Cellular and Humoral Immunity to SARS-CoV-2 Infection in Multiple Sclerosis Patients on Ocrelizumab and Other Disease-Modifying Therapies: A Multi-Ethnic Observational Study.

OBJECTIVE: The objective of this study was to determine the impact of multiple sclerosis (MS) disease-modifying therapies (DMTs) on the development of cellular and humoral immunity to severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection. METHODS: Patients with MS aged 18 to 60 years were evaluated for anti-nucleocapsid and anti-Spike receptor-binding domain (RBD) antibody with electro-chemiluminescence immunoassay; antibody responses to Spike protein, RBD, N-terminal domain with multiepitope bead-based immunoassays (MBI); live virus immunofluorescence-based microneutralization assay; T-cell responses to SARS-CoV-2 Spike using TruCulture enzyme-linked immunosorbent assay (ELISA); and IL-2 and IFNγ ELISpot assays. Assay results were compared by DMT class. Spearman correlation and multivariate analyses were performed to examine associations between immunologic responses and infection severity. RESULTS: Between January 6, 2021, and July 21, 2021, 389 patients with MS were recruited (mean age 40.3 years; 74% women; 62% non-White). Most common DMTs were ocrelizumab (OCR)-40%; natalizumab -17%, Sphingosine 1-phosphate receptor (S1P) modulators -12%; and 15% untreated. One hundred seventy-seven patients (46%) had laboratory evidence of SARS-CoV-2 infection; 130 had symptomatic infection, and 47 were asymptomatic. Antibody responses were markedly attenuated in OCR compared with other groups (p ≤0.0001). T-cell responses (IFNγ) were decreased in S1P (p = 0.03), increased in natalizumab (p <0.001), and similar in other DMTs, including OCR. Cellular and humoral responses were moderately correlated in both OCR (r = 0.45, p = 0.0002) and non-OCR (r = 0.64, p <0.0001). Immune responses did not differ by race/ethnicity. Coronavirus disease 2019 (COVID-19) clinical course was mostly non-severe and similar across DMTs; 7% (9/130) were hospitalized. INTERPRETATION: DMTs had differential effects on humoral and cellular immune responses to SARS-CoV-2 infection. Immune responses did not correlate with COVID-19 clinical severity in this relatively young and nondisabled group of patients with MS. ANN NEUROL 2022;91:782-795.

Anti-SARS-CoV-2 T-stem cell memory persists in ocrelizumab-treated MS patients.

BACKGROUND: Development of long-lasting anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) T-cell responses in persons with multiple sclerosis (pwMS) treated with ocrelizumab is questioned. OBJECTIVE: Investigate antiviral T-cell responses after infection with SARS-CoV-2 in ocrelizumab-treated pwMS. Control groups included ocrelizumab-treated pwMS without SARS-CoV-2 infection, and non-MS individuals with and without SARS-CoV-2 infection. METHODS: Peripheral blood mononuclear cells were stimulated with SARS-CoV-2 peptide pools and T-cell reactivity was assessed by ELISPOT for interferon (IFN)-γ detection, and by multiparametric fluorescence-activated cell sorting (FACS) analyses for assessment and characterization of T-cell activation. RESULTS: ELISPOT assay against the spike and the N protein of SARS-CoV-2 displayed specific T-cell reactivity in 28/29 (96%) pwMS treated with ocrelizumab and infected by SARS-CoV-2, similar to infected persons without MS. This reactivity was present 1 year after infection and independent from the time of ocrelizumab infusion. FACS analysis following stimulation with SARS-CoV-2 peptide pools showed the presence of activation-induced markers (AIMs) in both CD4+ and CD8+ T-cell subsets in 96% and 92% of these individuals, respectively. Within naïve AIM+ CD4+ and CD8+ T-cells, we detected T memory stem cells, suggesting the acquisition of long-term memory. CONCLUSIONS: B-cell depletion using ocrelizumab does not impair the development of long-lasting anti-SARS-CoV-2 T-cell responses.

DNA threads released by activated CD4+ T lymphocytes provide autocrine costimulation.

