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Background: Ocrelizumab and rituximab are frequently used treatments for multiple sclerosis (MS). Data on switching from rituximab to ocrelizumab is limited. Objectives: To assess the frequency, severity, and factors of infusion related reactions (IRRs) in patients with MS who switch from rituximab to ocrelizumab, compared to those who stay on rituximab. Methods: Prospective study on MS patients aged 18–65, on rituximab for at least 2 cycles, who either switched to ocrelizumab (switch group) or stayed on rituximab (comparator group) (n = 100 each). Participants were followed for IRRs, safety, and tolerability over 12 months. Results: The proportion of IRRs in patients who continue on rituximab (14%) were similar to those who switched to ocrelizumab on Day 1 (14%; p = 1.000) and Week 24 (12%; p = 0.647) but higher than at Day 15 (4%; 0.005). The risk of IRRs for the switch group was associated with the presence of B cells (CD19 and/or CD20 counts ≥1%) increasing by 5.01 (1.49, 16.82) times on Day 1 (p = 0.007). Antidrug antibodies to ocrelizumab were not associated with IRRs. No other safety concerns were identified in switching to ocrelizumab. Conclusion: IRRs are similar between both groups, which suggests that it is safe to switch from rituximab to ocrelizumab. [ABSTRACT FROM AUTHOR]

CXCL13, a B-cell chemokine, has been proposed as a biomarker in a variety of conditions, some of which can mimic multiple sclerosis and can have very high levels. In this case-control study, cerebrospinal fluid (CSF) CXCL13 was elevated in multiple sclerosis, neuromyelitis optica and other inflammatory neurological controls compared with noninflammatory controls. Levels did not differentiate disease groups. For all subjects taken together, CSF CXCL13 correlated with CSF WBC, oligoclonal band numbers, CSF protein, EDSS, and neurofilament levels. In subgroup analyses, CSF CXCL13 correlated with CSF WBC in neuromyelitis optica and IgG index in multiple sclerosis. Additionally, serum CXCL13 was elevated in neuromyelitis optica. [ABSTRACT FROM PUBLISHER]

Emerging evidence is encouraging and suggests that a substantial proportion of patients without antibody responses (due to anti-CD20 therapy or other etiologies) to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccines develop T cell responses. However, antigen-specific T cellular responses are notoriously difficult to assess clinically, given the lack of such assays under satisfactory CAP/CLIA regulation, and the laborious nature of the flow cytometric assessment. To evaluate the ability to apply a clinically feasible assay to measure T cellular responses to SARS-CoV-2 mRNA vaccination, we compared flow cytometric and enzyme-linked immunosorbent assay (ELISA) based assays in 24 participants treated with anti-CD20 therapy. T cellular activation (CD69 + CD137+ surface expression, i.e., activation induced markers [AIM]) and intracellular interferon gamma (INFγ) production via flow cytometry was compared to plasma Interferon Gamma Release Assay (IGRA) via ELISA. Plasma INFγ production measured by IGRA correlated with the percent of INFγ-producing AIM positive T cells, supporting the use of IGRA assay as a robust assessment of T cellular response to the SARS-CoV-2 vaccine for B-cell depleted patients that is clinically feasible, time efficient, and cost effective. [Display omitted] [ABSTRACT FROM AUTHOR]

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system, thought to be mediated by myelin-specific CD4+ T cells. However, B cell depletion has proven to be an effective therapy for MS, but the mechanism is not well understood. This study was designed to determine how B cell depletion changes lymphocyte profiles. During a phase IIa clinical trial with ublituximab, a novel CD20 antibody, blood was collected from 48 MS patients at 11 time points over 24 weeks and the lymphocyte profiles were analyzed by flow cytometry. The percentage of naïve CD4+ and CD8+ T cells increased, while the percentage of both effector and central memory T cells declined. CD4+ Th1 effector cells decreased, while there was a significant increase in CD4+ regulatory T cells. The depletion of B cells had a favorable shift in the lymphocyte landscape, reducing the number of naïve T cells becoming activated and transitioning to memory T cells. The ratio of Th1 cells to CD4+ regulatory T cells declined, suggesting that immune regulation was being restored. These data suggest that loss of B cells as antigen presenting cells is a major mechanism of action for the beneficial effects of CD20 antibody therapy in MS. Unlabelled Image • B cell depletion in MS patients reduces memory T cells and increases naïve T cells, suggesting that T cell activation is reduced when B cells are low. • Be cell depletion in MS patients reduces CD4+ Th1 cells and increases the percentage of CD4+ regulatory T cells. • NK cell subsets change following anti-CD20 therapy, suggesting that NK cell-mediated killing of B cells has long-term consequences. [ABSTRACT FROM AUTHOR]

CD40 interacts with CD40L and plays an essential role in immune regulation and homeostasis. Recent research findings, however, support a pathogenic role of CD40 in a number of autoimmune diseases. We previously showed that memory B cells from relapsingremitting multiple sclerosis (RRMS) patients exhibited enhanced proliferation with CD40 stimulation compared with healthy donors. In this study, we used a multiparameter phosflow approach to analyze the phosphorylation status of NF-κB and three major MAPKs (P38, ERK, and JNK), the essential components of signaling pathways downstream of CD40 engagement in B cells from MS patients. We found that memory and naive B cells from RRMS and secondary progressive MS patients exhibited a significantly elevated level of phosphorylated NF-κB (p-P65) following CD40 stimulation compared with healthy donor controls. Combination therapy with IFN-β-1a (Avonex) and mycophenolate mofetil (Cellcept) modulated the hyperphosphorylation of P65 in B cells of RRMS patients at levels similar to healthy donor controls. Lower disease activity after the combination therapy correlated with the reduced phosphorylation of P65 following CD40 stimulation in treated patients. Additionally, glatiramer acetate treatment also significantly reduced CD40-mediated P65 phosphorylation in RRMS patients, suggesting that reducing CD40-mediated p-P65 induction may be a general mechanism by which some current therapies modulate MS disease. [ABSTRACT FROM AUTHOR]

B cell depletion therapy has been shown to be beneficial in multiple sclerosis (MS). However, the mechanism by which B cell depletion mediates its beneficial effects in MS is still unclear. To better understand how B cell depletion may benefit patients with a disease previously thought to be primarily mediated by CD4 T cells, immune profiles were monitored in 48 patients in a phase II trial of ublituximab, a glycoengineered CD20 monoclonal antibody, at 18 time points over a year. As we previously described there was a significant shift in the percentages of T cells, NK cells, and myeloid cells following the initial dose of ublituximab, but this shift normalized within a week and these populations remained stable for the duration of the study. However, T cell subsets changed with an increase in the percentage of naïve CD4 and CD8 T cells and a decline in memory T cells. Importantly, the percentage of Th1 and CD4+GM-CSF+ T cells decreased, while the percentage of Tregs continued to increase over the year. Ublituximab not only depleted CD20+ B cells, but also CD20+ T cells. The favorable changes in the T cell subsets may contribute to the beneficial effects of B cell depletion therapy. [Display omitted] • B cell depletion causes an increase in naïve T cells, and a reciprocal reduction in memory T cells. • Th1 cells and GMCSF+CD4+ T cells, which are potentially pathogenic in MS, decline following B cell depletion therapy. • Tregs, which have the potential to suppress pathogenic T cells in MS, increase in patients on B cell depletion therapy. • Ublituximab efficiently depletes CD20+ T cells. [ABSTRACT FROM AUTHOR]