Does COVID-19 increase the long-term relapsing-remitting multiple sclerosis clinical activity? A cohort study

Masoud Etemadifar,Mehri Salari,Hosein Nouri,Amir Parsa Abhari,Nahad Sedaghat,Shiva Maleki,Alireza Amin

doi:10.1186/s12883-022-02590-9

Abstract

BackgroundSome current evidence is pointing towards an association between COVID-19 and worsening of multiple sclerosis (MS), stressing the importance of preventing COVID-19 among people with MS (pwMS). However, population-based evidence regarding the long-term post-COVID-19 course of relapsing-remitting multiple sclerosis (RRMS) was limited when this study was initiated.ObjectiveTo detect possible changes in MS clinical disease activity after COVID-19.MethodsWe conducted an observational study from July 2020 until July 2021 in the Isfahan MS clinic, comparing the trends of probable disability progression (PDP) – defined as a three-month sustained increase in expanded disability status scale (EDSS) score – and relapses before and after probable/definitive COVID-19 diagnosis in a cohort of people with RRMS (pwRRMS).ResultsNinety pwRRMS were identified with definitive COVID-19, 53 of which were included in the final analysis. The PDP rate was significantly (0.06 vs 0.19, P = 0.04), and the relapse rate was insignificantly (0.21 vs 0.30, P = 0.30) lower post-COVID-19, compared to the pre-COVID-19 period. The results were maintained after offsetting by follow-up period in the matched binary logistic model. Survival analysis did not indicate significant difference in PDP-free (Hazard Ratio [HR] [95% CI]: 0.46 [0.12, 1.73], P = 0.25) and relapse-free (HR [95% CI]: 0.69 [0.31, 1.53], P = 0.36) survivals between the pre- and post-COVID-19 periods. Sensitivity analysis resulted similar measurements, although statistical significance was not achieved.ConclusionWhile subject to replication in future research settings, our results did not confirm any increase in the long-term clinical disease activity measures after COVID-19 contraction among pwRRMS.

Highlights

The pathomechanistic processes involved in multiple sclerosis (MS) are believed to be triggerable by systemic infections, many causing irreversible progression of the disease [1]
While subject to replication in future research settings, our results did not confirm any increase in the long-term clinical disease activity measures after COVID-19 contraction among people with RRMS (pwRRMS)
It should be pointed that a portion of the participants may have been the same as a previously-conducted study contributed by some authors of the present study [14] as the same center was used for identification and enrollment of participants, despite the two studies being conducted separately and independently

Summary

Introduction

The pathomechanistic processes involved in multiple sclerosis (MS) are believed to be triggerable by systemic infections, many causing irreversible progression of the disease [1] This issue gains more importance during a global pandemic. Etemadifar et al BMC Neurology (2022) 22:64 coronavirus disease 2019 (COVID-19) pandemic – could trigger exacerbation of MS by several other mechanisms, e.g., molecular mimicry, bystander activation, and epitope spreading [4] While considering their susceptibility to unfortunate COVID-19 outcomes [5], adopting strategies to prevent COVID-19 in the people with MS (pwMS) gains more importance, if such association could be confirmed by real-world evidence. Population-based evidence regarding the long-term post-COVID-19 course of relapsing-remitting multiple sclerosis (RRMS) was limited when this study was initiated

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Results

Discussion

Conclusion