The risk of severe outcomes from COVID-19 infection in patients with multiple sclerosis seems to align with that seen in the general population, new US data suggest.
A separate study from the UK also found similar trends of rates of COVID-19 infection in patients with MS and the general population.
Both studies were presented September 26 at a special session on multiple sclerosis and COVID-19 at a final “Encore” event as part of the 8th Joint European Committee for Treatment and Research in Multiple Sclerosis-Americas Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS-ACTRIMS) 2020, this year known as MSVirtual2020.
The US data appear consistent with studies from several other countries, in that worse COVID-19 outcomes increase with age and higher disability levels, both of which would be expected from findings in the general population.
The US data also show a clear effect of race in MS, with higher rates of adverse COVID-19 outcomes in Black patients, again in line with what is seen in the general population.
“I would say the results from our study and in general do not suggest that MS itself is associated with higher risks of severe COVID-19 outcomes compared with the general population,” Amber Salter, PhD, told Medscape Medical News.
Salter, who is assistant professor of biostatistics at Washington University School of Medicine, St. Louis, Missouri, presented data from the COViMS North American registry, set up for healthcare providers to report persons with MS who are infected with COVID-19.
The COViMS registry so far has information on 858 patients with MS who have COVID-19 (80% verified by a positive test), as reported from 150 different healthcare providers in the United States and Canada.
The average age was 48 years, with average disease duration of 13.6 years. MS clinical course was reported as relapsing remitting in 78%, secondary progressive in 15%, and primary progressive in 5%. Most patients (72%) were fully ambulatory, 16% could walk with assistance, and 12% were nonambulatory.
Severe COVID-19 outcomes were classified as mortality (which occurred in 5.7% of the cohort), mortality/ICU admission (13.6%) and mortality/ICU admission/hospitalization (30.2%).
Results were adjusted for many different covariates, including sex, age, smoking, MS clinical course (relapsing, progressive), disease duration, ambulation, individual comorbidities (cardiovascular disease, cerebrovascular disease, chronic kidney disease, chronic lung disease, diabetes, hypertension, morbid obesity), and disease-modifying therapy use.
In multivariable logistic regression analyses, older age, having chronic renal disease, and being nonambulatory were consistently associated with increased odds of poorer outcomes.
Chronic kidney disease had the strongest association with mortality (odds ratio [OR] 28.6; P < .001). Other factors associated with mortality included cardiovascular disease (OR, 4.35; P = .009); age (OR per 10 years, 1.91; P = .012), and male sex (OR, 2.60; P = .041).
Patients who were nonambulatory had a higher risk of mortality/ICU admission/hospitalization (OR, 3.32; P = .003). This endpoint was also increased in patients on anti-CD20 drugs compared with other disease-modifying treatment (OR, 2.31; P = .002), consistent with results from at least two other studies.
Disease-modifying therapy in general was not associated with an increased risk of worse outcomes.
“There was some concern at the outset about the effect of disease-modifying therapies on COVID-19 outcomes, but most studies have not found an increased risk of worse outcomes in patients on such drug treatments, with the possible exception of anti-CD20 drugs,” Salter told Medscape Medical News.
“Some disease-modifying therapies may actually be protective (particularly interferon) and studies are investigating whether they may have a role in the treatment of COVID-19,” she added.
“The factors in MS patients that we and others have found to be associated with worse COVID-19 outcomes may not be specific to MS. Older age is known to be a primary risk factor for worse COVID-19 outcomes in the general population, and increasing disability presumably tracks with worse general heath,” Salter commented.
“I would say the overall data are fairly reassuring for MS patents,” she concluded.
Black Patients Have Higher Risk
One worrying finding in the North American data, however, was the effect of race.
“We found an independent effect of race for worse COVID-19 outcomes in MS patients,” Slater said.
Of the 858 patients in the COViMS registry, 65.7% were White and 26.1% were Black. Black individuals were more likely to be younger, never smokers, have shorter MS duration, a relapsing MS course, and have comorbidities compared with White patients. A higher proportion of black patients had hypertension (40.2% vs 19.5%) and morbid obesity (17% vs 9.5%).
Results showed that mortality rates were not statistically different between White and Black patients, but Black race was associated with increased risk of mortality and/or ICU admission compared with White patients (16.9% vs 12.8%), and multivariate logistic regression analysis showed black race was independently associated with mortality/ICU admission after adjustments for covariates (OR, 3.7; P = .002).
