SARS-CoV-2 serology after COVID-19 in multiple sclerosis: An international cohort study.

Sormani, Maria Pia; Schiavetti, Irene; Landi, Doriana; Carmisciano, Luca; De Rossi, Nicola; Cordioli, Cinzia; Moiola, Lucia; Radaelli, Marta; Immovilli, Paolo; Capobianco, Marco; Brescia Morra, Vincenzo; Trojano, Maria; Tedeschi, Gioacchino; Comi, Giancarlo; Battaglia, Mario Alberto; Patti, Francesco; Fragoso, Yara Dadalti; Sen, Sedat; Siva, Aksel; Furlan, Roberto; Salvetti, Marco

BACKGROUND The MuSC-19 project is an Italian cohort study open to international partners that collects data on multiple sclerosis (MS) patients with COVID-19. During the second wave of the pandemic, serological tests became routinely available. OBJECTIVE To evaluate the seroprevalence of anti-SARS-CoV-2 antibodies according to the use of disease-modifying therapy (DMT) in a subset of patients included in the MuSC-19 data set who had undergone a serological test. METHODS We evaluated the association between positive serological test results and time elapsed since infection onset, age, sex, Expanded Disability Status Scale score, comorbidities and DMT exposure using a multivariable logistic model. RESULTS Data were collected from 423 patients (345 from Italy, 61 from Turkey and 17 from Brazil) with a serological test performed during follow-up. Overall, 325 out of 423 tested patients (76.8%) had a positive serological test. At multivariate analysis, therapy with anti-CD20 was significantly associated with a reduced probability of developing antibodies after COVID-19 (odds ratio (OR) = 0.20, p = 0.002). CONCLUSION Patients with MS maintain the capacity to develop humoral immune response against SARS-COV-2, although to a lesser extent when treated with anti-CD20 drugs. Overall, our results are reassuring with respect to the possibility to achieve sufficient immunization with vaccination.