B cell-directed therapies in multiple sclerosis

Therapeutic effect of ofatumumab in patients with myasthenia gravis: immunoregulation of follicular T helper cells and T helper type 17 cells

Introduction

This study aimed to study the therapeutic effects of ofatumumab in patients with myasthenia gravis (MG) in addition to the immunomodulatory effects on peripheral follicular T helper (Tfh) cells and T helper type 17 (Th17) cells.

Methods

Thirty-one patients with anti-acetylcholine receptor (AChR) antibody-positive MG were included in this study. At weeks 0, 1, 2, and 4, an initial dose of 20 mg of ofatumumab was injected subcutaneously, with a 2-month follow-up after completing this first cycle. At baseline, 1 month, and 3 months, we assessed the Quantitative MG (QMG), 15-item MG-Quality of Life (MG-QOL15), and MG-Activities of Daily Living (MG-ADL) scales and measured the frequencies of Tfh, Th17, and B cells and the levels of anti-AChR antibody, IL-6, IL-21, and IL-17 in the peripheral blood.

Results

At 1 month and 3 months, the QMG, MG-QOL15, and MG-ADL scores were all significantly reduced. At 3 months, doses of prednisone were reduced by an average of 37%. Decreased frequencies of Tfh and Th17 cells, depletion of B cells, and reduced levels of IL-6, IL-21, and IL-17 were all observed at 1 month or 3 months.

Discussion

Therefore, the therapeutic effect of ofatumumab could be detected after one cycle of treatment, which was maintained for 2 months. The immunomodulatory effect of ofatumumab during the observation period may involve depletion of B cells, reduction of Tfh and Th17 cells frequencies, and reduced levels of IL-6, IL-21, and IL-17. The findings provide novel data for the potential application of ofatumumab in MG.

Evaluation of BAFF, APRIL and CD40L in Ocrelizumab-Treated pwMS and Infectious Risk

BACKGROUND

The anti-CD20 monoclonal antibody ocrelizumab has been widely employed in the treatment of people with multiple sclerosis (pwMS). However, its B-cell-depleting effect may induce a higher risk of infectious events and alterations in the secretion of B-cell-activating factors, such as BAFF, APRIL and CD40L.

METHODS

The aim of this study was to investigate plasma BAFF, APRIL and CD40L levels and their relationship with infectious risk in ocrelizumab-treated pwMS at baseline (T0), at 6 months (T6) and at 12 months (T12) after starting the treatment. As a control group, healthy donors (HD) were enrolled too.

RESULTS

A total of 38 pwMS and 26 HD were enrolled. At baseline, pwMS showed higher plasma BAFF (p < 0.0001), APRIL (p = 0.0223) and CD40L (p < 0.0001) levels compared to HD. Compared to T0, plasma BAFF levels were significantly increased at both T6 and T12 (p < 0.0001 and p < 0.0001, respectively). Whereas plasma APRIL and CD40L levels were decreased at T12 (p = 0.0003 and p < 0.0001, respectively). When stratifying pwMS according to the development of an infectious event during the 12-month follow-up period in two groups-with (14) and without an infectious event (24)-higher plasma BAFF levels were observed at all time-points; significantly, in the group with an infectious event compared to the group without an infectious event (T0: p < 0.0001, T6: p = 0.0056 and T12: p = 0.0400). Conclusions: BAFF may have a role as a marker of immune dysfunction and of infectious risk.

Assessment of the treating physicians' first-hand experience with handling and satisfaction of ofatumumab therapy: findings from the PERITIA survey conducted in Europe

BACKGROUND

Real-world evidence on experience and satisfaction of ofatumumab as a treatment option for relapsing multiple sclerosis (RMS) is limited.

OBJECTIVE

To present cumulative responses from a questionnaire related to first-hand experience of treating physicians on handling and convenience of ofatumumab therapy along with concerns related to COVID-19.

METHODS

PERITIA was a multicentre survey conducted to collect responses from the ASCLEPIOS I/II trial investigators from Europe via an online questionnaire.

