Effect of SARS-CoV-2 vaccination on natural killer cell responses in multiple sclerosis

Introduction: Anti-SARS-CoV2 vaccination induces specific Tand B-cell responses in healthy subjects (HS). In MS patients treated with anti-CD20 drugs, the antibody response is reduced or absent, whereas specific T-cell responses are maintained. It is not known whether and how vaccination affects innate responses mediated by natural killer (NK) cells in HS and in MS patients treated with anti-CD20 drugs. Objective(s): To evaluate whether and how NK cells contribute to the immune response following anti-SARS-CoV2 vaccination in HS and in ocrelizumab-treated MS patients Aims: The aims of this work were: 1) to evaluate the effects of anti-SARS CoV2 vaccination on the phenotype of NK cells from HS and from ocrelizumab-treated MS patients and 2) to evaluate how peptides from the SARS-CoV2 spike protein affect NK cell responses before and after anti-SARS-CoV2 vaccination. Method(s): We enrolled 21 MS patients treated with ocrelizumab and 20 HS. Peripheral blood mononuclear cells (PBMCs) were isolated from peripheral blood and stored under liquid nitrogen. Thawed PBMCs were cultured overnight in presence/absence of SARS-CoV2 peptides or peptides from the cytomegalovirus (CMV), with/without activating cytokines. Phenotype of NK cells through a 13-marker flow cytometry panel and intracellular production of IFN-gamma were evaluated after culture. Result(s): Findings: 1) Vaccination increased the proportion of CD56dim NK cells in HS and MS patients. CD56posCD16neg NK cells, more abundant in MS patients before vaccination, decreased thereafter. Lower pre-vaccination activation capability of NK cells from MS patients compared to HS in response to stimulus with cytokines was reverted by vaccination. 2) Before vaccination, peptides from the SARS-CoV2 protein downregulated the production of IFN- gamma from NK cells of HS, but not ocrelizumabtreated MS patients, who had significantly lower baseline IFN-gamma NK cells 3) After vaccination, peptides from the SARS-CoV2 protein did not affect the production of IFN- gamma from NK cells of HS. Conclusion(s): The results of this work demonstrate anti-SARSCoV2 vaccination increases the proportion of effector CD56dim NK cells in HS and ocrelizumab-treated patients. Spike peptides inhibit the function of NK cells from HS before, but not after vaccination. Such phenomenon may contribute to the pathogenicity of SARS-CoV2 in unvaccinated subjects.

Effect of SARS-CoV-2 mRNA vaccination in multiple sclerosis patients treated with disease modifying therapies

Introduction: In patients with Multiple Sclerosis (pwMS) disease- modifying therapies (DMTs) are known to affect immune response to antigens and possibly to SARS-CoV2 vaccine. Therefore, post-vaccination serological assessments are needed to evaluate the effect of the vaccine on SARS-CoV-2 antibody response. Objectives and aims: We designed a prospective multicenter cohort study enrolling pwMS who were scheduled for SARSCov- 2 vaccination with mRNA vaccines (BNT162b2, Pfizer/ BioNTech, Inc or mRNA-1273, Moderna Tx, Inc) to evaluate their effect on SARS-CoV-2 antibody response. Methods: A blood collection for the measure of SARS-CoV-2 antibody before the first vaccine dose and 4 weeks after the second dose was planned, with a centralized and blinded serological assessment (electrochemiluminescence immunoassay, ECLIA, Roche Diagnostics). Results: Preliminary data were collected on 780 pwMS (76% BNT162b2 and 24% mRNA-1273) who had pre- and 4-week post-vaccination blood assessments. 87 (11.2%) were untreated, 154 (19.7%) on ocrelizumab, 25 (3.2%) on rituximab, 85 (10.9%) on fingolimod, 25 (3.2%) on cladribine and 404 (51.7%) on other DMTs. 677 patients (86.8%) had detectable post-vaccination SARS-CoV-2 antibodies. At multivariate analysis, the antibody levels of patients on ocrelizumab (178-fold decrease, p<0.001), fingolimod (26-fold decrease, p<0.001) and rituximab (17-fold decrease, p<0.001) were significantly reduced as compared to untreated patients. Vaccination with mRNA-1273 resulted in a systematically 3.5-fold higher antibody level than with the BNT162b2 vaccine (p<0.001). Interpretation: In pwMS, anti-CD20 treatment and fingolimod led to a reduced humoral response to mRNA-based SARS-CoV-2 vaccines. As mRNA-1273 elicits 3.5-higher antibody levels than BNT162b2, this vaccine may be preferentially considered for patients under anti-CD20 treatment or fingolimod. Combining our data with those that will be produced by studying the cellular immune response to vaccines, and including clinical follow-up, will contribute to better define the most appropriate SARS-CoV-2 vaccine strategies in the context of DMTs and MS. At the time of the ECTRIMS presentation data on the full sample (about 2000 subjects) will be presented.

