Clinical characteristics of African Americans vs Caucasian Americans with multiple sclerosis

Prevalence and disease disability in immigrants with multiple sclerosis in Malmö, southern Sweden

BACKGROUND

Multiple sclerosis (MS) is the most common chronic demyelinating disease of the central nervous system and the major non-traumatic cause of permanent disability in young adults. Several migration studies have been performed over the years suggesting a pattern of higher disease disability in certain ethnic groups. To our knowledge, differences in disease progression in immigrants have not been studied in Sweden before. Thus, the aims of our study were to estimate the prevalence of multiple sclerosis among first-generation immigrants in the City of Malmö and to compare differences in disease severity with the native population.

METHODS

All persons with multiple sclerosis living in Malmö on prevalence day 31 Dec 2010 were included. Cases were classified according to the country of birth into Scandinavians, Western and non-Western.

RESULTS

The crude prevalence was 100/100,000 (95% CI, 80-124) among first-generation immigrants, 154/100,000 (95% CI, 137-173) among individuals with Scandinavian background, 123/100,000 (95% CI, 94-162) in the Western group and 76/100,000 (95% CI, 53-108) in the non-Western group. The mean Multiple Sclerosis Severity Score (MSSS) value among Scandinavians was 4.2 (SD 3.5), whereas the figures in the immigrant group were 4.6 (SD 3.3) and 5.2 (SD 3.7) among Westerns respectively non-Westerns, which differences were not statistically significant. When adjusting for gender, age at onset and initial disease course, the mean MSSS difference between the non-Western and the Scandinavian individuals was 1.7 (95% CI 0.18-3.3, p = 0.030). There were no differences on time to diagnosis or the time from diagnosis to treatment initiation between the three groups.

CONCLUSIONS

We found a lower prevalence among Western and non-Western first-generation immigrants compared to the Scandinavian population and a more severe disease in non-Western immigrants than in Scandinavians.

A national registry-based study of ethnic differences in people with multiple sclerosis in Iran

OBJECTIVE

The relationship between MS and ethnicity has been understudied in the Middle East compared to the United States and Europe. As Iran as the highest prevalence of MS in the Middle East, we decided to investigate the demographic and clinical differences in people with MS (pwMS) from major ethnicities Iran.

METHODS

In a cross-sectional study using data from National Multiple Sclerosis Registry in Iran. PwMS from six provinces were chosen and interviewed for determining their ethnicity. Persians (Fars), Kurds, Lurs, Azeris and Arabs with a clear ethnic background were included. Recorded data from the registry was used to compare the demographic and clinical features.

RESULTS

A total of 4015 pwMS (74.2% female) were included in the study with an average age of 36.76 ± 9.68 years. Persians and Kurds had the highest percentage of pwMS in youngest and oldest age groups, respectively, with 2.9% and 5.7% (p<0.01). The highest average age of onset was seen in Persians (29.47 ± 8.89) and the lowest observed in Mazandaranis (26.82 ± 7.68, p<0.01). Azeris and Kurds had the highest proportions of pwMS diagnosed <18 and >55, at rates of 12% and 1.6%, respectively (p<0.01). There were statistically significant differences in distribution of phenotypes (p<0.01) and time to progression to secondary progressive MS (p<0.01) such that Persians had the highest rate of clinically isolated syndrome (CIS) at 19.3% and Arabs had highest rates of relapsing-remitting MS (86.2%) and secondary progressive MS (16.4%). Lurs, Azeris and Mazandaranis had significantly more patients progressing to secondary-progressive MS <5 years from diagnosis (p<0.01). There was a significant difference in number of relapses between the ethnicities (p<0.01) with Lurs having the highest proportion of participants reporting >4 relapses with 23.0% and Azeris having the highest percentage of pwMS reporting no relapse (53.0%). Kurds had the highest Expanded Disability Status Scale (EDSS) average at 2.93 ± 1.99 and Lurs had the lowest with 1.28 ± 1.25 (p<0.01). The differences in prevalence of positive family history for the whole cohort between ethnicities were significant (P=0.02), ranging from 12.8% in Kurds to 19.6% in Persians.

CONCLUSION

We found Persians to have higher rates of pediatric MS and higher rates of CIS. Kurds and Lurs had higher and lower EDSS scores, respectively. Lurs and Persian had higher annual relapse rates. We also found lower rates of SPMS among Arabs and earlier progression to SPMS in Lurs, Azeris and Mazandaranis. Such differences highlight the importance of the potential role of ethnicities in diagnosis and prognosis of MS, especially considering their observation within the geographical limits of a single country.