The extrusion of DNA traps contributes to a key mechanism in which innate immune cells clear pathogens or induce sterile inflammation. Here we provide evidence that CD4+ T cells, a critical regulator of adaptive immunity, release extracellular threads of DNA on activation. These DNA extrusions convey autocrine costimulatory signals to T lymphocytes and can be detected in lymph nodes isolated during the priming phase of experimental autoimmune encephalomyelitis (EAE), a CD4+ T cell-driven mouse model of multiple sclerosis. Pharmacologic inhibition of mitochondrial reactive oxygen species (mtROS) abolishes the extrusion of DNA by CD4+ T cells, reducing cytokine production in vitro and T cell priming against myelin in vivo. Moreover, mtROS blockade during established EAE markedly ameliorates disease severity, dampening autoimmune inflammation of the central nervous system. Taken together, these experimental results elucidate a mechanism of intrinsic immune costimulation mediated by DNA threads released by activated T helper cells, and identify a potential therapeutic target for such disorders as multiple sclerosis, neuromyelitis optica, and CD4+ T cell-mediated disorders.

Prolactin: Friend or Foe in Central Nervous System Autoimmune Inflammation?

The higher prevalence of multiple sclerosis (MS) in females, along with the modulation of disease activity observed during pregnancy and the post-partum period, has suggested a hormonal influence in MS. Even if prolactin (PRL) does not belong to the sex hormones family, its crucial role in female reproduction and lactation has prompted great efforts to understand if PRL could represent a gender factor in the pathogenesis of MS and experimental autoimmune encephalomyelitis (EAE), the animal model for this disease. Extensive literature has documented a remarkable immune-stimulating potential for this hormone, indicating PRL as a disease-promoting factor in MS and EAE. However, recent work has pointed out that PRL is endowed with important neuroprotective and remyelinating properties and has encouraged a reinterpretation of the involvement of this hormone in MS. In this review we summarize both the protective functions that PRL exerts in central nervous system tissue as well as the inflammatory activity of this hormone in the context of autoimmune responses against myelin. Last, we draw future lines of research that might help to better clarify the impact of PRL on MS pathology.

Prolactin is not required for the development of severe chronic experimental autoimmune encephalomyelitis.

Predominance of multiple sclerosis (MS) in women, reductions of disease flares during pregnancy, and their increase in the postpartum period have suggested a hormonal influence on MS activity. The hormone prolactin (PRL) has long been debated as a potential immune-stimulating factor in several autoimmune disorders, including MS and its animal model experimental autoimmune encephalomyelitis (EAE). However, to date, no data clearly ascribe a pathogenic role to PRL in these diseases. Using PRL receptor-deficient (Prlr(-/-)) and PRL-deficient (Prl(-/-)) mice, we show that PRL plays a redundant role in the development of chronic EAE. In Prlr(-/-) and Prl(-/-) mice, EAE developed with a delayed onset compared with littermate control mice, but with full clinical severity. In line with the clinical outcome, T cell proliferation and production of IFN-γ, IL-17A, and IL-6 induced by myelin Ag were delayed in Prlr(-/-) and Prl(-/-) mice. Ag-specific IgG Ab responses were not affected by PRLR or PRL deficiency. We also show that mouse lymph node cells and purified CD4(+) T cells express transcript for Prlr, but not for Prl. These results reveal that PRL does not play a central role in the development of chronic EAE and optimal Th1 and Th17 responses against myelin. Moreover, they also rule out a possible contribution of PRL secreted by immune cells to the modulation of autoreactive T cell response in this model.

Accuracy of a questionnaire for identifying respiratory allergies in epidemiological studies.

BACKGROUND: The assessment of allergic asthma (AA) and allergic rhinitis (AR) in epidemiological studies is often challenging. We performed a cross-sectional study to test the accuracy of a Questionnaire aimed at Identifying subjects with Respiratory Allergy (QIRA) in a simple and fast way. METHODS: One hundred-thirty subjects, 18-76 years of age, admitted consecutively at the Allergy Center of the Niguarda Ca` Granda Hospital of Milan were included. The questionnaire (index test) investigated the presence of AA and AR with seven questions enquiring history of symptoms, diagnosis made by a doctor, allergy tests performed, and treatments. After completing the questionnaire, all subjects were subsequently diagnosed by an allergist (reference standard). RESULTS: The accuracy of the questionnaire for the diagnosis of AA and AR was high (sensitivity 94.7% [95% confidence interval CI: 74.0-99.9] and specificity 99.1% [95% CI 95.1-100.0] for AA; sensitivity 82.8% [95% CI 71.3-91.1] and specificity 98.5% [95% CI 91.8-100.0] for AR). CONCLUSION: The questionnaire significantly distinguished subjects with respiratory allergy from those without. The QIRA represents a valid and accurate tool for classifying subjects as having or not AA and/or AR in epidemiological studies.

