SARS-CoV-2 infection and risk of subsequent demyelinating diseases – a nationwide register-based cohort study in Sweden

Tuesday, August 27, 2024

1:45 PM - 2:00 PM CEST

Location: Conv Hall I C

Presenting Author(s)

Fredrik Nyberg, MD PhD

Professor of Register Epidemiology
School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg
M�lndal, Sweden

Slides

Co-Author(s)

SV

Snieguole Vingeliene

Clinical Epidemiology and Biostatistics, School of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro, Sweden, Sweden
Huiqi Li, PhD

Assoc. Prof.
School of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden, Sweden
HB

Helena Backman

Department of Obstetrics and Gynaecology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden, Sweden
RU

Ruzan Udumyan, PhD

Clinical Epidemiology and Biostatistics, Department of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro, Sweden., Sweden
JJ

Johan Jendeberg, MD, PhD

Consultant radiologist
Department of Radiology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
Örebro, Sweden
GR

Gunlög Rasmussen

Department of Infectious Diseases, School of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro, Sweden, Sweden
MS

Martin Sundqvist

Department of Laboratory Medicine, Clinical Microbiology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden, Sweden
KF

Katja Fall

Clinical Epidemiology and Biostatistics, School of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro, Sweden, Sweden
AH

Ayako Hiyoshi, PhD

Clinical Epidemiology and Biostatistics, School of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro, Sweden, Sweden
SM

Scott Montgomery

Clinical Epidemiology and Biostatistics, School of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro, Sweden, Sweden

Background: Viral infections, particularly Epstein-Barr virus (EBV), have been linked with risk of multiple sclerosis (MS). Given the evidence that SARS-CoV-2 infection can have consequences for the central nervous system (CNS) and autoimmune disorders, it might increase risk of MS and other demyelinating diseases of the CNS.

Objectives: We aimed to assess whether SARS-CoV-2 infection is associated with subsequent diagnoses of non-MS demyelinating CNS diseases, MS, and infectious mononucleosis (IM) due to EBV - an important MS risk factor.

Methods: All residents of Sweden aged 3 to 100 years were followed between 1st January 2020 and 30th November 2022, excluding those with demyelinating disease prior to 2020, resulting in 9,981,915 individuals. Exposure was classified as SARS-Cov-2 uninfected or infected, the latter divided by severity, and modelled as a time-varying covariate (uninfected, infection without hospital admission and infected with hospital admission). Cox regression assessed the risk of three separate outcomes: hospital-diagnosed non-MS demyelinating diseases; MS; and IM due to EBV, adjusting for sex, year of birth (age), Charlson comorbidity index, healthcare region and country of birth.

Results: Hospital admission for COVID-19 was associated with raised risk of subsequent non-MS demyelinating disease. Rates per 100 000 person years (and 95% confidence intervals [CI]) were 3.8 (3.6 to 4.1) among those without a COVID-19 diagnosis and 9.0 (5.1 to 15.9) among those admitted to hospital for COVID-19, with an adjusted hazard ratio (aHR) and 95% CI of 2.31 (1.30 to 4.10). Equivalent associations with MS were rates of 9.5 (9.1 to 9.9) and 21.0 (14.5 to 30.5) per 100,000, and an aHR of 2.48 (1.70 to 3.61). For subsequent IM due to EBV, hospital admission for COVID-19 was associated with a rate of 10.5 (6.2 to 17.8) per 100,000 compared with 4.7 (4.4 to 5.0) for those without COVID-19, and an aHR of 5.63 (3.29 to 9.66).

Conclusions: There was increased risk of CNS demyelinating diseases among people admitted to hospital for COVID-19. COVID-19 was also associated with a raised risk of IM due to EBV, an established risk factor for MS. It is possible that at least a proportion of these associations is due to surveillance or referral bias (due to a previous hospital admission for infection), so future research should continue to follow the population that had COVID-19 for development of MS and other demyelinating diseases, which can have long asymptomatic and prodromal phases.