathophysiology appears to initiate early during the relapsing-remitting disease phase, while it turns into the key clinical MS feature in later stages. Currently approved disease-modifying treatments for MS are effective in modulating peripheral immunity by dampening immune cell activity or preventing the migration of immune cells into the CNS, resulting in the prevention of relapses; however, they show limited success in halting MS progression. In this manuscript, we first describe the pathological mechanisms of MS and summarize the approved therapeutics for MS progression. We also review the treatment options for progressive MS (PMS) that are currently under investigation. Finally, we discuss potential targets for novel treatment strategies in PMS.

Anti-CD20 therapies for pediatric-onset multiple sclerosis: A systematic review

BACKGROUND

Pediatric-onset multiple sclerosis (POMS) cases, defined as multiple sclerosis (MS) with onset before the age of 18, represent between 3 and 5 % of all MS patients. Anti-CD20 drugs mainly rituximab, ocrelizumab, and ofatumumab are being widely used in adult-onset MS. Their use in POMS is also being increasingly considered by experts.

OBJECTIVE

to review the latest evidence on safety and efficacy of the use of anti-CD20 therapies in POMS.

METHODS

An extensive search was performed in PubMed, Scopus, and Web of Science databases until the end of July 1st, 2024. Two independent reviewers screened the articles, and collected data. 832 studies were screened using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines.

RESULTS

12 studies on rituximab (328 patients) and 6 studies on ocrelizumab (106 patients) were synthesized. Using monoclonal antibodies in POMS patients has a noteworthy effect on reducing relapses and lesions and achieving no evidence of disease activity especially in highly active POMS patients. However, anti-CD20 therapies in MS are associated with potential adverse events (AEs). Additional data is required on the effect of anti-CD20 therapy on disability accrual.

CONCLUSION

Although anti-CD20 therapy is associated with some AEs, it can be provided in several circumstances, especially to patients with highly active disease, or ones resistant to platform therapies.

A Real-World Experience of Rituximab: A Panacea in Therapy of Multiple Sclerosis in Low- and Middle-Income Settings

BACKGROUND

Anti-CD20 monoclonal antibodies have received increasing attention in the past few years in the treatment of multiple sclerosis (MS).

OBJECTIVES

This study describes the (i) efficacy and safety of rituximab in people living with MS and (ii) assesses clinical and imaging outcomes following rituximab in MS.

METHOD

This is a chart review from the MS registry maintained at the institute from a University Hospital in South India.

RESULT

Eighty-three (M:F, 26:57) people living with MS received rituximab as immunomodulation between 2007 and 2022 with a median follow-up duration of 18 months. Fifty-nine (71%) were classified as relapsing-remitting MS, 16 (19%) were secondary progressive MS, and 8 (10%) were primary progressive MS. Seventy-two (87%) MS patients did not experience any relapse after receiving rituximab. In relapsing-remitting MS patients, the mean annualized recurrence rate dropped from 1.24 ± 1.19 to 0.16 ± 0.37. Infusion-related reaction occurred in 5 (6% of adverse events), urinary infections in 7 (8.4%), systemic infections in 3 (3%), Pneumocystis carinii pneumonia occurred in 1 (1%), and herpes zoster infection in 1 (1%) patient. Mortality was observed in 3 (3.5%) patients. While being on rituximab, 18 (22%) patients had mild COVID-19 illness and they all made complete recovery without any sequalae.

CONCLUSIONS

Rituximab is a safe, well-tolerated, easily accessible, inexpensive, and effective therapeutic option for people with MS. Rituximab showed both clinical and radiological improvement after a median follow-up of 1.5 years. None of our patients showed any severe COVID infection nor side effects after receiving COVID vaccination.

Rapid depletion of CD20+ B and T cells following ofatumumab therapy onset

BACKGROUND

The humanized monoclonal anti-CD20-antibody ofatumumab is highly effective in treating relapsing multiple sclerosis (MS).

OBJECTIVE

This study aimed to investigate the immanent effect of ofatumumab on the peripheral immune system, particularly targeting B and T cells expressing CD20.

METHODS

Blood samples of 53 MS patients receiving ofatumumab were collected prior to first application and after one week, two weeks and three months. Multicolor flow cytometry was used to phenotype peripheral blood mononuclear cells, and immunoglobulin (Ig) concentrations were measured by nephelometry.

RESULTS

Among CD20+ lymphocytes, 13 % co-expressed CD3 (identifying them as CD3+CD20+ T lymphocytes), with a noticeable shift in the CD4/CD8-ratio towards CD8+ T cells. One week after administering ofatumumab, a significant reduction of CD20+ lymphocytes with complete depletion of CD3+CD20+ T lymphocytes was observed, persisting during the investigation period. During the treatment, IgM levels showed a slight but significant decrease, whereas IgA and IgG levels remained stable.

