BACKGROUND: Patients with Multiple Sclerosis (MS) are prone to severe infections and related mortality due to higher degree of disability and commonly used immunosuppressive disease modifying therapies (DMTs). The high propensity of infection poses a great risk to individuals with MS during the ongoing international pandemic due to the novel coronavirus disease (COVID-19).
PURPOSE: Due to the limited information on the influence of COVID-19 infection in individuals with MS, stemming from low-level study designs such as case studies, the authors of this study conducted a prospective cohort study to assess differing characteristics of individuals with MS who developed mild, moderate and severe cases of the COVID-19 infection.
METHODS:
Subjects/Settings: 40 consecutive MS patients with confirmed COVID-19 via nasopharyngeal/oropharyngeal-PCR from Mar-May 2020 receiving care from 3 different hospital systems in the U.S from Michigan and Illinois were included.
Outcomes collected:
Primary outcome of interest was the clinical severity of COVID-19 determined by the hospital course of an affected individual with MS: Mild course was defined as not requiring hospital admission, Moderate course was defined as requiring admission to general floor only, and Severe course was defined as requiring intensive care unit (ICU) admission and/or death.
Additional information on age, race, sex, smoking status, MS phenotype (Primary Progressive MS, PPMS; Relapsing-Remitting MS, RRMS; Secondary Progressive MS, SPMS), duration of MS, DMT, and comorbidities was collected. Expanded disability status scale (EDSS) from last clinic visit was used for disability assessment with ≥6.0 indicating severe disability.
Statistical analysis: Continuous variables, described by median and Inter-Quartile Range (IQR), were compared using Kruskal-Wallis-H test with post hoc Dunn’s test for pairwise-comparisons. Categorical variables, described by tallies, were compared using Chi-squared test with MonteCarlo simulation and Fisher multiple-pairwise tests post hoc comparisons. Level of significance was set at 0.05.
RESULTS:
| Mild COVID-19 course (no hospital admission) | Moderate COVID-19 course (hospital admission to general floor only) | Severe COVID-19 course (ICU admission and/or death) | P-value | |
| Number of individuals (count) | 19 | 15 | 6 | |
| Age (years, IQR) | 48 [40–51.5] | 57 [50–63] | 66 [58.8–69.5] | 0.0013 |
| Smokers (count) | 0/19 | 5/14 | 1/6 | 0.0145 |
| MS phenotype (count); PPMS=Primary progressive MS, SPMS=Secondary progressive MS | 0/19 [0%] had PPMS and 1/19 [5.26%] had SPMS | 1/14 [7.14%] had PPMS and 5/14 [35.7%] had SPMS | 2/6 [33.3%] had PPMS and 0/6 [0%] had SPMS | 0.0075 |
| Years of MS | 11 (6–14.5) | 16 (11.5–27) | 5 (3−10) | 0.0166 |
| Severe Disability (count); EDSS ≥6.0 | 1/18 | 8/14 | 2/5 | 0.00435 |
| Nursing home resident (count) | 0/19 | 7/15 | 1/6 | 0.0036 |
| DMT use (count) | 17/19 | 12/15 | 3/6 | Not significant |
| Hypertension (count) | 3/19 | 10/15 | 3/6 | 0.0085 |
| Diabetes (count) | 1/19 | 4/15 | 4/6 | 0.005 |
| Days admitted (count, IQR) | NA | 4 (4–9.5) | 15.5 (14.2–16.8) | 0.006 |
| Days with COVID-19 symptoms (count, IQR) | 16 (14–21) | 14 (4–18.5) | 16.5 (14.2–21.8) | Not significant |
| Ventilator use | NA | NA | 4/6 | |
| Death | NA | NA | 4/6 |
Bold indicates significant difference wild mild group at p<0.05 i.e. less than 5% chance of the finding occurring due to error.
Key differences in patient characteristics of MS across the mild, moderate and severe courses of COVID-19:
- Individuals with MS presenting with moderate or severe courses of COVID-19 infection were:
- Older
- Smokers
- Had a progressive phenotype of MS
- Had longer duration of MS
- Had high levels of disability, i.e. needing assistance to walk
- Had high rates of hypertension
- DMT use did not affect the COVID-19 infection course
Key findings related to COVID-19 infection in individuals with MS:
- Overall, initial presenting symptoms and the duration of symptoms were similar among all groups of patients with MS with mild, moderate or severe courses of COVID-19 infection.
- Patients with MS who had moderate and severe courses were more likely to be treated for COVID-19 compared to those with mild courses.
- Patients with severe courses were more likely to be admitted longer compared to those with moderate courses
Study limitations: Small sample size to detect racial and DMT (medication) based differences, especially for the severe course of COVID-19 infection.
CONCLUSIONS:
Individuals with MS who have more severe COVID-19 courses tended to be older, were more likely to suffer from progressive phenotype, and had a higher degree of disability. However, larger studies are warranted to confirm these relationships.
REVIEWED BY: Hina Garg, PT, MS, PhD (Physical therapist, MS PT & Wellness Director)
CITATION
Chaudhry F, Bulka H, Rathnam AS, et al. COVID-19 in multiple sclerosis patients and risk factors for severe infection. Journal of the Neurological Sciences. 2020;418.