COVID-19 Severity in Multiple Sclerosis: Putting Data Into Context

Neurol Neuroimmunol Neuroinflamm. 2021 Nov 9;9(1):e1105. doi: 10.1212/NXI.0000000000001105. Print 2022 Jan.

Abstract

Background and objectives: It is unclear how multiple sclerosis (MS) affects the severity of COVID-19. The aim of this study is to compare COVID-19-related outcomes collected in an Italian cohort of patients with MS with the outcomes expected in the age- and sex-matched Italian population.

Methods: Hospitalization, intensive care unit (ICU) admission, and death after COVID-19 diagnosis of 1,362 patients with MS were compared with the age- and sex-matched Italian population in a retrospective observational case-cohort study with population-based control. The observed vs the expected events were compared in the whole MS cohort and in different subgroups (higher risk: Expanded Disability Status Scale [EDSS] score > 3 or at least 1 comorbidity, lower risk: EDSS score ≤ 3 and no comorbidities) by the χ2 test, and the risk excess was quantified by risk ratios (RRs).

Results: The risk of severe events was about twice the risk in the age- and sex-matched Italian population: RR = 2.12 for hospitalization (p < 0.001), RR = 2.19 for ICU admission (p < 0.001), and RR = 2.43 for death (p < 0.001). The excess of risk was confined to the higher-risk group (n = 553). In lower-risk patients (n = 809), the rate of events was close to that of the Italian age- and sex-matched population (RR = 1.12 for hospitalization, RR = 1.52 for ICU admission, and RR = 1.19 for death). In the lower-risk group, an increased hospitalization risk was detected in patients on anti-CD20 (RR = 3.03, p = 0.005), whereas a decrease was detected in patients on interferon (0 observed vs 4 expected events, p = 0.04).

Discussion: Overall, the MS cohort had a risk of severe events that is twice the risk than the age- and sex-matched Italian population. This excess of risk is mainly explained by the EDSS score and comorbidities, whereas a residual increase of hospitalization risk was observed in patients on anti-CD20 therapies and a decrease in people on interferon.

MeSH terms

  • Adult
  • COVID-19 / epidemiology*
  • COVID-19 / immunology
  • COVID-19 / physiopathology*
  • COVID-19 / therapy
  • Cohort Studies
  • Comorbidity
  • Female
  • Hospitalization / statistics & numerical data
  • Humans
  • Intensive Care Units / statistics & numerical data
  • Italy / epidemiology
  • Male
  • Middle Aged
  • Multiple Sclerosis / epidemiology*
  • Multiple Sclerosis / immunology
  • Multiple Sclerosis / physiopathology
  • Retrospective Studies
  • Risk Factors
  • Severity of Illness Index