CONCLUSION

Ofatumumab effectively depletes CD20+ lymphocytes already after the first administration. This depletion affects not only B cells, but also a small proportion of T cells (CD3+CD20+), affirming the hypothesis that the anti-inflammatory effects of CD20+ cell depletion might extend to the reduction of CD3+CD20+ T lymphocytes.

High-yield production of recombinant human myelin oligodendrocyte glycoprotein in SHuffle bacteria without a refolding step

Experimental autoimmune encephalomyelitis (EAE) is a model for central nervous system (CNS) autoimmune demyelinating diseases such as multiple sclerosis (MS) and MOG antibody-associated disease (MOGAD). Immunization with the extracellular domain of recombinant human MOG (rhMOG), which contains pathogenic antibody and T cell epitopes, induces B cell-dependent EAE for studies in mice. However, these studies have been hampered by rhMOG availability due to its insolubility when overexpressed in bacterial cells, and the requirement for inefficient denaturation and refolding. Here, we describe a new protocol for the high-yield production of soluble rhMOG in SHuffle cells, a commercially available E. coli strain engineered to facilitate disulfide bond formation in the cytoplasm. SHuffle cells can produce a soluble fraction of rhMOG yielding >100 mg/L. Analytical size exclusion chromatography multi-angle light scattering (SEC-MALS) and differential scanning fluorimetry of purified rhMOG reveals a homogeneous monomer with a high melting temperature, indicative of a well-folded protein. An in vitro proliferation assay establishes that purified rhMOG can be processed and recognized by T cells expressing a T cell receptor (TCR) specific for the immunodominant MOG35-55 peptide epitope. Lastly, immunization of wild-type, but not B cell deficient, mice with rhMOG resulted in robust induction of EAE, indicating a B cell-dependent induction. Our SHuffle cell method greatly simplifies rhMOG production by combining the high yield and speed of bacterial cell expression with enhanced disulfide bond formation and folding, which will enable further investigation of B cell-dependent EAE and expand human research of MOG in CNS demyelinating diseases.

Intrathecal IgG and IgM synthesis correlates with neurodegeneration markers and corresponds to meningeal B cell presence in MS

Intrathecal synthesis of immunoglobulins (Igs) is a key hallmark of multiple sclerosis (MS). B cells are known to accumulate in the leptomeninges of MS patients and associate with pathology in the underlying cortex and a more severe disease course. However, the role of locally produced antibodies in MS brain pathology is poorly understood. Here, we quantified the protein levels of IgA, IgM, IgG and albumin in serum and cerebrospinal fluid (CSF) samples of 80 MS patients and 28 neurological controls to calculate Ig indices. In addition, we quantified presence of meningeal IgA+, IgM+ and IgG+ B cells in post-mortem brain tissue of 20 MS patients and 6 controls using immunostainings. IgM and IgG, but not IgA, indices were increased in CSF of MS patients compared to controls, with no observed differences between MS disease types. Both IgM and IgG indices correlated significantly with neurofilament light (NfL) levels in CSF, but not with clinical or radiological parameters of disease. Similarly, IgG+ and IgM+ B cells were increased in MS meninges compared to controls, whereas IgA+ B cells were not. Neuronal loss did not differ between sections with low or high IgA+, IgM+ and IgG+ B cells, but was increased in sections with high numbers of all CD19+ meningeal B cells. Similarly, high presence of CD19+ meningeal B cells and IgG+ meningeal B cells associated with increased microglial density in the underlying cortex. Taken together, intrathecal synthesis of IgG and IgM is elevated in MS, which corresponds to an increased number of IgG+ and IgM+ B cells in MS meninges. The significant correlation between intrathecal IgG and IgM production and NfL levels, and increased microglial activation in cortical areas adjacent to meningeal infiltrates with high levels of IgG+ B cells indicate a role for intrathecal IgM- and IgG-producing B cells in neuroinflammatory and degenerative processes in MS.

Improvements in no evidence of disease activity with ublituximab vs. teriflunomide in the ULTIMATE phase 3 studies in relapsing multiple sclerosis

Background

Ublituximab is a novel anti-CD20 monoclonal antibody glycoengineered for enhanced antibody-dependent cellular cytotoxicity. The phase 3 ULTIMATE I and II studies showed significant improvements in annualized relapse rate, total number of gadolinium-enhancing (Gd+) T1 lesions, and total number of new or enlarging T2 at Week 96, as well as improvement in the proportion of participants with no evidence of disease activity (NEDA) from Weeks 24-96 with ublituximab vs. teriflunomide.