RESULTS

Forty-six physicians (Germany, n = 14; Spain, n = 12; Portugal, n = 10; Italy, n = 10) completed the survey. Overall, 43% of the physicians considered the benefit-risk ratio of ofatumumab as very good. Over 93% were in favour of ofatumumab self-administration at home and the majority (83%) believed it to be completely true that self-administration of ofatumumab eases the burden for patients in terms of time. All investigators would like to potentially use anti-CD20 therapy as a long-term strategy. Even during the COVID-19 pandemic, physicians were in favour of a self-administration of MS therapy at home over other anti-CD20 therapy infusions.

CONCLUSION

European neurologists who were part of this survey considered the benefit-risk-ratio of ofatumumab as favourable and the monthly self-administered subcutaneous injections offering convenience for patients in the clinical practice.

B cell-directed therapies: a new era in Multiple Sclerosis treatment

Multiple sclerosis (MS) is a chronic autoimmune demyelinating disease of the central nervous system (CNS) that often progresses to severe disability. Previous studies have highlighted the role of T cells in disease pathophysiology; however, the success of B-cell-targeted therapies has led to an increased interest in how B cells contribute to disease immunopathology. In this review, we summarize evidence of B-cell involvement in MS disease mechanisms, starting with pathology and moving on to review aspects of B cell immunobiology potentially relevant to MS. We describe current theories of critical B cell contributions to the inflammatory CNS milieu in MS, namely (i) production of autoantibodies, (ii) antigen presentation, (iii) production of proinflammatory cytokines (bystander activation), and (iv) EBV involvement. In the second part of the review, we summarize medications that have targeted B cells in patients with MS and their current position in the therapeutic armamentarium based on clinical trials and real-world data. Covered therapeutic strategies include the targeting of surface molecules such as CD20 (rituximab, ocrelizumab, ofatumumab, ublituximab) and CD19 (inebilizumab), and molecules necessary for B-cell activation such as B cell activating factor (BAFF) (belimumab) and Bruton's Tyrosine Kinase (BTK) (evobrutinib). We finally discuss the use of B-cell-targeted therapeutics in pregnancy.

CSF Kappa Free Light Chains: Cutoff Validation for Diagnosing Multiple Sclerosis

OBJECTIVE

To determine and validate a cerebrospinal fluid (CSF) κ (KCSF) value statistically comparable to detection of CSF-specific oligoclonal bands (OCB) to support the diagnosis of multiple sclerosis (MS).

PATIENTS AND METHODS

A total of 702 retrospective and 657 prospective paired CSF/serum samples from residual waste samples of physician-ordered OCB tests were obtained and tested for KCSF at Mayo Clinic. Charts were reviewed by a neurologist blinded to KCSF results. Specificity and sensitivity for MS diagnosis were evaluated to establish a diagnostic cutoff value for KCSF in the retrospective cohort and then validated in the prospective cohort.

RESULTS

Retrospective and prospective subgroups, respectively, included MS (n=85, 70), non-MS (n=615, 585), and undetermined diagnosis (excluded, n=2, 2). The retrospective data established a KCSF cutoff value of 0.1 mg/dL to be comparable to OCB testing. In the retrospective subgroup, KCSF vs OCB sensitivities for diagnosis of MS were 68.2% vs 75.0% (P=.08) and specificities were 86.1% vs 87.6% (P=.27). The KCSF area under the receiver operating characteristic curve was 0.772 (95% CI, 0.720 to 0.824), and for OCB was 0.813 (95% CI, 0.764 to 0.861). The prospective cohort was then used to validate the diagnostic KCSF value of 0.1 mg/dL; KCSF vs OCB sensitivities were 78.6% for both (P>.99) and specificities were 87.1% vs 89.4% (P=.09).

