BACKGROUND: Rituximab (RTX) and ocrelizumab (OCR), B cell-depleting therapy targeting CD20 molecules, affect the humoral immune response after vaccination. How these therapies influence T-cell-mediated immune response against SARS-CoV-2 after immunization remains unclear. We aimed to evaluate the humoral and cellular immune response to the COVID-19 vaccine in a cohort of patients with multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), and myasthenia gravis (MG). METHODS: Patients with MS (83), NMOSD (19), or MG (7) undergoing RTX (n=47) or OCR (n=62) treatment were vaccinated twice with the mRNA BNT162b2 vaccine. Antibodies were quantified using the SARS-CoV-2 IgG chemiluminescence immunoassay, targeting the spike protein. SARS-CoV-2-specific T cell responses were quantified by interferon γ release assays (IGRA). The responses were evaluated at two different time points (4-8 weeks and 16-20 weeks following the 2nd dose of the vaccine). Immunocompetent vaccinated individuals (n=41) were included as controls. RESULTS: Almost all immunocompetent controls developed antibodies against the SARS-CoV-2 trimeric spike protein, but only 34.09% of the patients, without a COVID-19 history and undergoing anti-CD20 treatment (via RTX or OCR), seroconverted. This antibody response was higher in patients with intervals of longer than 3 weeks between vaccinations. The duration of therapy was significantly shorter in seroconverted patients (median 24 months), than in the non-seroconverted group. There was no correlation between circulating B cells and the levels of antibodies. Even patients with a low proportion of circulating CD19+ B cells (<1%, 71 patients) had detectable SARS-CoV-2 specific antibody responses. SARS-CoV-2 specific T cell response measured by released interferon γ was detected in 94.39% of the patients, independently of a humoral immune response. CONCLUSION: The majority of MS, MG, and NMOSD patients developed a SARS-CoV-2-specific T cell response. The data suggest that vaccination can induce SARS-CoV-2-specific antibodies in a portion of anti-CD20 treated patients. The seroconversion rate was higher in OCR-treated patients compared to those on RTX. The response represented by levels of antibodies was better in individuals, with intervals of longer than 3 weeks between vaccinations.

• Keywords
• IFN gamma release assay, SARS-CoV-2, SARS-CoV-2 mRNA vaccine, humoral immune response, multiple sclerosis, myasthenia gravis, neuromyelitis optica spectrum disorder,
• MeSH
• Autoimmune Diseases of the Nervous System * MeSH
• COVID-19 * MeSH
• Spike Glycoprotein, Coronavirus MeSH
• Antibodies, Monoclonal, Humanized therapeutic use   MeSH
• Humans MeSH
• Myasthenia Gravis * MeSH
• Antibodies, Viral MeSH
• Rituximab therapeutic use   MeSH
• Multiple Sclerosis * drug therapy   MeSH
• SARS-CoV-2 MeSH
• BNT162 Vaccine MeSH
• Vaccination MeSH
• COVID-19 Vaccines MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Spike Glycoprotein, Coronavirus MeSH
• Antibodies, Monoclonal, Humanized MeSH
• ocrelizumab MeSH Browser
• Antibodies, Viral MeSH
• Rituximab MeSH
• spike protein, SARS-CoV-2 MeSH Browser
• BNT162 Vaccine MeSH
• COVID-19 Vaccines MeSH

Cumulative evidence along several lines indicates that B cells play an important role in the pathological course of multiple sclerosis (MS), neuromyelitisoptica spectrum disorders (NMOSD) and related CNS diseases. This has prompted extensive research in exploring the utility of targeting B cells to contain disease activity in these disorders. In this review, we first recapitulate the development of B cells from their origin in the bone marrow to their migration to the periphery, including the expression of therapy-relevant surface immunoglobulin isotypes. Not only the ability of B cells to produce cytokines and immunoglobulins seems to be essential in driving neuroinflammation, but also their regulatory functions strongly impact pathobiology. We then critically assess studies of B cell depleting therapies, including CD20 and CD19 targeting monoclonal antibodies, as well as the new class of B cell modulating substances, Bruton´s tyrosinekinase (BTK) inhibitors, in MS, NMOSD and MOGAD.

• Keywords
• B cell depletion, autoimmune disease of the central nervous system, multiple sclerosis (MS), myelin oligodendrocyte glycoprotein associated autoimmune disease (MOGAD), neuromyelitisoptica spectrum disorders (NMOSD),
• MeSH
• Autoimmune Diseases * drug therapy   MeSH
• Autoantibodies MeSH
• B-Lymphocytes MeSH
• Central Nervous System MeSH
• Humans MeSH
• Multiple Sclerosis * drug therapy   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Autoantibodies MeSH

BACKGROUND: Inebilizumab is an anti-CD19 antibody approved for the treatment of neuromyelitis optica spectrum disorder (NMOSD) in adults with aquaporin-4 autoantibodies. The relationship between B-cell, plasma-cell (PC), and immunoglobulin depletion with longitudinal reductions in NMOSD activity after inebilizumab treatment was characterised post hoc in an exploratory analysis from the N-MOmentum study (NCT02200770). METHODS: Peripheral blood CD20+ B cells, PC gene signature, and immunoglobulin levels were assessed throughout N-MOmentum (follow-up ≥2.5 years); correlations with clinical metrics and magnetic resonance imaging (MRI) lesion activity were assessed. FINDINGS: Inebilizumab induced durable B-cell and PC depletion within 1 week versus placebo. Although no association was observed between B-cell counts at time of attack and NMOSD activity, depth of B-cell depletion after the first dosing period correlated with clinical outcomes. All participants receiving inebilizumab demonstrated a robust long-term therapeutic response, and participants with ≤4 cells/μL after the first 6-month dosing interval had persistently deeper B-cell depletion, lower annualised attack rates (estimated rate [95% CI]: 0.034 [0.024-0.04] vs 0.086 [0.056-0.12]; p = 0.045), fewer new/enlarging T2 MRI lesions (0.49 [0.43-0.56] vs 1.36 [1.12-1.61]; p < 0.0001), and a trend towards decreased Expanded Disability Status Scale worsening (0.076 [0.06-0.10] vs 0.14 [0.10-0.18]; p = 0.093). Antibodies to inebilizumab, although present in a proportion of treated participants, did not alter outcomes. INTERPRETATION: This analysis suggests that compared with placebo, inebilizumab can provide specific, rapid, and durable depletion of B cells in participants with NMOSD. Although deep and persistent CD20+ B-cell depletion correlates with long-term clinical stability, early, deep B-cell depletion correlates with improved disease activity metrics in the first 2 years. FUNDING: Horizon Therapeutics (formerly from Viela Bio/MedImmune).

• Keywords
• Anti-CD19 monoclonal antibody, Aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder, B-cell suppression, Devic disease,
• MeSH
• Antigens, CD19 MeSH
• Autoantibodies MeSH
• B-Lymphocytes MeSH
• Adult MeSH
• Double-Blind Method MeSH
• Humans MeSH
• Magnetic Resonance Imaging MeSH
• Neuromyelitis Optica * drug therapy   pathology   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Publication type
• Journal Article MeSH
• Clinical Trial, Phase II MeSH
• Clinical Trial, Phase III MeSH
• Multicenter Study MeSH
• Randomized Controlled Trial MeSH
• Names of Substances
• Antigens, CD19 MeSH
• Autoantibodies MeSH