Personalizing ocrelizumab treatment in Multiple Sclerosis: What can we learn from Sars-Cov2 pandemic?

During SARS-CoV-2 pandemic, we adopted a personalized delayed protocol for ocrelizumab infusions in Relapsing Remitting Multiple Sclerosis (RRMS) patients according to the national recommendations. Out of the 83 RRMS patients whose infusion was scheduled between March and December 2020, 56 patients experienced a delay in treatment based on MS severity and SARS-CoV2 infection risk profile. In most cases, the immunophenotype was performed monthly to guide re-infusions. Specifically, B CD19 + cells repopulation rate was monitored. Mean infusion delay was 103,1 [SD 40,6] days, and none of the patients presented relapses or active disease at MRI at the end of the observation period. Treatment naïve status and the interval between immunophenotyping and the last ocrelizumab infusion were predictors of earlier B CD19 + cells repopulation. Two patients contracted SARS-CoV2 with complete recovery. Definitive data about Sars-Cov2 vaccine efficacy in patients treated with ocrelizumab are still lacking. Our findings suggest that a personalized treatment with a delayed infusion schedule does not compromise ocrelizumab short-term efficacy and may help to lengthen the therapeutic window for an effective response to SARS-CoV2 vaccine.

Treatment with ocrelizumab during SARS-CoV2 pandemic: Efficacy and safety outcomes

Background: Sars-Cov2 pandemic led neurologists to modify the therapeutic approach in Multiple Sclerosis (MS) care setting, especially with regard to immunodepleting treatments. Objectives: to describe management and outcome of MS patients (pts) treated with ocrelizumab (OCR) during Sars-Cov2 pandemic in the MS Center of University of Genoa. Methods: we collected data about pts scheduled to undergo OCR infusion from 1st March to 30th June 2020. Pts that previously underwent the first OCR infusion completed the induction cycle. No further OCR cycles during March and April 2020 were performed. Starting from May, we adopted an infusion scheme based on B-cell repopulation, differently applied for Relapsing Remitting (RR) and Progressive (P) pts. RRMS pts performed immunophenotype (IF) and received OCR infusion when B CD19+ cell count overcame the cut-off of 1%. Conversely, for PMS pts OCR infusions were delayed for 3 months. Then, PMS pts underwent OCR infusion based on B CD19+ cell monitoring. For pts with evidence of B CD19+ cells repopulation brain 3T MRI was planned before OCR re-infusion. Results: 77 MS pts were included [45 (58%) RRMS, 32 (41%) PMS;mean age 44.7 (SD: 11.1) years, mean disease duration 21.7 (22.3) years, mean number of previous DMT before OCR: 1.6 (1.6), mean number of previous OCR infusions 3.9 (SD 2.3). 11 (13.1%, 9 RR, 2 PP) of the 49 pts that performed a first IF presented B CD19+ cell repopulation and received OCR re-infusion, with a mean delay from scheduled infusion of 70 (48.9) days. The mean number of previous OCR infusions was 3.0 (1.2) and 3.1 (1.6) for pts with and without evidence of B-cell repopulation respectively. No effect of previous OCR infusions number on the probability to develop B CD19+ cell repopulation at the first IF was detected by ANCOVA analysis, correcting for the delay between the date of scheduled infusion and the date in which the first IF has been performed. Considering the global cohort, 1 pt presented a dubious sensory relapse with no evidence of radiological activity. None of the pts who performed brain MRI before OCR re-infusion showed new T2 or Gd+ enhancing lesions. 3 pts were infected by Sars- Cov2;2 of them needed hospitalization but recovered completely. Conclusions: the management of patients treated with OCR during Sars-Cov2 pandemic with a personalized infusion protocol based on B CD19+ cells repopulation was associated with good results in terms of efficacy and safety outcome.