Methods

In ULTIMATE I (NCT03277261; www.clinicaltrials.gov) (N = 549) and II (NCT03277248; www.clinicaltrials.gov) (N = 545), participants with relapsing multiple sclerosis received ublituximab 450 mg intravenous infusion every 24 weeks (following Day 1 infusion of 150 mg and Day 15 infusion of 450 mg) or teriflunomide 14 mg oral once daily for 96 weeks. Pooled post hoc analyses evaluated NEDA by treatment epoch and participant subtype: age ( ≤ 38 or >38 years), early or later disease (<3 or ≥3 years following diagnosis), treatment history (treatment naïve or previously treated), 0 or ≥1 Gd+ T1 lesions at baseline, and Expanded Disability Status Scale score ≤ 3.5 or >3.5 at baseline. NEDA was defined as no confirmed relapses, no Gd+ T1 lesions, no new or enlarging T2 lesions, and no disability progression confirmed for ≥12 weeks.

Results

NEDA rates in the ublituximab vs. teriflunomide cohorts by treatment epoch were: Weeks 0-96, 44.6% vs. 12.4% (3.6 × improvement); Weeks 24-96 (re-baselined), 82.1% vs. 22.5% (3.6 × improvement); and Weeks 48-96 (re-baselined), 88.2% vs. 30.4% (2.9 × improvement) (all p < 0.0001). The primary driver of disease activity in ublituximab-treated participants was new or enlarging T2 lesions during Weeks 0-24. 41.8% of ublituximab-treated participants who had evidence of disease activity in the first year (Weeks 0-48) experienced NEDA in the second year of treatment (Weeks 48-96) compared with 17.3% of teriflunomide-treated participants. At Weeks 24-96 (re-baselined), rates of NEDA were significantly higher with ublituximab than teriflunomide in all participant subtypes (all p < 0.0001).

Conclusions

ULTIMATE I and II pooled post hoc analyses demonstrated a consistent NEDA benefit among ublituximab-treated participants across treatment epochs and key participant subpopulations.

B-cell depletion in autoimmune diseases

B cells have a pivotal function in the pathogenesis of autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis and systemic lupus erythematosus. In autoimmune disease, B cells orchestrate antigen presentation, cytokine production and autoantibody production, the latter via their differentiation into antibody-secreting plasmablasts and plasma cells. This article addresses the current therapeutic strategies to deplete B cells in order to ameliorate or potentially even cure autoimmune disease. It addresses the main target antigens in the B-cell lineage that are used for therapeutic approaches. Furthermore, it summarises the current evidence for successful treatment of autoimmune disease with monoclonal antibodies targeting B cells and the limitations and challenges of these approaches. Finally, the concept of deep B-cell depletion and immunological reset by chimeric antigen receptor T cells is discussed, as well as the lessons from this approach for better understanding the role of B cells in autoimmune disease.

Glatiramer Acetate for the Treatment of Multiple Sclerosis: From First-Generation Therapy to Elucidation of Immunomodulation and Repair

Multiple sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system (CNS), with a putative autoimmune origin and complex pathogenesis. Modification of the natural history of MS by reducing relapses and slowing disability accumulation was first attained in the 1990 s with the development of the first-generation disease-modifying therapies. Glatiramer acetate (GA), a copolymer of L-alanine, L-lysine, L-glutamic acid, and L-tyrosine, was discovered due to its ability to suppress the animal model of MS, experimental autoimmune encephalomyelitis. Extensive clinical trials and long-term assessments established the efficacy and the safety of GA. Furthermore, studies of the therapeutic processes induced by GA in animal models and in MS patients indicate that GA affects various levels of the innate and the adaptive immune response, generating deviation from proinflammatory to anti-inflammatory pathways. This includes competition for binding to antigen presenting cells; driving dendritic cells, monocytes, and B-cells toward anti-inflammatory responses; and stimulating T-helper 2 and T-regulatory cells. The immune cells stimulated by GA reach the CNS and secrete in situ anti-inflammatory cytokines alleviating the pathological processes. Furthermore, cumulative findings reveal that in addition to its immunomodulatory effect, GA promotes neuroprotective repair processes such as neurotrophic factors secretion, remyelination, and neurogenesis. This review aims to provide an overview of MS pathology diagnosis and treatment as well as the diverse mechanism of action of GA. SIGNIFICANCE STATEMENT: Understanding the complex MS immune pathogenesis provided multiple targets for therapeutic intervention, resulting in a plethora of agents, with various mechanisms of action, efficacy, and safety profiles. However, promoting repair beyond the body's limited spontaneous extent is still a major challenge. GA, one of the first approved disease-modifying therapies, induces diverse immunomodulatory effects. Furthermore, GA treatment results in elevated neurotrophic factors secretion, remyelination and neurogenesis, supporting the notion that immunomodulatory treatment can support in situ a growth-promoting and repair environment.