Long-Term Immune Response Profiles to SARS-CoV-2 Vaccination and Infection in People with Multiple Sclerosis on Anti-CD20 Therapy.

Our objective was to analyze longitudinal cellular and humoral immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in people with multiple sclerosis (pwMS) on B-cell depleting treatment (BCDT) compared to pwMS without immunotherapy. We further evaluated the impact of COVID-19 infection and vaccination timing. PwMS (n = 439) on BCDT (ocrelizumab, rituximab, ofatumumab) or without immunotherapy were recruited for this prospective cohort study between June 2021 and June 2022. SARS-CoV-2 spike-specific antibodies and interferon-γ release of CD4 and CD8 T-cells upon stimulation with spike protein peptide pools were analyzed at different timepoints (after primary vaccination, 3 and 6 months after primary vaccination, after booster vaccination, 3 months after booster). Humoral response to SARS-CoV-2 was consistently lower whereas T-cell response was higher in patients with BCDT compared to controls. Cellular and humoral responses decreased over time after primary vaccination and increased again upon booster vaccination, with significantly higher antibody titers after booster than after primary vaccination in both untreated and B-cell-depleted pwMS. COVID-19 infection further led to a significant increase in SARS-CoV-2-specific responses. Despite attenuated B-cell responses, a third vaccination for patients with BCDT seems recommendable, since at least partial protection can be expected from the strong T-cell response. Moreover, our data show that an assessment of T-cell responses may be helpful in B-cell-depleted patients to evaluate the efficacy of SARS-CoV-2 vaccination.

Anti-SARS-CoV-2 monoclonal antibodies for the treatment of mild-to-moderate COVID-19 in multiple sclerosis: A retrospective cohort study.

BACKGROUND: The use and potential benefit of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) monoclonal antibodies (mAbs) for the treatment of mild-to-moderate coronavirus disease 2019 (COVID-19) in people living with multiple sclerosis (pwMS) remains poorly studied. The objective of this study is to describe the therapeutic use of anti-SARS-CoV-2 mAbs among pwMS. METHODS: This retrospective cohort study used electronic medical records data from the TriNetX Dataworks USA Network and included adult pwMS, diagnosed with COVID-19, who received anti-SARS-CoV-2 mAbs in the outpatient setting between November 2020 and April 2022. We analyzed COVID-19 severity at anti-SARS-CoV-2 mAb initiation and up to 30 days, stratified by before/after emergence of Omicron variant and by disease-modifying therapy (DMT). RESULTS: The study included 434 pwMS treated with anti-SARS-CoV-2 mAbs for mild-to-moderate COVID-19, including 270 patients before and 174 after Omicron emergence. Most pwMS were female (80.2%), mean age (SD) was 51.5 (12.5) years. Two-hundred-and-five patients were on DMTs, 51% of whom received anti-CD20s. One patient with moderate COVID-19 was hospitalized whilst receiving glatiramer acetate. No patients required intensive care and there were no deaths. COVID-19 outcomes were comparable following anti-SARS-CoV-2 mAb therapy in patients receiving different DMTs. CONCLUSION: Anti-SARS-CoV-2 mAb treatment for pwMS with mild-to-moderate COVID-19 may reduce the risk of COVID-19-related hospitalization and death.

Gender-based blood transcriptomes and interactomes in multiple sclerosis: involvement of SP1 dependent gene transcription.

