Modifiable Risk Factors of COVID-19 in Patients with Multiple Sclerosis: A Single-Centre Case-Control Study (P2-5.028)

<h3>Objective:</h3> To assess risk factors associated with SARS-CoV-2 infection among patients with multiple sclerosis (PwMS). <h3>Background:</h3> Disease- and treatment-associated immune system abnormalities may confer a higher risk of SARS-CoV-2 infection to PwMS. <h3>Design/Methods:</h3> 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. <h3>Results:</h3> Higher levels of vitamin D (OR=0.94, p&lt;0.001, adjusted p&lt;0.001) and positive smoking status (OR=0.49, p&lt;0.001, adjusted p&lt;0.001) emerged as protective factors against SARS-CoV-2 infection. In contrast, higher number of cohabitants (OR=1.36, p&lt;0.001, adjusted p&lt;0.001) and works requiring direct external contact (OR=2.34, p&lt;0.001, adjusted p=0.004) or in the healthcare sector (OR=3.55, p&lt;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. <h3>Conclusions:</h3> 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. <b>Disclosure:</b> Mr. Montini has nothing to disclose. Dr. Nozzolillo has nothing to disclose. Paola MV Rancoita has nothing to disclose. Chiara Zanetta has nothing to disclose. Dr. Moiola has nothing to disclose. Federica Esposito has received personal compensation in the range of $0-$499 for serving as a Consultant for Merck. Federica Esposito has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novartis. Federica Esposito has received personal compensation in the range of $0-$499 for serving as a Consultant for Novartis. Federica Esposito has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Novartis. Federica Esposito has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Merck. The institution of Federica Esposito has received research support from Italian MS Society. The institution of Federica Esposito has received research support from Italian Ministry of Health. The institution of Federica Esposito has received research support from ERA Net. The institution of Federica Esposito has received research support from European Commission. Federica Esposito has received intellectual property interests from a discovery or technology relating to health care. Dr. Cugnata has nothing to disclose. Maria Assunta Rocca has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Bayer, Biogen, Bristol Myers Squibb, Celgene, Genzyme, Merck Serono, Novartis, Roche, and Teva. The institution of Maria Assunta Rocca has received research support from Italian Ministry of Health, MS Society of Canada and Fondazione Italiana Sclerosi Multipla. Dr. Filippi has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Bayer, Biogen Idec, Merck-Serono, Novartis, Roche, Sanofi Genzyme, Takeda, and Teva Pharmaceutical Industries. Dr. Filippi has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Bayer, Biogen Idec, Merck-Serono, Novartis, Roche, Sanofi Genzyme, Takeda, and Teva Pharmaceutical Industries. Dr. Filippi has received personal compensation in the range of $5,000-$9,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Springer Nature. The institution of Dr. Filippi has received research support from Biogen Idec, Merck-Serono, Novartis, Roche, Teva Pharmaceutical Industries, Italian Ministry of Health, Fondazione Italiana Sclerosi Multipla, and ARiSLA (Fondazione Italiana di Ricerca per la SLA). Dr. Martinelli has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novartis, Biogen, Sanofi Genzyme, TEVA and Merck. Dr. Martinelli has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Merck .