On the last day of the virtual ECTRIMS meeting, a full session was dedicated to the current developments in MS and COVID19. The updates from case-control studies carried out around the globe on the outcome of MS patients with COVID19 are being followed with great interest. However, it must be said that these are still relatively small numbers, especially when looking at subgroups with different treatments. Of particular interest was the update from the French COVISEP register – where 405 MS patients with COVID19 have been included so far and their clinical outcome assessed using a 7-stage severity scale (from > grade 3 treatment in hospital). The authors were able to show that the risk of severe COVID19 also increases with age and disability level (EDSS) in MS patients. It was also possible to evaluate patient groups with different MS therapies in relation to the clinical course of COVID19 disease. Here, the most unfavorable outcomes were found in the group of untreated MS patients. A multivariate regression analysis was then used to investigate causality relationships. This analysis revealed a higher risk of severe COVID19 in older age, higher EDSS, cardiac pre-existing conditions and obesity – similar risk factors as in the general population. A reduced risk of an unfavorable outcome was found in patients with immunomodulatory therapy with MS basic therapies.
Another important data basis is based on the so-called Global Data Sharing Initiative – a worldwide data collection that many European countries are also participating in. This case-control study now includes 1540 MS patients. These patients were also treated with a wide variety of MS drugs, with disproportionately many patients receiving B-cell depleting therapies (rituximab, ocrelizumab), which could potentially indicate statistical distortion (observational bias). The study investigated the endpoints of hospital admission, admission to an intensive care unit, ventilation and death. As in other studies, reaching these endpoints was associated with older age, the presence of progressive multiple sclerosis and EDSS values of > 6. In relation to the MS therapies, the authors were able to ascertain that, in addition to untreated patients, patients treated with B-cell depleting therapy also had a higher risk of severe COVID 19 disease. Interestingly, patients with B-cell depletion were admitted to hospital and intensive care units more often, but did not die more frequently from COVID19. It should also be considered that due to the approval of B-cell depleting therapies for primary chronic progressive MS, this treatment group is on average older and more affected.
These findings of the global initiative coincide with the observations of the Italian MS register, in which almost 800 MS patients with COVID19 have now been included. Here too, more patients with B-cell depletion had a severe course than would have been expected proportionally. However, it must be kept in mind that these observations are still based on very small case numbers.
Nevertheless, the picture is becoming increasingly clear and ultimately confirms the statements made by MS experts at the beginning of the pandemic. It is not MS or a specific MS therapy that increases the risk of severe COVID19 disease, but primarily older age and comorbidities are the main factors that increase the risk – as in the general population. Therefore, there is no reason to withhold therapy from younger and otherwise healthy MS patients because of the pandemic, or to delay therapy. The choice of medication should be based solely on the activity of MS. In MS patients with older age, higher degree of disability and internal pre-existing conditions, one should, however, reflect more intensively during the pandemic as to whether a cell-depleting immunotherapy is really indicated.