An overview on disease modifying and symptomatic drug treatments for multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is an inflammatory and degenerative autoimmune condition, resulting frequently in a disabling condition. Significant improvements of long-term prognosis have been recently achieved with an early and more aggressive use of disease modifying therapies (DMTs). Addressing the complexity of managing its progressive forms remains a significant challenge.

AREAS COVERED

This review provides an update on DMTs for relapsing-remitting MS (RRMS) and progressive MS and their efficacy, safety, and mechanism of action, emphasizing the critical role of biomarkers in optimizing treatment decisions. Moreover, some key information on drugs used to manage symptoms such as pain, fatigue, spasticity and urinary problems will be provided. The literature search was conducted using PubMed, Embase, and Cochrane Library databases covering the period from January 2000 to January 2024.

EXPERT OPINION

Major advances have been achieved in the treatment of RRMS. Treatment should start immediately as soon as the neurologist is confident with the diagnosis and its choice should be based on the prognostic profile and on the patient's propensity to accept drug-related risks. The therapeutic landscape for progressive MS is quite disappointing and necessitates further innovation. Personalized medicine, leveraging biomarker insights, holds promise for refining treatment efficacy and patient outcomes.

TIM-4 Identifies Effector B Cells Expressing a RORγt-Driven Proinflammatory Cytokine Module That Promotes Immune Responsiveness

B cells can express pro-inflammatory cytokines that promote a wide variety of immune responses. Here we show that B cells expressing the phosphatidylserine receptor TIM-4, preferentially express IL-17A, as well as IL-22, IL-6, IL-1β, and GM-CSF - a collection of cytokines reminiscent of pathogenic Th17 cells. Expression of this proinflammatory module requires IL-23R signaling and selective expression of RORγt and IL-17A by TIM-4+ B cells. TIM-4+ B cell-derived-IL-17A not only enhances the severity of experimental autoimmune encephalomyelitis (EAE) and promotes allograft rejection, but also acts in an autocrine manner to prevent their conversion into IL-10-expressing B cells with regulatory function. Thus, IL-17A acts as an inflammatory mediator and also enforces the proinflammatory activity of TIM-4+ B cells. Thus, TIM-4 serves as a broad marker for RORγt+ effector B cells (Beff) and allows further study of the signals regulating Beff differentiation and effector molecule expression.

Longitudinal analysis of peripheral immune cells in patients with multiple sclerosis treated with anti-CD20 therapy

OBJECTIVE

Anti-CD20 therapy is a highly effective treatment for multiple sclerosis (MS). In this study, we investigated MS-related changes in peripheral blood mononuclear cell (PBMC) subsets compared to healthy controls and longitudinal changes related to the treatment.

METHODS

Multicolor spectral flow cytometry analysis was performed on 78 samples to characterize disease- and treatment-related PBMC clusters. Blood samples from MS patients were collected at baseline and up to 8 months post-treatment, with three collection points after treatment initiation. Unsupervised clustering tools and manual gating were applied to identify subclusters of interest and quantify changes.

RESULTS

B cells were depleted from the periphery after anti-CD20 treatment as expected, and we observed an isolated acute, transitory drop in the proportion of natural killer (NK) and NKT cells among the main populations of PBMC (P = 0.03, P = 0.004). Major affected PBMC subpopulations were cytotoxic immune cells (NK, NKT, and CD8+ T cells), and we observed a higher proportion of cytotoxic cells with reduced brain-homing ability and a higher regulatory function as a long-term anti-CD20-related effect. Additionally, anti-CD20 therapy altered distributions of memory CD8+ T cells and reduced exhaustion markers in both CD4+ and CD8+ T cells.

INTERPRETATION

The findings of this study elucidate phenotypic clusters of NK and CD8+ T cells, which have previously been underexplored in the context of anti-CD20 therapy. Phenotypic modifications towards a more regulatory and controlled phenotype suggest that these subpopulations may play a critical and previously unrecognized role in mediating the therapeutic efficacy of anti-CD20 treatments.

B-cell Depletion Therapy in Pediatric Neuroinflammatory Disease

PURPOSE OF REVIEW

B-cell depletion therapy, including anti-CD20 and anti-CD19 therapies, is increasingly used for a variety of autoimmune and conditions, including those affecting the central nervous system. However, B-cell depletion therapy use can be complicated by adverse effects associated with administration and immunosuppression. This review aims to summarize the application of anti-CD20 and anti-CD19 therapies for the pediatric neurologist and neuroimmunologist.

