Clinical rationale for the study: The course of COVID-19 in people with multiple sclerosis (PwMS) has been described, while the serological status after SARS-CoV-2 infection or vaccination, especially in patients treated with disease-modifying therapies (DMT), is still under investigation. This is a significant clinical problem, as certain DMTs may predispose to a severe course of viral infections.
Aim of the study: We analyzed the presence of antibodies against spike (S) and nucleocapsid (N) proteins of SARS-CoV-2 in relapsing-remitting PwMS treated with DMT, especially dimethyl fumarate, interferon beta, and glatiramer acetate, in a single multiple sclerosis (MS) centre in north-eastern Poland (the Department of Neurology, Medical University of Bialystok).
Material and methods: The presence of antibodies against S and N proteins in PwMS was assessed twice: on visit one (between May and June 2020) (n = 186) and on visit two (between May and June 2021) (n = 88). Samples were taken from 68 individuals on both visits. Demographic and clinical data was collected: duration of MS, Expanded Disability Status Scale Score (EDSS), type of DMT, history of COVID-19 (positive PCR or antigen test in the past), vaccination status, and the type of vaccine.
Results: It was shown that on visit one: 3.7% (n = 7) PwMS were positive for IgA against S protein (IgA-S), 3.2% (n = 6) for IgG against S (IgG-S) protein, and none of those examined was positive for IgG against N protein (IgG-N). On visit two, the most common detected antibodies were IgG-S (71.3%; n = 62), then IgA-S (65.1%; n = 55), and the least common was IgG-N (18.2%; n = 16). On visit two: 20.45% of PwMS had a history of a positive SARS-CoV-2 PCR or antigen test during the last year. By the time of visit two, 42.05% (n = 37) of patients who participated in visit two had been full-course vaccinated against COVID-19. It was demonstrated that vaccination against SARS-CoV-2 significantly induces the production of IgG-S and IgA-S (p < 0.0001), while no difference between vaccinated and unvaccinated patients was shown in the detection of IgG-N. There was no correlation between COVID-19 infection and antibodies against proteins S and N in the study group. Moreover, the presented study did not show any relationship between the ability to produce antibodies against the S protein with any of the used DMTs.
Conclusions and clinical implications: According to our study, PwMS treated with dimethyl fumarate, interferon beta, or glatiramer acetate can efficiently produce antibodies against SARS-CoV-2 both after infection and after vaccination.
Keywords: COVID-19; SARS-CoV-2; antibodies; disease-modifying therapies; multiple sclerosis; serology; vaccines.