In this study we investigated the contribution of gender to global gene expression in peripheral blood mononuclear cells from multiple sclerosis (MS) patients and healthy controls. We observed that, in contrast to the conventional approach, gender-based case-control comparisons resulted in genelists with significantly reduced heterogeneity in human populations. In addition, MS was characterized by significant changes both in the quantity and in the quality of the sex-specific genes. Application of stringent statistics defined gender-based signatures which classified a second independent MS population with high precision. The global unsupervised cluster analyses for 60 subjects showed that 29/31 female and 27/29 male samples were properly identified. Notably, MS was associated in women and in men with distinct gene signatures which however shared several molecular functions, biological processes and interactors. Issues regarding epigenetic control of gene expression appeared as the main common theme for disease, with a central role for the functional modules related to histone deacetylase, NF-kappaB and androgen receptor signaling. Moreover, in silico analyses predicted that the differential expression in MS women and men were depending on the transcription factor SP1. Specific targeting of this pathway by the bis-anthracycline WP631 impaired T cell responses in vitro and in vivo, and reduced the incidence and the severity of experimental autoimmune encephalomyelitis, indicating that SP1 dependent gene transcription sustains neuroinflammation. Thus, the gender-based approach with its reduced heterogeneity and the systems biology tools with the identification of the molecular and functional networks successfully uncovered the differences but also the commonalities associated to multiple sclerosis in women and men. In conclusion, we propose gender-based systems biology as a novel tool to gain fundamental information on disease-associated functional processes.

Mast cells in the pathogenesis of multiple sclerosis and experimental autoimmune encephalomyelitis.

Mast cells (MCs) are best known as key immune players in immunoglobulin E (IgE)-dependent allergic reactions. In recent years, several lines of evidence have suggested that MCs might play an important role in several pathological conditions, including autoimmune disorders such as multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), an animal model for MS. Since their first description in MS plaques in the late 1800s, much effort has been put into elucidating the contribution of MCs to the development of central nervous system (CNS) autoimmunity. Mouse models of MC-deficiency have provided a valuable experimental tool for dissecting MC involvement in MS and EAE. However, to date there is still major controversy concerning the function of MCs in these diseases. Indeed, although MCs have been classically proposed as having a detrimental and pro-inflammatory role, recent literature has questioned and resized the contribution of MCs to the pathology of MS and EAE. In this review, we will present the main evidence obtained in MS and EAE on this topic, and discuss the critical and controversial aspects of such evidence.

Timing of SARS-CoV-2 Vaccination Matters in People With Multiple Sclerosis on Pulsed Anti-CD20 Treatment.

BACKGROUND AND OBJECTIVES: Our objective was to investigate cellular and humoral immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in a cohort of people with multiple sclerosis (pwMS) on pulsed B-cell-depleting treatment (BCDT). In particular, we intended to evaluate a possible association between immune responses and the timing of vaccination under BCDT. METHODS: We conducted a cross-sectional study among pwMS on pulsed BCDT or without disease-modifying treatment after completed SARS-CoV-2 vaccination. Samples were collected during routine clinical visits at the Multiple Sclerosis Center Dresden, Germany, between June 2021 and September 2021. Blood was analyzed for SARS-CoV-2 spike protein-specific antibodies and interferon-γ release of CD4 and CD8 T cells on stimulation with spike protein peptide pools. Lymphocyte subpopulations and total immunoglobulin levels in the blood were measured as part of clinical routine. RESULTS: We included 160 pwMS in our analysis, comprising 133 pwMS on BCDT (n = 132 on ocrelizumab and n = 1 on rituximab) and 27 without disease-modifying treatment. Humoral and cellular anti-SARS-CoV-2 responses were reciprocally regulated by the time between the last BCDT cycle and vaccination. Although antibody responses increased with prolonged intervals between the last BCDT cycle and vaccination, CD4 and CD8 T-cell responses were higher in pwMS vaccinated at early time points after the last BCDT cycle compared with untreated pwMS. T-cellular vaccination responses correlated with total, CD3 CD4, and partly with CD3 CD8 lymphocyte counts. Humoral responses correlated with CD19 lymphocyte counts. Status post coronavirus disease 2019 infection led to significantly increased SARS-CoV-2-specific T-cell and antibody responses. DISCUSSION: Delaying BCDT is currently discussed as a strategy to optimize humoral responses to SARS-CoV-2 vaccination. However, T cells represent an important line of defense against SARS-CoV-2 infection as well, especially in light of emerging variants of concern. We observed enhanced CD4 and CD8 T-cellular responses in pwMS receiving vaccination at early time points after their last BCDT cycle. These data may influence clinical decision making with respect to vaccination strategies in patients receiving BCDT.

