Modifiable Risk Factors of COVID-19 in Patients with Multiple Sclerosis: A Single-Centre Case-Control Study
Federico Montini1, Agostino Nozzolillo4, Paola MV Rancoita5, Chiara Zanetta4, Lucia Moiola4, Federica Esposito4, Federica Cugnata5, Maria Rocca2, Massimo Filippi3, Vittorio Martinelli4
1Neurology Unit, 2Neuroimaging Research Unit, Division of Neuroscience, and Neurology Unit, 3Neuroimaging Research Unit, Division of Neuroscience, Neurology Unit, Neurorehabilitation Unit, and Neurophysiology Service, IRCCS San Raffaele Scientific Institute; Vita-Salute San Raffaele University, 4Neurology Unit, IRCCS San Raffaele Scientific Institute, 5University Centre of Statistics in the Biomedical Sciences (CUSSB), Vita-Salute San Raffaele University
Objective:
To assess risk factors associated with SARS-CoV-2 infection among patients with multiple sclerosis (PwMS).
Background:
Disease- and treatment-associated immune system abnormalities may confer a higher risk of SARS-CoV-2 infection to PwMS.
Design/Methods:
Among patients referring to the MS Center of IRCCS San Raffaele Hospital, we retrospectively collected epidemiological, clinical, and laboratory data of PwMS who got a confirmed COVID-19 infection between March 2020 and March 2021 (MS-COVID, n=149). Afterwards, we pursued a 1:2 matching of a control group by collecting data of PwMS without a history suggestive of previous COVID-19 infection (MS-NCOVID, n=292). MS-COVID and MS-NCOVID patients were matched for age, EDSS, and line of treatment. All participants were not vaccinated against SARS-CoV-2 at the time of the evaluation. We compared neurological examination, premorbid vitamin D levels, anthropometric variables such as BMI, life-style habits (smoke), working-activity, and living environment (number of cohabitants) between the two groups. COVID-19 severity was evaluated in terms of typical symptoms, fever, radiological pneumonia, and hospitalization. Logistic regression and Bayesian network analyses were used to evaluate the association with the development of COVID-19.
Results:
Higher levels of vitamin D (OR=0.94, p<0.001, adjusted p<0.001) and positive smoking status (OR=0.49, p<0.001, adjusted p<0.001) emerged as protective factors against SARS-CoV-2 infection. In contrast, higher number of cohabitants (OR=1.36, p<0.001, adjusted p<0.001) and works requiring direct external contact (OR=2.34, p<0.001, adjusted p=0.004) or in the healthcare sector (OR=3.55, p<0.001, adjusted p=0.004) resulted risk factors for COVID-19 disease. Bayesian network analysis showed that patients working in the healthcare sector, and therefore exposed to increased risk of COVID-19, were usually non-smokers, possibly explaining the protective association between active smoking and COVID-19.
Conclusions:
This case-control study underlines the importance of constant monitoring and supplementation of Vitamin D in PwMS. In the case of pandemic conditions, teleworking may prevent unnecessary risk of infection in these patients.