Clinical trials for progressive multiple sclerosis: progress, new lessons learned, and remaining challenges

Despite the success of disease-modifying treatments in relapsing multiple sclerosis, for many individuals living with multiple sclerosis, progressive disability continues to accrue. How to interrupt the complex pathological processes underlying progression remains a daunting and ongoing challenge. Since 2014, several immunomodulatory approaches that have modest but clinically meaningful effects have been approved for the management of progressive multiple sclerosis, primarily for people who have active inflammatory disease. The approval of these drugs required large phase 3 trials that were sufficiently powered to detect meaningful effects on disability. New classes of drug, such as Bruton tyrosine-kinase inhibitors, are coming to the end of their trial stages, several candidate neuroprotective compounds have been successful in phase 2 trials, and innovative approaches to remyelination are now also being explored in clinical trials. Work continues to define intermediate outcomes that can provide results in phase 2 trials more quickly than disability measures, and more efficient trial designs, such as multi-arm multi-stage and futility approaches, are increasingly being used. Collaborations between patient organisations, pharmaceutical companies, and academic researchers will be crucial to ensure that future trials maintain this momentum and generate results that are relevant for people living with progressive multiple sclerosis.

Walking and physical performance in black and white adults with multiple sclerosis controlling for social determinants of health

BACKGROUND

There is evidence for reduced walking and physical performance in persons with multiple sclerosis (MS) compared with healthy controls (HCs). There is further evidence suggesting increased overall mobility disability in Black persons with MS compared with White counterparts, yet little is known about the interplay of social determinants of health (SDOH) when considering differences in walking and physical performance.

PURPOSE

This cross-sectional, comparative study examined differences in walking and physical performance in Black and White persons with MS and HCs (MS Status), statistically controlling for SDOH.

METHODS

The study sample consisted of 208 persons with MS (141 White participants and 67 Black participants) and 95 HCs (59 White participants and 36 Black participants). Walking and physical function were measured using timed 25-foot walk (T25FW), six-minute walk (6MW), timed-up-and-go (TUG), and short physical performance battery (SPPB). We examined the differences in the walking and physical functions as a function of MS Status (MS vs. HCs) and Race (Black vs. White) using Multivariate Analysis of Covariance, controlling for age, sex, marital status and SDOH (i.e., education, employment, income).

RESULTS

There were no significant interactions between MS Status and Race on the outcomes, and the main effects of MS Status and Race remained statistically significant, controlling for SDOH and covariates. The main effects indicated significant lower T25FW (F = 34.6, p < .001, Ƞp2 = 0.11), 6MW (F = 58.5, p < .001, Ƞp2 = 0.18), TUG (F = 22.1, p < .001, Ƞp2 = 0.08), and SPPB (F = 25.2, p < .001, Ƞp2 = 0.09) performance for MS than HCs, and lower T25FW (F = 15.5, p < .001, Ƞp2 = 0.05), 6MW (F = 11.6, p < .001, Ƞp2 = 0.04), and TUG (F = 4.1, p < .05, Ƞp2 = 0.02) performance in Black than White samples.

CONCLUSIONS

We conclude that MS Status and Race independently influence walking and physical performance even after accounting for SDOH, and Black persons with MS have compromised walking and physical performance, perhaps necessitating focal rehabilitation.

Podcast on Identifying and Understanding Barriers to Care in Underserved Populations With MS in the United States

Multiple sclerosis (MS) can affect people from all racial and ethnic backgrounds, but, historically, the incidence of MS in the United States was thought to be highest in White individuals. More recent data suggest that the incidence of MS in Black or African American individuals is comparable to that in White individuals. In Hispanic or Latino individuals, incidence of MS is lower, but age of onset may be earlier compared with White individuals. Additionally, there are important differences in MS disease severity, disease progression, and mortality in Black or African American and Hispanic or Latino populations. Compared with their White counterparts, individuals from these underrepresented groups are more likely to be affected by MS in specific areas of the nervous system, such as accelerated loss of retinal and brain tissue in Black or African American individuals and optic neuritis in Hispanic individuals. Additionally, Black or African American individuals with MS tend to have an aggressive disease course, earlier disability, and higher risk of requiring ambulatory assistance. Although these differences may be attributed to genetic factors, systemic racism and biases and barriers to accessing care may perpetuate health disparities. Moreover, non-White communities remain broadly underrepresented in clinical trials; however, it is vital that these populations are appropriately represented so that any potential differences in drug efficacy or safety implications are detected. Thus, it is important to increase awareness of MS in these populations. In this podcast, the authors discuss characteristics of MS in Black or African American and Hispanic or Latino populations, identify barriers to care, and propose solutions to improve access to MS care in these populations. MP4 (358385 KB).