Clinical outcomes of COVID-19 in patients with multiple sclerosis treated with ocrelizumab in the pre- and post-SARS-CoV-2 vaccination periods: Insights from Israel.

The coronavirus disease 2019 (COVID-19) pandemic caused challenges in the management of patients living with multiple sclerosis (PLwMS). We investigated the occurrence and severity of COVID-19 infection post-vaccination among PLwMS treated with ocrelizumab and enrolled in the Maccabi Health Services (MHS) (n = 289) or followed at the Hadassah Medical Center (HMC) (n = 80) in Israel. Most patients were fully vaccinated (MHS n = 218; HMC n = 76) and confirmed infection post-vaccination was low (3.7% and 2.6%, respectively). MHS: infection was more severe (hospitalization/intensive care unit/death) in non-vaccinated (33.3%) vs vaccinated patients (25%). HMC: one vaccinated patient required hospitalization with COVID-19 vs two unvaccinated patients. These data from two Israel cohorts suggest that occurrence of COVID-19 after mRNA vaccination is low and limited in severity.

Exacerbated experimental autoimmune encephalomyelitis in mast-cell-deficient Kit W-sh/W-sh mice.

Mast cell (MC)-deficient c-Kit mutant Kit(W/W-v) mice are protected against experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, suggesting a detrimental role for MCs in this disease. To further investigate the role of MCs in EAE, we took advantage of a recently characterized model of MC deficiency, Kit(W-sh/W-sh). Surprisingly, we observed that myelin oligodendrocyte glycoprotein (MOG)(35-55)-induced chronic EAE was exacerbated in Kit(W-sh/W-sh) compared with Kit(+/+) mice. Kit(W-sh/W-sh) mice showed more inflammatory foci in the central nervous system (CNS) and increased T-cell response against myelin. To understand whether the discrepant results obtained in Kit(W-sh/W-sh) and in Kit(W/W-v) mice were because of the different immunization protocols, we induced EAE in these two strains with varying doses of MOG(35-55) and adjuvants. Although Kit(W-sh/W-sh) mice exhibited exacerbated EAE under all immunization protocols, Kit(W/W-v) mice were protected from EAE only when immunized with high, but not low, doses of antigen and adjuvants. Kit(W-sh/W-sh) mice reconstituted systemically, but not in the CNS, with bone marrow-derived MCs still developed exacerbated EAE, indicating that protection from disease could be exerted by MCs mainly in the CNS, and/or by other cells possibly dysregulated in Kit(W-sh/W-sh) mice. In summary, these data suggest to reconsider MC contribution to EAE, taking into account the variables of using different experimental models and immunization protocols.

The matricellular protein SPARC supports follicular dendritic cell networking toward Th17 responses.

Lymphnode swelling during immune responses is a transient, finely regulated tissue rearrangement, accomplished with the participation of the extracellular matrix. Here we show that murine and human reactive lymph nodes express SPARC in the germinal centres. Defective follicular dendritic cell networking in SPARC-deficient mice is accompanied by a severe delay in the arrangement of germinal centres and development of humoral autoimmunity, events that are linked to Th17 development. SPARC is required for the optimal and rapid differentiation of Th17 cells, accordingly we show delayed development of experimental autoimmune encephalomyelitis whose pathogenesis involves Th17. Not only host radioresistant cells, namely follicular dendritic cells, but also CD4(+) cells are the relevant sources of SPARC, in vivo. Th17 differentiation and germinal centre formation mutually depend on SPARC for a proper functional crosstalk. Indeed, Th17 cells can enter the germinal centres in SPARC-competent, but not SPARC-deficient, mice. In summary, SPARC optimizes the changes occurring in lymphoid extracellular matrix harboring complex interactions between follicular dendritic cells, B cells and Th17 cells.

Mast cells counteract regulatory T-cell suppression through interleukin-6 and OX40/OX40L axis toward Th17-cell differentiation.