RECENT FINDINGS

Most existing literature come from clinical trials with adult patients, although more recent studies are now capturing the effects of these therapies in children. The most common side effects include infusion related reactions and increased infection risk from immunosuppression. Several strategies can mitigate infusion related reactions. Increased infections due to persistent hypogammaglobulinemia can benefit from replacement immunoglobulin. B-cell depletion therapies can be safe and effective in pediatric patients. Anticipation and mitigation of common adverse effects through primary prevention strategies, close monitoring, and appropriate symptomatic management can improve safety and tolerability.

Chimeric antigen receptor T-cell therapy for autoimmune diseases of the central nervous system: a systematic literature review

IMPORTANCE

B-cell-targeting monoclonal antibodies have demonstrated safety and efficacy in multiple sclerosis or anti-aquaporin-4 IgG positive neuromyelitis optica spectrum disorder. However, these therapies do not facilitate drug-free remission, which may become possible with cell-based therapies, including chimeric antigen receptor (CAR) T cells. CAR T-cell therapy holds promise for addressing other antibody-mediated CNS disorders, e.g., MOG-associated disease or autoimmune encephalitis.

OBJECTIVE

To provide an overview of the current clinical knowledge on CAR T-cell therapy in central nervous system autoimmunity.

EVIDENCE REVIEW

We searched PubMed, Embase, Google Scholar, PsycINFO, and clinicaltrials.gov using the terms 'CAR T cell' and 'multiple sclerosis/MS' or 'neuromyelitis optica/spectrum diseases/NMOSD' or 'MOG-associated disease/MOGAD 'or' autoimmune encephalitis' or 'neuroimmunology'.

FINDINGS

An ongoing phase I clinical trial has indicated the safety and benefits of anti-BCMA CAR T cells in 12 patients with AQP4-IgG seropositive neuromyelitis optica spectrum disorder. Case reports involving two individuals with progressive multiple sclerosis and one patient with stiff-person syndrome demonstrated a manageable safety profile following treatment with anti-CD19 CAR T cells. Recruitment has commenced for two larger studies in MS, and a phase I open-label basket study is underway to evaluate BCMA-directed CAR T cells in various antibody-associated inflammatory diseases, including MOG-associated disease. Preclinical research on NMDA receptor antibody autoimmune encephalitis treated with chimeric autoantibody receptor T cells generated promising data.

CONCLUSIONS AND RELEVANCE

There is minimal evidence of the benefits of CAR T-cell therapy in individuals with central nervous system-directed autoimmunity. Nevertheless, multicenter controlled clinical trials with a manageable safety profile appear feasible and are warranted due to very promising case experiences.

Rituximab in secondary progressive multiple sclerosis: a meta-analysis

OBJECTIVE

To evaluate the efficacy of rituximab (RTX) in stabilizing disability progression in secondary progressive multiple sclerosis (SPMS).

METHODS

A systematic review was conducted, encompassing studies from inception to April 2023, utilizing the MEDLINE and EMBASE databases. Inclusion criteria comprised studies with a minimum of 3 SPMS patients receiving intravenous RTX in at least one infusion, with a follow-up duration of at least 6 months. Primary outcome measures included changes in Expanded Disability Status Scale (EDSS) scores. Mean differences in pre- and post-RTX EDSS scores were analyzed using a random-effects model. Meta-regression examined age at RTX initiation, pre-RTX EDSS scores, disease duration, and outcome reported time as variables. Secondary outcomes assessed changes in the annualized relapse rate (ARR).

RESULTS

Thirteen studies, involving 604 SPMS patients, met the inclusion criteria. Following a mean follow-up of 2 years, the mean difference in EDSS scores (ΔEDSS = EDSSpre-RTX - EDSSpost-RTX) was -0.21 (95% CI -0.51 to 0.08, p = 0.16), indicating no significant variation. Multivariable meta-regression identified significant associations between EDSS score mean difference and pre-RTX EDSS scores, disease duration at RTX initiation, and outcome reported time. However, age at RTX initiation showed no significant association. Pre- and post-RTX ARR data were available for 245 out of 604 SPMS patients across seven studies, revealing a mean difference in ARR (ΔARR = ARRpre-RTX - ARRpost-RTX) of 0.74 (95% CI 0.19-1.29, p = 0.008).

INTERPRETATION

RTX demonstrates efficacy in reducing relapse frequency and exhibits potential in stabilizing disability progression over a 2-year follow-up, particularly among individuals with shorter disease duration.