CONCLUSION

The KCSF value of 0.1 mg/dL is a valid alternative to OCB testing, offering a standardized quantitative measure, eliminating human error, reducing cost and turnaround time, with no significant difference in sensitivity and specificity. This study provides class I evidence that a KCSF value of 0.1 mg/dL can be used in place of OCB testing to support the diagnosis of MS.

Ocrelizumab in relapsing and primary progressive multiple sclerosis: Pharmacokinetic and pharmacodynamic analyses of OPERA I, OPERA II and ORATORIO

Aims

Ocrelizumab is a humanized monoclonal antibody that selectively targets CD20‐positive B cells and is indicated for treatment of patients with relapsing forms of multiple sclerosis (RMS) or primary progressive multiple sclerosis (PPMS). The pharmacokinetics and pharmacodynamics of ocrelizumab in patients with RMS or PPMS were assessed.

Methods

A population pharmacokinetic model was developed based on data from the Phase II study and the Phase III studies OPERA I and OPERA II in patients with RMS. Data from the ORATORIO Phase III study in patients with PPMS became available after model finalization and was used for external model evaluation.

Results

The ocrelizumab serum concentration vs time course was accurately described by a 2‐compartment model with time‐dependent clearance. Body weight was found to be the main covariate. The area under the concentration–time curve over the dosing interval was estimated to be 26% higher for patients with RMS weighing <60 kg and 21% lower for patients weighing >90 kg when compared with the 60–90 kg group. The terminal half‐life of ocrelizumab was estimated as 26 days. The extent of B‐cell depletion in blood, as the pharmacodynamic marker, was greater with increasing ocrelizumab exposure.

Conclusion

The pharmacokinetics of ocrelizumab was described with pharmacokinetic parameters typical for an immunoglobulin G1 monoclonal antibody, with body weight as the main covariate. The pharmacokinetics and B‐cell depletion in blood were comparable across the RMS and PPMS trials, and the extent of blood B‐cell depletion was greater with higher exposure.

Ofatumumab – A Potential Subcutaneous B-cell Therapy for Relapsing Multiple Sclerosis

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Anti-drug Antibodies Against a Novel Humanized Anti-CD20 Antibody Impair Its Therapeutic Effect on Primary Biliary Cholangitis in Human CD20- and FcγR-Expressing Mice

There is considerable interest in expanding B cell-targeted therapies in human autoimmune diseases. However, clinical trials in human primary biliary cholangitis (PBC) using a chimeric antibody against human CD20 (hCD20) have showed limited efficacy. Two potential explanations for these disappointing results are the appearance of anti-drug antibodies (ADAs) and the high frequency of patients with moderate PBC or patients who had failed ursodeoxycholic acid treatment. Here, we studied a novel humanized IgG1 antibody against hCD20 and explored its efficacy in early stage PBC using a well-defined murine model. We developed a unique murine model consisting of dnTGF-βRII mice expressing hCD20 and human Fcγ receptors (hFcγRs). Beginning at 4–6 weeks of age, equivalent to stage I/II human PBC, female mice were given weekly injections of an anti-hCD20 antibody (TKM-011) or vehicle control, and monitored for liver histology as well as a broad panel of immunological readouts. After 16 weeks' treatment, we observed a significant reduction in portal inflammation, a decrease in liver-infiltrating mononuclear cells as well as a reduction in liver CD8⁺ T cells. Importantly, direct correlations between numbers of liver non-B cells and B cells (r = 0.7426, p = 0.0006) and between numbers of liver memory CD8⁺ T cells and B cells (r = 0.6423, p = 0.0054) were apparent. Accompanying these changes was a dramatic reduction in anti-mitochondrial antibodies (AMAs), interleukin (IL)-12p40 and IL-5, and elevated levels of the anti-inflammatory chemokine CXCL1/KC. In mice that developed ADAs, clinical improvements were less pronounced. Sustained treatment with B cell-targeted therapies may broadly inhibit effector pathways in PBC, but may need to be administered early in the natural history of PBC.

