ABSTRACT
Introduction: Some multiple sclerosis (MS) disease-modifying therapies (DMTs) are associated with blunted humoral vaccination responses, but relevance for SARS-CoV-2 infection is unclear. Objective(s): To determine SARS-CoV-2 exposure rates and formation of antibody memory among participants of the COMparison Between All immunoTherapies for MS (COMBAT-MS;NCT03193866) and the Immunomodulation and MS Epidemiology (IMSE) studies. Aim(s): To determine SARS-CoV2 serological response of people living with MS (pwMS). Method(s): Using a multiplex bead-based assay we determined SARS-CoV-2 spike and nucleocapsid antibody levels in 3,723 pwMS in paired serum samples (n=7,157) donated prior (<January 31st 2020) and during the pandemic (July-October 2020);16.6% had natalizumab, 6.4% fingolimod, 9.7% dimethyl fumarate, 1.9% interferon beta, 50.4% rituximab, 1.4% cladribine, 7.6% other DMTs, and 6.1% were untreated. Median fluorescent intensity (MFI) and bead-count were determined for spike and nucleocapsid antibodies, and samples were regarded as positive only when reactive to both viral antigens. Hazard ratios, from multivariable Cox regression models, were derived to assess association between antibody levels above cut-off for each antigen, comparing exposure to rituximab or fingolimod at time of sampling vs. other reference DMTs. All models were adjusted for age, sex, treatment center, time since reported infection, MS severity, disease duration, and number of previous DMTs. Result(s): Specificity and sensitivity of the assay for SARS-CoV-2 was 100% and 99.7%, respectively. The proportion of positive samples for SARS-CoV-2 differed moderately across DMTs with the highest values among cladribine-treated (7.4%) and the lowest number among rituximab-treated pwMS (3.9%). Similarly, the proportion of positive cases not reported in the Swedish MS registry varied from 100% for cladribine to 33.3% among untreated pwMS. Comparing levels of antibodies titers showed that levels were lower among those treated with rituximab or fingolimod vs interferon treated pwMS. Point estimates indicated a similar trend comparing rituximab or fingolimod vs untreated pwMS. Conclusion(s): Overall rates of SARS-CoV-2 antibody positivity after the first COVID-19 wave differed only moderately across DMTs, while antibody levels were lower with rituximab or fingolimod compared to interferon-treated pwMS. This indicates quantitative rather than qualitative differences in the humoral response to infection.
ABSTRACT
Introduction: The new SARS-CoV-2-mRNA-vaccines provide protection against severe COVID-19 infection. Disease modifying therapies (DMTs) for treatment of persons with multiple sclerosis (pwMS) differently impact humoral and cellular immunity and therefore can diminish vaccination outcomes. Thus, it is crucial to investigate the influence of different DMTs on the immune response after SARS-CoV-2 vaccination of pwMS. Objective(s): To investigate antibody and T-cell responses after SARS-CoV-2-vaccination in pwMS treated with different DMTs. Method(s): We studied antibody and T-cell responses in pwMS 4 and 12 weeks after the second dose of mRNA-vaccination against SARS-CoV-2. The results were compared to baseline samples taken before the first dose of SARS-CoV-2-vaccination. We screened and included 148 pwMS treatedwith natalizumab (n=23), dimethylfumarate (n=24), fingolimod (n=39), cladribine (n=31), alemtuzumab (n=17) and teriflunomide (n=14). Healthy controls (HC) (n=43) were used as a comparison. To evaluate humoral immune responses, IgG reactivity was measured towards three different SARS-CoV-2 antigens using a multiplex bead assay: full-length spike glycoprotein (spike S1S2 foldon), spike S1 domain and the nucleocapsid protein C-terminal domain (Nucleocapsid C). Furthermore, the antibody data allowed us to distinguish pwMS who had been vaccinated after a previous SARS-CoV-2-infection. Cellular immune responses were studied using a Fluorospot assay measuring IFNy and IL-13 T-cell responses to the spike S1 domain and Nucleocapsid C. Result(s): Humoral responses to vaccination were comparable between HC and pwMS treated with natalizumab, dimethylfumarate, cladribine, alemtuzumab and teriflunomide, but suppressed with fingolimod. In addition, T-cell responses were nearly absent in the fingolimod group and moderately reduced in the cladribine group. Conclusion(s): In this comprehensive study of both antibody and cellular responses to SARS-CoV-2-vaccination in pwMS on different DMTs, fingolimod was associated with abrogated responses in both aspects, while cladribine-treated individuals displayed reduced cellular response only. These findings are of relevance for risk mitigation strategies and vaccination recommendations for pwMS.