Black race was also associated with increased risk of mortality/ICU admission/hospital admission (35.8% vs 30.2%), and after adjustment for covariates this was found to be an independent predictor (OR, 1.7; P = .04).
“This higher COVID-19 risk in black individuals is also seen in the general population, so these results are not that surprising and it doesn’t appear to be an effect specific to MS patients,” Salter commented to Medscape Medical News.
UK Data on Risk of Contracting COVID-19
A UK study has also suggested race to be an independent predictor in the risk of contracting COVID-19 in patients with MS.
The study of more than 5000 patients with MS showed that those from a Black, Asian and Minority Ethnic (BAME) group were twice as likely to report having COVID-19 than those who were white.
The study, which was conducted during the UK lockdown, also found that the trend of COVID-19 infection in patients with MS is comparable to that of the UK general population.
Presenting the data, Afagh Garjani, MD, concluded: “During a period with strict physical distancing measures, patients with MS are not at an increased risk of contracting COVID-19.”
Garjani, a neurology clinical research fellow at the University of Nottingham, UK, explained that the COVID-19 pandemic has introduced uncertainties into the MS community, and the focus so far has been the severity of infection among people with MS who have COVID-19.
“This approach has left questions about the risk of contracting disease in people with MS unanswered, which has implications as society gradually returns to normal,” she said.
Garjani presented data from the United Kingdom MS Register (UKMSR), which has been collecting demographic and MS-related data since 2011 from patients with MS throughout the UK.
On March 17 — just before the lockdown in UK — existing participants of the UKMSR were asked to join the COVID-19 study. The study was also advertised through social media. In this ongoing study, people with MS answered a COVID-19-related survey at participation and a different follow-up survey every 2 weeks depending on whether they contracted COVID-19.
The COVID-19 study included 5309 patients with MS. The mean age of the study population was 52.4 years, 76.1% were female, and 95.7% were White. Of the 5309 patients, 535 (10%) reported a self-diagnosis of COVID-19. Because of limited availability of tests in the UK at the time, only 75 patents had a positive PCR result.
“To our knowledge, this is the largest community-based study of COVID-19 in patients with MS worldwide,” Garjani said.
She presented results from the period March 23 to June 24, when the UK was in a period of lockdown with vulnerable groups encouraged to self-isolate completely.
In this MS cohort, 47% reported self-isolating at some point. Those at older age and higher Expanded Disability Status Scale (EDSS) score were more likely to have self-isolated.
The researchers did not find that patients with progressive MS or those on disease-modifying therapies in general isolated more, but patients on monoclonal antibody drugs and fingolimod (Gilenya) were more likely to self-isolate vs those on other therapies. “This may be because there are concerns about infection with these drugs and patients on these therapies may be more concerned about contracting COVID-19,” Garjani suggested.
In terms of contracting COVID, the researchers found a reduced risk of COVID-19 (self-diagnosed) in patients with older age and higher EDSS. “This is not really surprising that these patients were more likely to self-isolate,” Garjani commented.
No association was seen between type of MS, disease duration, disease-modifying therapy in general and risk of COVID-19. No individual drug treatment increased risk vs no therapy or vs self-injectables.
But there was an increased risk of contracting the virus in patients whose race was Black, Asian, or Minority Ethnic (OR, 2.2), which is in line with findings from the general population.
“This study is unique — the denominator is all people with MS. We are looking primarily at the risk of contracting COVID-19. Other studies are focusing more on people with MS who have COVID and assessing risk of a severe COVID outcome. Our results are not contradicting the findings from those studies,” Garjani told Medscape Medical News.
The results were similar only when patients with a confirmed COVID-19 test were considered.
In terms of outcomes in those who reported COVID-19 infection, preliminary results have not shown any MS factors — such as EDSS, age, type of MS, drug therapy in general — to be associated with outcome.
“Since the COVID-19 outbreak started there has been concern among MS patients, especially among those on disease-modifying therapies, about whether they are at increased risk of infection and severe disease,” Garjani said.
“We found similar trends of rates of infection in MS patients and the general population, and no signal of increased risks in those with higher EDSS or progressive MS. The caveat is that this study was conducted in a period of lockdown, but we adjusted for self-isolating behavior in the multivariable regression analysis,” she noted.
Salter is a statistical editor for the AHA journal Circulation: Cardiovascular Imaging. Garjani has disclosed no relevant financial relationships.
8th Joint European Committee for Treatment and Research in Multiple Sclerosis-Americas Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS-ACTRIMS) 2020: Session SS02. Presented September 26, 2020.