Susceptibility, severity and immunological factors against SARSCoV- 2 infection in patients with Multiple Sclerosis

Abstract

Given that MS patients are at higher risk of morbimortality due to infection and that this risk is increased in those under immunosuppressant treatments, when the COVID-19 pandemic started it was crucial to study which MS patients where at higher risk of COVID-19 and how DMT influenced in this risk. Additionally, as most MS treatments alter humoral and/or cellular immunity, these immunological responses to SARS-CoV-2 infection and vaccination may be modified by the different treatments. Therefore, the aim of this study is to analyze the incidence, susceptibility and severity risk factors for COVID-19 in MS patients, their humoral and cellular response to SARS-CoV-2 infection and vaccination and the modification in the clinical practice caused by the pandemic. With these objectives in mind, several research proposals were considered. First, we sent an online survey to all our patients to detect those who have had COVID-19, allowing us to estimate an incidence of COVID-19 of 6.3% in our cohort. Additionally, we found that younger patients, with a longer disease duration, living in Barcelona city and who had had contact with an infected person presented a higher risk of COVID-19. In our cohort, age was the only independent factor related to severity. No DMT was related to an increased risk of COVID-19 susceptibility or severity. Next, we evaluated the humoral and cellular immunological response of MS patients who had presented COVID-19. After COVID-19, humoral response decreased in in anti-CD20s-treated patients and increased in male patients, whereas progressive forms decreased cellular response. When SARS-CoV-2 vaccines were available, we performed a humoral and cellular immunological response study after vaccination in collaboration with the Neuroimmunology and MS unit of the Doctor Trueta/Santa Caterina University Hospital of Girona. We detected that humoral response was reduced in SP1RM-treated and anti-CD20s-treated patients. In the later, the humoral response rate increased the longer the interval between last infusion and vaccination. A longer treatment duration also decreased humoral response to vaccines. The cellular response after vaccination was also blunted by SP1RM treatment and in patients over 50 years of age. Finally, we evaluated how the pandemic impacted the clinical practice in our center by analyzing the number of clinical visits, the number of magnetic resonance imaging studies and the number and type of treatment prescriptions during the year 2020 compared to 2019. We found that, during the pandemic, the clinical and radiological activity of our center were maintained but the number of treatment prescriptions was reduced, and the pattern modified. Specifically, there was a change in the high efficacy prescription pattern where anti-CD20s therapy prescription was diminished while natalizumab prescription increased.