A retrospective analysis of the ethnicity of individuals referred to a tertiary neuropsychology service in the United Kingdom

Objective: Ethnic minorities comprise approximately 18% of the UK population and are at high risk of developing neurological conditions. Despite this, there is little information regarding their access to neuropsychology services. This study evaluated whether ethnic minorities were proportionally represented in a tertiary neuropsychology department in the UK in accordance with census data for the region. We also aimed to highlight which ethnic groups were over- and underrepresented. Method: Anonymised demographic data of 3429 outpatient and 3304 inpatient referrals to an adult UK neuropsychology department was collected. These data were compared to the 2021 UK census data for the region. Results: Ethnicities in both the outpatient referrals (χ2(15) = 24066.55, p < .001) and inpatient referrals (χ2(15) = 35940924.75, p < .001) are significantly different from the Census. All ethnic minorities were underrepresented in adult neuropsychology referral data for both outpatient settings (-0.06% to -4.66%) and inpatient settings (-0.01% to -4.99%). Pakistani individuals were the most underrepresented across all settings, followed by individuals from an African background. Conversely, individuals of White British ethnicity were overrepresented in both outpatient settings (+10.73%) and inpatient settings (+15.68%). Conclusions: The UK ethnic minorities were not referred to a neuropsychology service relative to regional population prevalence. This contradicts their increased susceptibility for risk of neurological conditions but may also indicate the inaccessibility of neuroscience services for ethnic minorities. Replicating this study across different regions and gathering data on prevalence rates for different neurological conditions across ethnicity is recommended. Additionally, improving accessibility of neuropsychology services for British ethnic minorities should be prioritised.

Multiple Sclerosis in Black and Hispanic Populations: Serving the Underserved

Multiple sclerosis has historically been characterized as a disease that affects young women of European ancestry, but recent studies indicate that the incidence and prevalence of the disease is much higher in Black and Hispanic populations than previously recognized. There is evidence that there is a more severe disease course in these populations. , but the intersection of genetic underpinnings and social determinants of health (SDOH) is poorly understood due to the lack of diversity in clinical research. Improving health disparities will involve multiple stakeholders in efforts to improve SDOH and raise awareness about research involvement and the importance of developing personalized health care plans to combat this disease.

Leveraging Real-World Evidence and Observational Studies in Treating Multiple Sclerosis

Randomized controlled trials (RCTs) are essential for regulatory approval of disease-modifying therapies (DMTs), yet their strict selection criteria often lead to limited generalizability. Observational studies using real-world data (RWD) allow for more inclusive heterogeneous cohorts resulting in higher external validity to inform treatment practices. As reviewed in this article, well-designed comparative effectiveness studies are an important application of RWD. Although, like RCTs, observational studies have their own set of limitations, including various biases that may confound results, advanced statistical methods can mitigate many of these limitations. A focus on personalized treatment will continue to add value to individualize MS care.

Modifiable risk factors for multiple sclerosis have consistent directions of effect across diverse ethnic backgrounds: a nested case-control study in an English population-based cohort

BACKGROUND

Multiple sclerosis is a leading cause of non-traumatic neurological disability among young adults worldwide. Prior studies have identified modifiable risk factors for multiple sclerosis in cohorts of White ethnicity, such as infectious mononucleosis, smoking, and obesity during adolescence/early adulthood. It is unknown whether modifiable exposures for multiple sclerosis have a consistent impact on risk across ethnic groups.

AIM

To determine whether modifiable risk factors for multiple sclerosis have similar effects across diverse ethnic backgrounds.

METHODS

We conducted a nested case-control study using data from the UK Clinical Practice Research Datalink. Multiple sclerosis cases diagnosed from 2001 until 2022 were identified from electronic healthcare records and matched to unaffected controls based on year of birth. We used stratified logistic regression models and formal statistical interaction tests to determine whether the effect of modifiable risk factors for multiple sclerosis differed by ethnicity.

