COVID-19 and the Risk of Relapse in Multiple Sclerosis Patients: A Fight with No Bystander Effect?

Masoud Etemadifar; Nahad Sedaghat; Ali Aghababaee; Parisa K Kargaran; Mohammad Reza Maracy; Mazdak Ganjalikhani-Hakemi; Milad Rayani; Amir Parsa Abhari; Reza Khorvash; Mehri Salari; Hosein Nouri

doi:10.1016/j.msard.2021.102915

COVID-19 and the Risk of Relapse in Multiple Sclerosis Patients: A Fight with No Bystander Effect?

Mult Scler Relat Disord. 2021 Jun:51:102915. doi: 10.1016/j.msard.2021.102915. Epub 2021 Mar 20.

Affiliations

¹ Department of Neurosurgery, Isfahan University of Medical Sciences, Isfahan, Iran.
² Alzahra Research Institute, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran; Network of Immunity in Infection, Malignancy, and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Isfahan, Iran.
³ Alzahra Research Institute, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
⁴ Department of Cardiovascular Medicine, Center for Regenerative Medicine, Mayo Clinic, Rochester, MN, USA.
⁵ Department of Epidemiology and Biostatistics, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran.
⁶ Department of Immunology, Faculty of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
⁷ Functional Neurosurgery Research Center, Shohada Tajrish Comprehensive Neurosurgical Center of Excellence, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
⁸ Alzahra Research Institute, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran; Network of Immunity in Infection, Malignancy, and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), Isfahan, Iran. Electronic address: Hosein.nouri.2018@gmail.com.

Abstract

Background: COVID-19 is speculated to increase the likelihood of relapsing-remitting multiple sclerosis (RRMS) exacerbation.

Objective: To investigate the association between contraction of COVID-19 and incidence of acute MS attacks in RRMS patients six months post-infection.

Methods: This retrospective cohort study compares the risk of relapse in RRMS patients with (n=56) and without COVID-19 (n=69). Incidence of relapse was recorded for six-month following contraction of COVID-19. Incidence of RRMS exacerbation in patients with COVID-19 was compared to patients without COVID-19 (the independent control group) and the same patients six months prior to the COVID-19 pandemic.

Results: A lower incidence rate of RRMS exacerbation was observed in patients that contracted COVID-19 than in patients who did not contract COVID-19 (incidence rate ratio: 0.275; p=0.026). Self-controlled analysis showed no significant difference in relapse rates before the COVID-19 pandemic and after contracting COVID-19 (p=0.222). The relapse risk was not different between patients who had been hospitalized due to COVID-19 severity and those who had not (p=0.710).

Conclusion: COVID-19 contraction may not increase the risk of acute MS attacks shortly following contraction. We hypothesize that COVID-19-associated lymphopenia may partly preclude the autoreactive memory cells from expansion and initiating relapses through a so-called bystander effect of COVID-19 infection.

Keywords: COVID-19; Multiple Sclerosis; Relapsing-Remitting Multiple Sclerosis; SARS-CoV-2.

MeSH terms

Bystander Effect
COVID-19*
Humans
Multiple Sclerosis*
Multiple Sclerosis, Relapsing-Remitting* / epidemiology
Pandemics
Recurrence
Retrospective Studies
SARS-CoV-2