The role of B cells in multiple sclerosis: Current and future therapies

While it was long held that T cells were the primary mediators of multiple sclerosis (MS) pathogenesis, the beneficial effects observed in response to treatment with Rituximab (RTX), a monoclonal antibody (mAb) targeting CD20, shed light on a key contributor to MS that had been previously underappreciated: B cells. This has been reaffirmed by results from clinical trials testing the efficacy of subsequently developed B cell-depleting mAbs targeting CD20 as well as studies revisiting the effects of previous disease-modifying therapies (DMTs) on B cell subsets thought to modulate disease severity. In this review, we summarize current knowledge regarding the complex roles of B cells in MS pathogenesis and current and potential future B cell-directed therapies.

Ocrelizumab: a new milestone in multiple sclerosis therapy

B cells play a central role in the pathogenesis of multiple sclerosis (MS): they are involved in the activation of pro-inflammatory T cells, secretion of pro-inflammatory cytokines and production of autoantibodies directed against myelin. Hence, the use of B cell-depleting monoclonal antibodies as therapy for autoimmune diseases, including MS, has increased in recent years. Previous results with rituximab, the first therapeutic B cell-depleting chimeric monoclonal antibody that showed efficacy in MS clinical trials, encouraged researchers to evaluate the efficacy of a humanized anti-CD20 antibody, ocrelizumab, in MS. A large phase II clinical trial in patients with relapsing-remitting MS (RRMS) designed to explore the effects of two doses of ocrelizumab (600 mg and 2000 mg) compared with placebo showed a pronounced effect on radiological and relapse-related outcomes. These results were confirmed in two phase III trials (OPERA I and II) that compared the efficacies of ocrelizumab with interferon beta-1a in patients with relapsing MS, and showed decreased annualized relapse rates (46% in OPERA I and 47% in OPERA II), as well as fewer numbers of gadolinium-enhanced lesions on magnetic resonance imaging (MRI) scans (94% in OPERA I and 95% in OPERA II). Notably, ocrelizumab is the first drug to lower rates of clinical and MRI-evidenced progression in patients with primary progressive MS (PPMS). The phase III trial (ORATORIO) in patients with PPMS met its primary efficacy endpoint: the percentage of patients with 12-week confirmed disability progression was significantly lower in the active treatment group (32.9%) than in patients receiving placebo (39.3%). In March 2017, this evidence led the US Food and Drug Administration to approve the licence for ocrelizumab (Ocrevus®) as a treatment for MS, as the first treatment approved for PPMS and as the first monoclonal antibody for secondary progressive MS.

Serum heat shock protein 70 levels as a biomarker for inflammatory processes in multiple sclerosis

Background

Inflammatory and neurodegenerative processes are hallmarks of multiple sclerosis (MS). The synthesis of the major stress-inducible heat shock protein 70 (Hsp70) is induced by inflammation.

Objective

The purpose of this study is to determine whether Hsp70 in serum can serve as a potential biomarker to distinguish inflammatory and neurodegenerative processes in MS.

Methods

Serum was obtained from 94 patients: 26 clinically isolated syndrome (CIS), 40 relapsing–remitting MS (RRMS), 19 secondary progressive MS (SPMS), and nine primary progressive MS (PPMS). As controls, serum samples were collected from patients with non-inflammatory neurological diseases (NINDs, n = 41), other inflammatory neurological diseases (OINDs, n = 28) and healthy donors (HDs, n = 114). Serum levels of Hsp70 were quantified using the enzyme-linked immunosorbent assay detecting free and liposomal Hsp70 (lipHsp70 ELISA).

Results

Patients with MS displayed significantly higher Hsp70 serum levels than HDs (p < 0.001) and significantly lower levels than OINDs (p = 0.001). A subgroup analysis revealed that Hsp70 serum levels of CIS/RRMS patients are significantly higher than those of patients with progressive MS (SPMS/PPMS) (p < 0.05).

Conclusion

Inflammation causes the release of Hsp70 into the blood. As CIS/RRMS are associated with higher Hsp70 serum levels than progressive MS, serum Hsp70 levels might provide a marker for inflammatory processes.