B cells drive neuropathic pain-related behaviors in mice through IgG-Fc gamma receptor signaling

Neuroimmune interactions are essential for the development of neuropathic pain, yet the contributions of distinct immune cell populations have not been fully unraveled. Here, we demonstrate the critical role of B cells in promoting mechanical hypersensitivity (allodynia) after peripheral nerve injury in male and female mice. Depletion of B cells with a single injection of anti-CD20 monoclonal antibody at the time of injury prevented the development of allodynia. B cell-deficient (muMT) mice were similarly spared from allodynia. Nerve injury was associated with increased immunoglobulin G (IgG) accumulation in ipsilateral lumbar dorsal root ganglia (DRGs) and dorsal spinal cords. IgG was colocalized with sensory neurons and macrophages in DRGs and microglia in spinal cords. IgG also accumulated in DRG samples from human donors with chronic pain, colocalizing with a marker for macrophages and satellite glia. RNA sequencing revealed a B cell population in naive mouse and human DRGs. A B cell transcriptional signature was enriched in DRGs from human donors with neuropathic pain. Passive transfer of IgG from injured mice induced allodynia in injured muMT recipient mice. The pronociceptive effects of IgG are likely mediated through immune complexes interacting with Fc gamma receptors (FcγRs) expressed by sensory neurons, microglia, and macrophages, given that both mechanical allodynia and hyperexcitability of dissociated DRG neurons were abolished in nerve-injured FcγR-deficient mice. Consistently, the pronociceptive effects of IgG passive transfer were lost in FcγR-deficient mice. These data reveal that a B cell-IgG-FcγR axis is required for the development of neuropathic pain in mice.

Three cases with chronic obsessive compulsive disorder report gains in wellbeing and function following rituximab treatment

Immunological aetiology is supported for a subgroup with obsessive compulsive disorder (OCD) and conceptualized as autoimmune OCD. The longitudinal clinical course is detailed for three severely ill cases with OCD and indications of immunological involvement with off-label rituximab treatment every six months. All cases showed clear and sustained gains regarding symptom burden and function for over 2.5 years. Brief Psychiatric Rating Scale and Yale-Brown Obsessive-Compulsive Inventory Scale scores decreased 67-100% and 44-92%, respectively. These complex cases, prior to rituximab, had very low functioning and disease duration has been eight, nine and 16 years respectively. All three patients had been unsuccessfully treated with at least two antidepressants or anxiolytics, one neuroleptic and cognitive behavioural therapy. Clinical phenotypes and findings were suggestive of possible autoimmune OCD. Indirect immunohistochemistry detected cerebral spinal fluid (CSF) antibodies in all three cases including a novel anti-neuronal staining pattern against mouse thalamic cells. Exploratory analyses of CSF markers and proteomics identified elevated levels of sCD27 and markers indicative of complement pathway activation when compared to CSF from healthy controls. Multidisciplinary collaboration, advanced clinical investigations and rituximab treatment are feasible in a psychiatric setting. The case histories provide a proof of principle for the newly proposed criteria for autoimmune OCD. The findings suggest that clinical red flags and biological measures may predict rituximab response in chronic treatment-resistant OCD. The report provides orientation that may inform the hypotheses and design of future treatment trials.

Novel model of multiple sclerosis induced by EBV-like virus generates a unique B cell population

Epstein-Barr virus (EBV) is deemed a necessary, yet insufficient factor in the development of multiple sclerosis (MS). In this study, myelin basic protein-specific transgenic T cell receptor mice were infected with murid gammaherpesvirus 68 virus (MHV68), an EBV-like virus that infects mice, resulting in the onset neurological deficits at a significantly higher frequency than influenza or mock-infected mice. MHV68 infected mice exhibited signs including optic neuritis and ataxia which are frequently observed in MS patients but not in experimental autoimmune encephalomyelitis mice. MHV68-infected mice exhibited increased focal immune cell infiltration in the central nervous system. Single cell RNA sequencing identified the emergence of a population of B cells that express genes associated with antigen presentation and costimulation, indicating that gammaherpesvirus infection drives a distinct, pro-inflammatory transcriptional program in B cells that may promote autoreactive T cell responses in MS.

Drug Repurposing Via the Best Pharmaceuticals for Children Act

This Viewpoint discusses the benefits and impediments of drug repurposing in the US and how the Best Pharmaceuticals for Children Act may serve as a successful legislative model to stimulate greater drug repurposing.