ABSTRACT
In the last decade, the increased use of anti-CD20 treatment in patients with multiple sclerosis (pwMS) has been highly effective in reducing relapse rates and new inflammatory disease activity. A growing amount of evidence has implicated CD20+ T cells as the disease pathogenic cells and possible targets of anti-CD20 agents. Aim: We here aimed to characterise CD20+ T cells in pwMS who have been treated with rituximab and extended the dosing interval due to the COVID-19 pandemic and compared them to other treatments and healthy donors. Method: We characterised CD20+ T cells using flow cytometry in a cohort of pwMS with blood sampling 437±214 days after anti-CD20 treatment (Rituximab, n=47;Ocrelizumab, n=4) and compared with other disease modifying treatments (DMT, n=18) and healthy donors (HD, n=15). Results: B cells constituted 2.82±1.58 % of peripheral blood mononuclear cells from anti-CD20 treated pwMS at time of sampling. We neither found a correlation between time since last dose and levels of CD20+ T cells, nor differences in CD20+ T-cell percentages in anti-CD20 treated pwMS as compared to other DMTs and HD. In addition, independently of the treatment, approximately 40% of CD20+ T cells displayed a CD4+ phenotype enriched for memory cells. Furthermore, CD4+CD20+ T cells in rituximab-treated pwMS included 43.9±19.9 % PD1+, 15.9±10.5 % follicular helper T cells (Tfh), 4.8±4.4 % regulatory T cells (Treg) and 71.9±19.1 % memory cells. Memory CD4+CD20+ T cells were, based on chemokine receptors CXCR3 and CCR6 expression, divided into 33.9±15.5 % Th1, 13.3±7.7 % Th2, 17.5±8.2 % Th17 and 35.1±10.8 % Th1/17. Of note, rituximabtreated pwMS displayed significantly higher levels of Treg cells among CD20+ T-cell populations as compared to HD (4.8% vs 2.3%;p=0.0423). No evidence of clinical rebound disease activity was observed in the cohort despite presence of CD20+ T cells. Conclusion: Our findings suggest that CD20+ T cells at B-cell reconstitution after rituximab treatment do not induce rebound disease activity. Further studies are needed to molecularly define and contrast CD20+ T cells being present in pwMS at treatment start and after B-cell reconstitution, respectively, in order to better determine their role in the immunopathogenesis of MS.
ABSTRACT
Introduction: B-cell depleting therapies used in multiple sclerosis (MS) have been associated with higher risk of severe COVID- 19. However, more precise knowledge of how B-cell depletion affects development of humoral and cellular immunity to viruses, in particular to SARS-CoV-2, is still limited. Objectives: To determine humoral and cellular SARS-CoV-2 responses after COVID-19 infection or vaccination in MS patients treated with different disease modulatory therapies (DMTs), with a focus on B-cell depleting therapies. Aims: Understand the impact of B-cell depleting therapy on the ability to develop a specific SARS-CoV-2 immunological memory after a COVID-19 infection or vaccination. Methods: We analyzed sera from subjects (n=2800) in an ongoing observational drug trial comprising multiple MS DMTs (COMBAT-MS;NCT03193866). In a single center subcohort (n=137, including healthy controls) enriched for COVID-19-like symptoms, samples for more detailed cellular analyses were obtained. Lastly, a small cohort of patients on B-cell depleting therapies were analyzed either before (n=4) or after (n=6) being vaccinated against SARS-CoV-2. Specific antibodies were determined with electro-chemiluminescence immunoassay and multiplex bead array. T-cell memory responses were determined by FluoroSpot and flow cytometry. Results: Data on humoral responses in the entire cohort will be included in the final presentation. The subcohort patients on B-cell depleting therapies were stratified into three different groups depending on B-cell status at onset of COVID-19-like symptoms;a) completely depleted (<0.01;B-cell count x 10-9/L, n=14), b) partially repleted (0.01-0.08;B-cell count x 10-9/L, n=7) or c) completely repleted (>0.08;B-cell count x 10-9/L, n=3). Within the three groups, 50%/71%, 86%/100% and 100%/100% developed a SARS-CoV-2 specific antibody/T-cell response, respectively. Furthermore, antibody titers were not significantly different from those on other DMTs or healthy controls, and SARS-CoV-2 specific T-cells also displayed functional similarity. Lastly, in the vaccination cohort, all patients displayed a specific T-cell response after vaccination although only 50% of them also developed a humoral response. Conclusions: These findings indicate that B-cell depletion does not prevent a specific immunological memory after a COVID-19 infection or vaccination against SARS-CoV-2, and patients that do not develop humoral immunity might still have a specific T-cell response. Further studies are needed to determine the correlation between immunological parameters and clinical immunity.