ABSTRACT
Introduction: SARS-CoV-2 seroconversion rate after COVID-19 may be influenced by disease-modifying therapies (DMTs) in patients with multiple sclerosis (MS) or neuromyelitis optica spectrum disorders (NMO-SD). Objectives: To investigate the seroprevalence and the quantity of SARS-CoV-2 antibodies in a cohort of patients with MS or NMO-SD. Aims: To improve our knowledge of the impact of different DMTs on the immune response to SARS-COV2. Methods: Blood samples were collected in patients diagnosed with COVID-19 between February 19, 2020 and February 26, 2021. SARS-CoV-2 antibody positivity rates and Ig levels (anti-S IgG titer, anti-S IgA index, anti-N IgG index) were compared between DMTs groups. Multivariate logistic and linear regression models were used to estimate the influence of DMTs and other confounding variables on SARS-CoV-2 serological outcomes. Results: 119 patients (115 MS, 4 NMO, mean age: 43.0 years) were analyzed. Overall seroconversion rate was 80.6% within 5.0 (SD 3.4) months after infection. 20/21 (95.2%) patients without DMT and 66/77 (85.7%) patients on DMTs other than anti-CD20 had at least one SARS-CoV-2 Ig positivity, while this rate decreased to only 10/21 (47.6%) for patients on anti-CD20 (p < 0.001). Patients on anti-CD20 had a lower anti-S IgG titer (mean [SD], 1.4 [1.6]) relative to patients on other DMTs (2.4 [1.1]) or no DMT (2.7 [0.8] (p<0.001 by ANOVA). Being on anti-CD20 was associated with a decreased odd of positive serology (OR, 0.06 [95%CI, 0.01-0.59], p=0.01) independently from time to COVID-19, total IgG level, age, sex and COVID-19 severity. Time between last anti-CD20 infusion and COVID-19 was longer (mean [SD], 3.7 [2.0] months) in seropositive patients compared to seronegative patients (mean [SD], 1.9 [1.5] months, p=0.04). Serological data at 6 months follow-up after inclusion will be available and presented during the congress. Conclusions: SARS-CoV-2 antibody response was decreased in patients with MS or NMO-SD treated with anti-CD20 therapies. Monitoring long-term risk of reinfection and specific vaccination strategies in this population may be warranted.