B Cells Influence Encephalitogenic T Cell Frequency to Myelin Oligodendrocyte Glycoprotein (MOG)38-49 during Full-length MOG Protein-Induced Demyelinating Disease

Although T cells are encephalitogenic during demyelinating disease, B cell-depleting therapies are a successful treatment for patients with multiple sclerosis. Murine models of demyelinating disease utilizing myelin epitopes, such as myelin oligodendrocyte glycoprotein (MOG)35-55, induce a robust CD4 T cell response but mitigate the contribution of pathological B cells. This limits their efficacy for investigating how B cell depletion affects T cells. Furthermore, induction of experimental autoimmune encephalomyelitis with a single CD4 T cell epitope does not reflect the breadth of epitopes observed in the clinic. To better model the adaptive immune response, mice were immunized with the full-length MOG protein or the MOG1-125 extracellular domain (ECD) and compared with MOG35-55. Mature MOG-reactive B cells were generated only by full-length MOG or ECD. The CNS-localized T cell response induced by full-length MOG is characterized by a reduction in frequency and the percentage of low-affinity T cells with reactivity toward the core epitope of MOG35-55. B cell depletion with anti-CD20 before full-length MOG-induced, but not ECD-induced, demyelinating disease restored T cell reactivity toward the immunodominant epitope of MOG35-55, suggesting the B cell-mediated control of encephalitogenic epitopes. Ultimately, this study reveals that anti-CD20 treatment can influence T cell epitopes found in the CNS during demyelinating disease.

Quality of life and tolerability of B-cell directed therapy of multiple sclerosis with ofatumumab in a patient-centered real-world observational study

INTRODUCTION

Ofatumumab (Kesimpta®) is a subcutaneous CD20-targeting antibody approved in Germany in 2021 for the treatment of relapsing multiple sclerosis (RMS). After careful instruction, patients can administer the treatment themselves. We previously reported data of 101 patients (Klimas et al. in Nervenarzt 94:923-933, 2023). The objective of this longitudinal study is to explore the tolerability and acceptability of ofatumumab from a patient perspective over a follow up period of 6 months.

METHODS

In this prospective observational real-world study, we report follow up data of 81 patients. We evaluated sociodemographic data, disease duration, duration and side effects of ofatumumab use, expanded disability status scale (EDSS), Beck Depression Inventory II (BDI-II), Short-Form 36 (SF-36), Fatigue Scale of Motor and Cognitive Functions (FSMC), and modified Multiple Sclerosis Functional Composite Test (MSFC). In addition, we asked for subjective treatment outcomes, such as impact on quality of life, walking distance, concentration, mood, medication adherence, fatigue and the subjective course of MS on a numerical rating scale (1 = very negative; 5 = very positive). Furthermore, treatment discontinuations were recorded.

RESULTS

The average duration of ofatumumab treatment was 10 months. In comparison to previous published data of our cohort, patients reported a significant increase in headache (10% up to 26%, p = 0.004) and limb pain (5% up to 26%, p < 0.001) as persistent side effects after the injections. More patients reported a very positive effect (p < 0.0001) on quality of life. 4 confirmed relapses occurred but no EDSS worsening, and no treatment discontinuations were documented during the observation period.

DISCUSSION

As previously described, our prospective study indicates that patients have a good tolerability of ofatumumab, precisely because of the mild and few side effects at the first administration. However, the longer the observation period, the more headaches and limb pain occurred after the injections. Despite this, patients' subjective quality of life improved. There were no discontinuations during the follow-up period, with the limitation of a high loss to follow-up.

Enhanced and cross-reactive in vitro memory B cell response against Epstein-Barr virus nuclear antigen 1 in multiple sclerosis

Multiple sclerosis (MS) is a prototypical autoimmune disease of the central nervous system (CNS). In addition to CD4+ T cells, memory B cells are now recognized as a critical cell type in the disease. This is underlined by the fact that the best-characterized environmental risk factor for MS is the Epstein-Barr virus (EBV), which can infect and persist in memory B cells throughout life. Several studies have identified changes in anti-EBV immunity in patients with MS. Examples include elevated titers of anti-EBV nuclear antigen 1 (EBNA1) antibodies, interactions of these with the MS-associated HLA-DR15 haplotype, and molecular mimicry with MS autoantigens like myelin basic protein (MBP), anoctamin-2 (ANO2), glial cell adhesion molecule (GlialCAM), and alpha-crystallin B (CRYAB). In this study, we employ a simple in vitro assay to examine the memory B cell antibody repertoire in MS patients and healthy controls. We replicate previous serological data from MS patients demonstrating an increased secretion of anti-EBNA1380-641 IgG in cell culture supernatants, as well as a positive correlation of these levels with autoantibodies against GlialCAM262-416 and ANO21-275. For EBNA1380-641 and ANO21-275, we provide additional evidence suggesting antibody cross-reactivity between the two targets. Further, we show that two efficacious MS treatments - natalizumab (NAT) and autologous hematopoietic stem cell transplantation (aHSCT) - are associated with distinct changes in the EBNA1-directed B cell response and that these alterations can be attributed to the unique mechanisms of action of these therapies. Using an in vitro system, our study confirms MS-associated changes in the anti-EBNA1 memory B cell response, EBNA1380-641 antibody cross-reactivity with ANO21-275, and reveals treatment-associated changes in the immunoglobulin repertoire in MS.