Managing Epstein-Barr virus and other risk factors in MS-Future perspectives

Here, we discuss the rationale and feasibility of treatment directed against the modifiable risk factors in multiple sclerosis. The established environmental risk factors vitamin D insufficiency, cigarette smoke exposure, adolescence overweight, and Epstein-Barr virus infection are reviewed. Already available measures to target these risk factors are discussed.

B-cell-targeted therapies in relapsing forms of MS

In recent years, there has been a significant increase in the therapeutic options available for the management of relapsing forms of MS. Therapies primarily targeting B cells, including therapeutic anti-CD20 monoclonal antibodies, have been evaluated in phase I, phase II, and phase III clinical trials. Results of these trials have shown their efficacy and relatively tolerable adverse effect profiles, suggesting a favorable benefit-to-risk ratio. In this review, we discuss the pathogenic role of B cells in MS and the rationale behind the utilization of B-cell depletion as a therapeutic cellular option. We also discuss the data of clinical trials for anti-CD20 antibodies in relapsing forms of MS and existing evidence for other B-cell–directed therapeutic strategies.

Imaging B Cells in a Mouse Model of Multiple Sclerosis Using 64Cu-Rituximab PET

B lymphocytes are a key pathologic feature of multiple sclerosis (MS) and are becoming an important therapeutic target for this condition. Currently, there is no approved technique to noninvasively visualize B cells in the central nervous system (CNS) to monitor MS disease progression and response to therapies. Here, we evaluated ⁶⁴Cu-rituximab, a radiolabeled antibody specifically targeting the human B cell marker CD20, for its ability to image B cells in a mouse model of MS using PET. Methods: To model CNS infiltration by B cells, experimental autoimmune encephalomyelitis (EAE) was induced in transgenic mice that express human CD20 on B cells. EAE mice were given subcutaneous injections of myelin oligodendrocyte glycoprotein fragment_1-125 emulsified in complete Freund adjuvant. Control mice received complete Freund adjuvant alone. PET imaging of EAE and control mice was performed 1, 4, and 19 h after ⁶⁴Cu-rituximab administration. Mice were perfused and sacrificed after the final PET scan, and radioactivity in dissected tissues was measured with a γ-counter. CNS tissues from these mice were immunostained to quantify B cells or were further analyzed via digital autoradiography. Results: Lumbar spinal cord PET signal was significantly higher in EAE mice than in controls at all evaluated time points (e.g., 1 h after injection: 5.44 ± 0.37 vs. 3.33 ± 0.20 percentage injected dose [%ID]/g, P < 0.05). ⁶⁴Cu-rituximab PET signal in brain regions ranged between 1.74 ± 0.11 and 2.93 ± 0.15 %ID/g for EAE mice, compared with 1.25 ± 0.08 and 2.24 ± 0.11 %ID/g for controls (P < 0.05 for all regions except striatum and thalamus at 1 h after injection). Similarly, ex vivo biodistribution results revealed notably higher ⁶⁴Cu-rituximab uptake in the brain and spinal cord of huCD20tg EAE, and B220 immunostaining verified that increased ⁶⁴Cu-rituximab uptake in CNS tissues corresponded with elevated B cells. Conclusion: B cells can be detected in the CNS of EAE mice using ⁶⁴Cu-rituximab PET. Results from these studies warrant further investigation of ⁶⁴Cu-rituximab in EAE models and consideration of use in MS patients to evaluate its potential for detecting and monitoring B cells in the progression and treatment of this disease. These results represent an initial step toward generating a platform to evaluate B cell-targeted therapeutics en route to the clinic.