RESULTS

We included 9662 multiple sclerosis cases and 118,914 age-matched controls. The cohort was ethnically diverse (MS: 277 South Asian [2.9%], 251 Black [2.6%]; Controls: 5043 South Asian [5.7%], 4019 Black [4.5%]). The age at MS diagnosis was earlier in the Black (40.5 [SD 10.9]) and Asian (37.2 [SD 10.0]) groups compared with White cohort (46.1 [SD 12.2]). There was a female predominance in all ethnic groups; however, the relative proportion of males was higher in the South Asian population (proportion of women 60.3% vs 71% [White] and 75.7% [Black]). Established modifiable risk factors for multiple sclerosis-smoking, obesity, infectious mononucleosis, low vitamin D, and head injury-were consistently associated with multiple sclerosis in the Black and South Asian cohorts. The magnitude and direction of these effects were broadly similar across all ethnic groups examined. There was no evidence of statistical interaction between ethnicity and any tested exposure, and no evidence to suggest that differences in area-level deprivation modifies these risk factor-disease associations. These findings were robust to a range of sensitivity analyses.

CONCLUSIONS AND RELEVANCE

Established modifiable risk factors for multiple sclerosis are applicable across diverse ethnic backgrounds. Efforts to reduce the population incidence of multiple sclerosis by tackling these risk factors need to be inclusive of people from diverse ethnicities.

Clinical and radiologic differences between early onset, late onset, and very late onset adult multiple sclerosis

BACKGROUND

Previous studies suggested possible differences in clinical and radiologic characteristics between early-onset multiple sclerosis (EOMS) and late-onset MS (LOMS). However, differences between LOMS and very late onset MS (VLOMS) are largely unknown.

METHODS

We performed a retrospective review of medical records of patients diagnosed with MS between 8/1/2017 and 3/1/2022 at the comprehensive MS center of the Froedtert and Medical College of Wisconsin. We included adult patients with MS diagnosis who were 60 years or older - VLOMS, 50-59 years old at diagnosis - LOMS, or were 18-30 years old at diagnosis - EOMS and had complete imaging and clinical records. Clinical presentation and location of demyelinating lesions at the onset of diagnosis were extracted and compared using the chi-square test, p<0.05.

RESULTS

A total of 246 newly diagnosed patients were identified. Of which 54 were EOMS, 29 were LOMS, and 35 were VLOMS. The sex ratio was not different between groups. EOMS had a higher percentage of patients who self-identified as black, while LOMS had a higher percentage of patients who self-identified as white. LOMS and VLOMS showed significant differences in the presence of tremors and lesion distribution at the onset. Older onset patients were more likely to present with motor symptoms, sphincter dysfunction, fatigue, and tremor. EOMS was more likely to present with cerebellum and occipital lobe lesions, and lesions were more likely to show contrast enhancement on MRI at diagnosis.

CONCLUSION

Our findings revealed novel clinical and imaging characteristics differences between VLOMS and LOMS. The current classification of LOMS may benefit from revision to better align with chronological age classification for old age >60 instead of the current standard in the literature of >50 years.

Influence of Admixture on Phenotypes

Individuals of European descent have historically been the focus of genetic studies and possess relatively homogenous genomes. As a result, analytical methods have been developed and optimized with such genomes in mind. African-descent and Latino individuals generally possess genomes of greater architectural complexity due to mosaic genomic ancestry, which can extensively and intricately impact phenotypic expression. As such, genetic analyses of admixed individuals require that genetic admixture be quantified to accurately model the impact of genetic variation on phenotypic expression. In this overview, we explore how fundamental genetic concepts such as linkage disequilibrium and differential allele frequency interact with genetic admixture to uniquely influence phenotypes in admixed individuals. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC.