[Ofatumumab in the treatment of multiple sclerosis - A summary of preclinical and clinical data]

BACKGROUND

  B-cell targeted therapies are highly effective in multiple sclerosis (MS). Most of these therapies are administered intravenously at long intervals. Ofatumumab, an anti-CD20 antibody that is administered subcutaneously at low doses on a monthly basis due to its high affinity to the target structure, became available for the treatment of MS in 2021.

METHODS

  An overview of practice-relevant immunological and clinical data on ofatumumab is provided.

RESULTS

  The high affinity of ofatumumab to the target structure allows low dose and low volume administration, with the release and absorption profile after subcutaneous application allowing for high concentrations in the lymph nodes and gradual depletion of B-cells. Rapid onset of action is achieved as well as B-cell repletion within a few months in case of discontinuation of therapy. Long-term data show stable IgG levels over up to four years and high efficacy with respect to relapse rate, progression, and cognition. According to current study data, the effect compared to teriflunomide is greater the earlier therapy is initiated. Ofatumumab has a specific B-cell depletion pattern. CD20 expressing B-cell progenitor cells in the bone marrow are preserved and therefore also the inducibility and differentiation of plasma cells. The formation of a humoral immunological memory is therefore possible. Four-year study data showed no abnormalities in the rate of severe infections or malignancies.

CONCLUSIONS

  Ofatumumab is an innovative B-cell targeted therapy. It is highly effective with a good safety and tolerability profile, well controllable and maintains immunocompetence against pathogens.

Tyrosine kinases: multifaceted receptors at the intersection of several neurodegenerative disease-associated processes

Tyrosine kinases (TKs) are catalytic enzymes activated by auto-phosphorylation that function by phosphorylating tyrosine residues on downstream substrates. Tyrosine kinase inhibitors (TKIs) have been heavily exploited as cancer therapeutics, primarily due to their role in autophagy, blood vessel remodeling and inflammation. This suggests tyrosine kinase inhibition as an appealing therapeutic target for exploiting convergent mechanisms across several neurodegenerative disease (NDD) pathologies. The overlapping mechanisms of action between neurodegeneration and cancer suggest that TKIs may play a pivotal role in attenuating neurodegenerative processes, including degradation of misfolded or toxic proteins, reduction of inflammation and prevention of fibrotic events of blood vessels in the brain. In this review, we will discuss the distinct roles that select TKs have been shown to play in various disease-associated processes, as well as identify TKs that have been explored as targets for therapeutic intervention and associated pharmacological agents being investigated as treatments for NDDs.

De-escalation of Disease-Modifying Therapy for People with Multiple Sclerosis Due to Safety Considerations: Characterizing 1-Year Outcomes in 25 People Who Switched from Ocrelizumab to Diroximel Fumarate

INTRODUCTION

Switching disease-modifying therapy (DMT) may be considered for relapsing-remitting multiple sclerosis (RRMS) if a patient's current therapy is no longer optimal. This was particularly important during the recent COVID-19 pandemic because of considerations around immune deficiency and impaired vaccine response associated with B cell-depleting DMTs. This real-world, single-center study aimed to evaluate change or decline in functional ability and overall disease stability in people with RRMS who were switched from B cell-depleting ocrelizumab (OCRE) to diroximel fumarate (DRF) because of safety concern related to the COVID-19 pandemic.

METHODS

Adults with RRMS were included if they had been clinically stable for ≥ 1 year on OCRE. Data collected at baseline and 1 year post switch included relapse rate, magnetic resonance imaging (MRI), blood work for assessment of peripheral immune parameters, the Cognitive Assessment Battery (CAB), optical coherence tomography (OCT), and patient-reported outcomes (PROs).

RESULTS

Participants (N = 25) had a mean (SD) age of 52 (9) years, and a mean (SD) duration of 26 (8) months' treatment with OCRE before the switch to DRF. Median washout duration since the last OCRE infusion was 7 months (range 4-18 months). No participants relapsed on DRF during follow-up, and all remained persistent on DRF after 1 year. There were no significant changes in peripheral immune parameters, other than an increase in the percentage of CD19+ cells 1 year after switching (p < 0.05). Similarly, there were no significant changes in CAB, OCT, and PROs.

CONCLUSION

These preliminary findings suggest that transition to DRF from OCRE may be an effective treatment option for people with RRMS who are clinically stable but may need to switch for reasons unrelated to effectiveness. Longer follow-up times on larger samples are needed to confirm these observations.