The development of inflammatory diseases implies inactivation of regulatory T (Treg) cells through mechanisms that still are largely unknown. Here we showed that mast cells (MCs), an early source of inflammatory mediators, are able to counteract Treg inhibition over effector T cells. To gain insight into the molecules involved in their interplay, we set up an in vitro system in which all 3 cellular components were put in contact. Reversal of Treg suppression required T cell-derived interleukin-6 (IL-6) and the OX40/OX40L axis. In the presence of activated MCs, concomitant abundance of IL-6 and paucity of Th1/Th2 cytokines skewed Tregs and effector T cells into IL-17-producing T cells (Th17). In vivo analysis of lymph nodes hosting T-cell priming in experimental autoimmune encephalomyelitis revealed activated MCs, Tregs, and Th17 cells displaying tight spatial interactions, further supporting the occurrence of an MC-mediated inhibition of Treg suppression in the establishment of Th17-mediated inflammatory responses.

Prolonged survival and decreased abnormal movements in transgenic model of Huntington disease, with administration of the transglutaminase inhibitor cystamine.

An expanded polyglutamine domain in huntingtin underlies the pathogenic events in Huntington disease (HD), characterized by chorea, dementia and severe weight loss, culminating in death. Transglutaminase (TGase) may be critical in the pathogenesis, via cross-linking huntingtin. Administration of the TGase competitive inhibitor, cystamine, to transgenic mice expressing exon 1 of huntingtin containing an expanded polyglutamine repeat, altered the course of their HD-like disease. Cystamine given intraperitoneally entered brain where it inhibited TGase activity. When treatment began after the appearance of abnormal movements, cystamine extended survival, reduced associated tremor and abnormal movements and ameliorated weight loss. Treatment did not influence the appearance or frequency of neuronal nuclear inclusions. Unexpectedly, cystamine treatment increased transcription of one of the two genes shown to be neuroprotective for polyglutamine toxicity in Drosophila, dnaj (also known as HDJ1 and Hsp40 in humans and mice, respectively). Inhibition of TGase provides a new treatment strategy for HD and other polyglutamine diseases.

Gene-microarray analysis of multiple sclerosis lesions yields new targets validated in autoimmune encephalomyelitis.

Microarray analysis of multiple sclerosis (MS) lesions obtained at autopsy revealed increased transcripts of genes encoding inflammatory cytokines, particularly interleukin-6 and -17, interferon-gamma and associated downstream pathways. Comparison of two poles of MS pathology--acute lesions with inflammation versus 'silent' lesions without inflammation--revealed differentially transcribed genes. Some products of these genes were chosen as targets for therapy of experimental autoimmune encephalomyelitis (EAE) in mice. Granulocyte colony-stimulating factor is upregulated in acute, but not in chronic, MS lesions, and the effect on ameliorating EAE is more pronounced in the acute phase, in contrast to knocking out the immunoglobulin Fc receptor common gamma chain where the effect is greatest on chronic disease. These results in EAE corroborate the microarray studies on MS lesions. Large-scale analysis of transcripts in MS lesions elucidates new aspects of pathology and opens possibilities for therapy.

Understanding the impacts of COVID-19 pandemic in people with multiple sclerosis treated with ocrelizumab.

The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to major challenges in the therapeutic management of patients living with multiple sclerosis (PLwMS), particularly regarding the use of disease-modifying therapies. Despite an extraordinary scientific effort to study SARS-CoV-2 in PLwMS, the heterogeneity of COVID-19 manifestations, immunological mechanisms induced by the natural infection or the vaccines, and the extent of protection through the vaccines, major knowledge gaps remain. Here, we describe the scientific evidence generation plan developed by Roche/Genentech to better understand the impact of the COVID-19 pandemic in PLwMS treated with the B-cell depleting monoclonal antibody ocrelizumab.

CD8+ T cells specific for cryptic apoptosis-associated epitopes exacerbate experimental autoimmune encephalomyelitis.