Monoclonal antibodies in the treatment of multiple sclerosis: emergence of B-cell-targeted therapies

Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS, and one of the most common causes of disability in young adults. Over the last decade, new disease-modifying therapies have emerged, including monoclonal antibodies (mAbs) that provide highly targeted therapies with greater efficacy than platform therapies. In particular, monoclonal antibodies directed against CD20-positive B cells have shown remarkable results in recent clinical trials and renewed interest in the mechanism of B cell-depleting therapies to ameliorate relapse activity and progression in MS. Here, we review the mechanisms of action and clinical evidence of approved and emerging mAbs, with a focus on B cell-targeted therapies.

Safety, pharmacokinetics, and pharmacodynamics of BMS-986142, a novel reversible BTK inhibitor, in healthy participants

PURPOSE

BMS-986142 is an oral, small-molecule reversible inhibitor of Bruton's tyrosine kinase. The main objectives of our phase I studies were to characterize the safety and tolerability, pharmacokinetics, and pharmacodynamics of BMS-986142 in healthy participants, and to investigate the potential for the effect of BMS-986142 on the PK of methotrexate (MTX) in combination.

METHODS

In a combined single ascending dose and multiple ascending dose study, the safety, pharmacokinetics, and pharmacodynamics of BMS-986142 were assessed in healthy non-Japanese participants following administration of a single dose (5-900 mg) or multiple doses (25-350 mg, once daily for 14 days). In a drug-drug interaction study, the effect of BMS-986142 (350 mg, once daily for 5 days) on the single-dose pharmacokinetics of MTX (7.5 mg) was assessed in healthy participants.

RESULTS

BMS-986142 was generally well tolerated, alone and in combination with MTX. BMS-986142 was rapidly absorbed with peak concentrations occurring within 2 h, and was eliminated with a mean half-life ranging from 7 to 11 h. Exposure of BMS-986142 appeared dose proportional within the dose ranges tested. A dose- and concentration-dependent inhibition of CD69 expression was observed following administration of BMS-986142. BMS-986142 did not affect the pharmacokinetics of MTX.

CONCLUSIONS

BMS-986142 was well tolerated at the doses tested, had pharmacokinetic and pharmacodynamic profiles which support once-daily dosing, and can be coadministered with MTX without the pharmacokinetic interaction of BMS-986142 on MTX.

Effects of in vivo and in vitro administration of neuro-Behcet's disease IgG

Antibodies directed against membrane antigens of neuronal axonal processes (neuropil) have been recently identified in neuro-Behcet's disease (NBD) patients. To delineate the potential pathogenic action of these antibodies, pooled sera from seven NBD patients with neuropil antibodies and seven healthy controls were divided into purified IgG and IgG-depleted serum (IgG-DS) fractions and each fraction was administered into lateral ventricles of rats. NBD IgG-injected rats showed reduced locomotor activity in the open field test as compared to NBD IgG-DS, healthy control IgG, healthy control IgG-DS and PBS injected rats (n = 10 for each group). There were no significant differences among treatment groups by means of anxiety-like behaviors (assessed by elevated plus maze test) and learning/memory functions (assessed by passive avoidance test). Administration of NBD IgG on cultured SH-SY5Y neuroblastoma cells induced significantly increased cell death and apoptosis (as measured by nucleosome levels in the supernatants) as compared to other treatment groups. Our results suggest that IgGs isolated from sera of neuropil antibody-positive NBD patients have a neurotoxic action, which is presumably mediated by apoptotic mechanisms. Motor deficits frequently observed in NBD patients might at least partially be caused by the pathogenic action of anti-neuronal IgG.

Diversity of immune cell types in multiple sclerosis and its animal model: Pathological and therapeutic implications

Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system with an autoimmune attack on the components of the myelin sheath and axons. The etiology of the disease remains largely unknown, but it is commonly acknowledged that the development of MS probably results from the interaction of environmental factors in conjunction with a genetic predisposition. Current therapeutic approaches can only ameliorate the clinical symptoms or reduce the frequency of relapse in MS. Most drugs used in this disease broadly suppress the functions of immune effector cells, which can result in serious side effects. Thus, new therapeutic methods resulting in greater efficacy and lower toxicity are needed. Toward this end, cell-based therapies are of increasing interest in the treatment of MS. Several immunoregulatory cell types, including regulatory T cells, regulatory B cells, M2 macrophages, tolerogenic dendritic cells, and stem cells, have been developed as novel therapeutic tools for the treatment of MS. In this Review, we summarize studies on the application of these cell populations for the treatment of MS and its animal model, experimental autoimmune encephalomyelitis, and call for further research on applications and mechanisms by which these cells act in the treatment of MS. © 2017 The Authors Journal of Neuroscience Research Published by Wiley Periodicals, Inc.