The autoimmune immunopathology occurring in multiple sclerosis (MS) is sustained by myelin-specific and -nonspecific CD8+ T cells. We have previously shown that, in MS, activated T cells undergoing apoptosis induce a CD8+ T cell response directed against antigens that are unveiled during the apoptotic process, namely caspase-cleaved structural proteins such as non-muscle myosin and vimentin. Here, we have explored in vivo the development and the function of the immune responses to cryptic apoptosis-associated epitopes (AEs) in a well-established mouse model of MS, experimental autoimmune encephalomyelitis (EAE), through a combination of immunization approaches, multiparametric flow cytometry, and functional assays. First, we confirmed that this model recapitulated the main findings observed in MS patients, namely that apoptotic T cells and effector/memory AE-specific CD8+ T cells accumulate in the central nervous system of mice with EAE, positively correlating with disease severity. Interestingly, we found that AE-specific CD8+ T cells were present also in the lymphoid organs of unprimed mice, proliferated under peptide stimulation in vitro, but failed to respond to peptide immunization in vivo, suggesting a physiological control of this response. However, when mice were immunized with AEs along with EAE induction, AE-specific CD8+ T cells with an effector/memory phenotype accumulated in the central nervous system, and the disease severity was exacerbated. In conclusion, we demonstrate that AE-specific autoimmunity may contribute to immunopathology in neuroinflammation.

COVID-19 in ocrelizumab-treated people with multiple sclerosis.

BACKGROUND: There are limited data on the impact of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on people with multiple sclerosis (MS). OBJECTIVE: To better understand SARS-CoV-2 infection in ocrelizumab-treated people with MS. METHODS: Internal Roche/Genentech data sources: Cases of COVID-19 from ongoing Roche/Genentech clinical trials and from post-marketing use of ocrelizumab until July 31, 2020 were identified and assessed using descriptive statistics. External real-world data (RWD) source: An MS COVID-19 cohort and an ocrelizumab-treated MS COVID-19 cohort were identified and assessed from the OPTUMⓇ de-identified COVID-19 electronic health record (EHR) database. RESULTS: Roche/Genentech clinical trial data: There were 51 (1.3%) suspected or confirmed cases of COVID-19 identified from 4,000 patients ongoing in 10 Roche/Genentech clinical trials. Of these, 26 (51%) were confirmed COVID-19 and 25 (49%) were suspected COVID-19. Sixteen (31.4%) patients were hospitalized. COVID-19 severity was mild to moderate in most patients (35, 68.6%). Ten (19.6%) patients had severe disease and there were three (5.9%) fatal cases. Most patients (43, 84.3%) recovered or were recovering. There was no association apparent between duration of exposure to ocrelizumab and COVID-19. Among COVID-19 patients with previous serum immunoglobulin status (27/51, 52.9%), all (27/27, 100%) had IgG levels within the normal range. Roche/Genentech post-marketing safety database data: There were 307 post-marketing cases of COVID-19 in the Roche/Genentech global safety database. Of these, 263 (85.7%) were confirmed and 44 (14.3%) were suspected COVID-19. 100 (32.6%) patients were hospitalized. COVID-19 was asymptomatic, mild or moderate in 143 (46.6%) patients, severe in 52 (16.9%) patients, and critical in 15 (4.9%) patients. There were 17 (5.5%) fatal cases. Information on severity was not reported in 80 (26.1%) cases. Most patients (211, 68.7%) recovered or were recovering at the time of the report. External RWD data source: As of July 13, 2020, the OPTUMⓇ database included EHRs for almost 1.2 million patients with suspected COVID-19, 130,500 of whom met the criteria for confirmed/clinically diagnosed COVID-19. A total of 357 patients with MS with confirmed COVID-19 were identified. Forty-eight (13.4%) were treated with ocrelizumab, of whom 12 (25.0%) were hospitalized and one died (2.1%). Similar rates of hospitalization, invasive ventilation, and death were observed in the ocrelizumab-treated and non-ocrelizumab-treated MS cohorts. Across the Roche/Genentech and RWD sources assessed, age, male sex, and the presence of comorbidities such as hypertension were associated with a more severe disease course of COVID-19. There was a higher number of comorbidities present in hospitalized versus non-hospitalized patients. CONCLUSIONS: This assessment provides evidence that COVID-19 in ocrelizumab-treated people with MS is predominantly mild to moderate in severity with most patients not requiring hospitalization; in line with data reported from the general population and MS datasets. Risk factors known to be associated with severe COVID-19 outcomes in the general population also appear to influence COVID-19 severity in ocrelizumab-treated people with MS. Case fatality rates for ocrelizumab-treated people with MS were within published ranges for the general population and other MS cohorts.