Environmental modifiable risk factors for multiple sclerosis: Report from the 2016 ECTRIMS focused workshop

Multiple sclerosis (MS) is an inflammatory and neurodegenerative demyelinating disease of the central nervous system (CNS), most likely autoimmune in origin, usually beginning in early adulthood. The aetiology of the disease is not well understood; it is viewed currently as a multifactorial disease which results from complex interactions between genetic predisposition and environmental factors, of which a few are potentially modifiable. Improving our understanding of these factors can lead to new and more effective approaches to patient counselling and, possibly, prevention and management of the disease. The 2016 focused workshop of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) addressed the topic of environmental, modifiable risk factors for MS, gathering experts from around the world, to collate experimental and clinical research into environmental factors that have been associated with the disease onset and, in a few cases, disease activity and progression. A number of factors, including infections, vitamin D deficiency, diet and lifestyle factors, stress and comorbidities, were discussed. The meeting provided a forum to analyse available evidence, to identify inconsistencies and gaps in current knowledge and to suggest avenues for future research.

Targeting B cells in relapsing-remitting multiple sclerosis: from pathophysiology to optimal clinical management

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease that is caused by an autoimmune response against central nervous system (CNS) structures. Traditionally considered a T-cell-mediated disorder, the contribution of B cells to the pathogenesis of MS has long been debated. Based on recent promising clinical results from CD20-depleting strategies by three therapeutic monoclonal antibodies in clinical phase II and III trials (rituximab, ocrelizumab and ofatumumab), targeting B cells in MS is currently attracting growing interest among basic researchers and clinicians. Many questions about the role of B and plasma cells in MS remain still unanswered, ranging from the role of specific B-cell subsets and functions to the optimal treatment regimen of B-cell depletion and monitoring thereafter. Here, we will assess our current knowledge of the mechanisms implicating B cells in multiple steps of disease pathology and examine current and future therapeutic approaches for the treatment of MS.

Serum BAFF levels, Methypredsinolone therapy, Epstein-Barr Virus and Mycobacterium avium subsp. paratuberculosis infection in Multiple Sclerosis patients

Elevated B lymphocyte activating factor BAFF levels have been reported in multiple sclerosis (MS) patients; moreover, disease-modifying treatments (DMT) have shown to influence blood BAFF levels in MS patients, although the significance of these changes is still controversial. In addition, BAFF levels were reported increased during infectious diseases. In our study, we wanted to investigate on the serum BAFF concentrations correlated to the antibody response against Mycobacterium avium subspecies paratuberculosis (MAP), Epstein-Barr virus (EBV) and their human homologous epitopes in MS and in patients affected with other neurological diseases (OND), divided in Inflammatory Neurological Diseases (IND), Non Inflammatory Neurological Diseases (NIND) and Undetermined Neurological Diseases (UND), in comparison to healthy controls (HCs). Our results confirmed a statistically significant high BAFF levels in MS and IND patients in comparison to HCs but not NIND and UND patients. Interestingly, BAFF levels were inversely proportional to antibodies level against EBV and MAP peptides and the BAFF levels significantly decreased in MS patients after methylprednisolone therapy. These results implicate that lower circulating BAFF concentrations were present in MS patients with humoral response against MAP and EBV. In conclusion MS patients with no IgGs against EBV and MAP may support the hypothesis that elevated blood BAFF levels could be associated with a more stable disease.