Stress indicators in minorities with multiple sclerosis

Black Americans with multiple sclerosis (MS) experience higher levels of disease-related disability compared to White Americans (Marrie et al., 2006). Comorbidities such as depression and anxiety, which are underdiagnosed and undertreated in this population, negatively impact quality of life and treatment outcomes for people living with multiple sclerosis (plwMS) (D'Alisa et al., 2006; Marrie et al., 2009; Stepleman et al., 2014). Acts of discrimination toward Black Americans is associated with stress, which is a contributing factor for depression (Carter, 2017; Nadimpalli, 2015; Williams and Mohammed, 2009). This study compared the severity of multiple sclerosis symptoms amongst Black Americans and White Americans, and whether worsened MS symptoms in Black Americans are associated with increased experiences of discrimination. Data was analyzed from 143 plwMS in the Stress Indicators in Minorities with Multiple Sclerosis (SiMMS) study. Using the Mann-Whitney U test, significant differences were found on the NIH Emotional Distress - Anxiety measure (U = 1466.500, p = 0.045) and NIH Sleep Disturbance measure (U = 1467.000, p = 0.044) between the Black participant and the White participant groups. Discrimination was significantly correlated with both NIH Emotional Distress - Anxiety (r = 0.677, p < .001) and NIH Sleep Disturbance (r = 0.446, p = .007) in Black MS individuals. Additionally, several physiological condition and psychological outcome measures were correlated with the NIH Emotional Distress - Anxiety and NIH Sleep Disturbance measures. This study contributes to literature highlighting the negative impacts of discrimination and race related stress on the physical and mental health of Black Americans.

Real-World Safety and Effectiveness After 5 Years of Dimethyl Fumarate Treatment in Black and Hispanic Patients with Multiple Sclerosis in ESTEEM

INTRODUCTION

Multiple sclerosis (MS) clinical trials have included low numbers of patients from racial and ethnic minority populations; therefore, it is uncertain whether differences exist in response to disease-modifying therapies. We evaluated the real-world safety and effectiveness of dimethyl fumarate (DMF) treatment over 5 years in four patient cohorts: Black, non-Black, Hispanic, and non-Hispanic people with relapsing-remitting MS.

METHODS

ESTEEM is an ongoing, 5-year, multinational, prospective study evaluating the long-term safety and effectiveness of DMF in people with MS. The analysis included patients newly prescribed DMF in routine practice at 393 sites globally.

RESULTS

Overall, 5251 patients were analyzed (220 Black, 5031 non-Black; 105 Hispanic, 5146 non-Hispanic). Median (min-max) months of follow-up was 32 (0-72) for Black, 29 (1-77) for Hispanic, and 41 (0-85) for both the non-Black and non-Hispanic populations. In total, 39 (18%) Black and 29 (28%) Hispanic patients reported adverse events leading to treatment discontinuation versus 1126 (22%) non-Black and 1136 (22%) non-Hispanic patients; gastrointestinal disorders were the most common in all subgroups. Median lymphocyte counts decreased by 37% in Black, 40% in non-Black, 10% in Hispanic, and 39% in non-Hispanic patients in the first year, then remained stable and above the lower limit of normal in most patients. Annualized relapse rates (ARRs) (95% confidence intervals) up to 5 years were 0.054 (0.038-0.078) for Black, 0.077 (0.072-0.081) for non-Black, 0.069 (0.043-0.112) for Hispanic, and 0.076 (0.072-0.081) for non-Hispanic populations, representing reductions of 91-92% compared with ARR 12 months before study entry (all p < 0.0001).

CONCLUSION

The safety profile of DMF in these subgroups was consistent with the overall ESTEEM population. Relapse rates remained low in Black and Hispanic patients, and consistent with non-Black and non-Hispanic patients. These data demonstrate a comparable real-world treatment benefit of DMF in Black and Hispanic patients.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02047097.

Social determinants of health and disparate disability accumulation in a cohort of Black, Hispanic, and White patients with multiple sclerosis

BACKGROUND

Black and Hispanic patients with multiple sclerosis (MS) have been shown to accumulate greater multiple sclerosis-associated disability (MSAD) than White patients. Disparities in social determinants of health (SDOH) among these groups have also been reported.

OBJECTIVE

To determine the extent to which associations of race and ethnicity with MSAD may be attributable to differences in SDOH.

METHODS

Retrospective chart analysis of patients at an academic MS center grouped by self-identified Black (n = 95), Hispanic (n = 93), and White (n = 98) race/ethnicity. Individual patient addresses were geocoded and matched with neighborhood-level area deprivation index (ADI) and social vulnerability index (SVI).

RESULTS

Average Expanded Disability Status Scale (EDSS) scores at last-recorded evaluations of White patients (1.7 ± 2.0) were significantly lower than Black (2.8 ± 2.4, p = 0.001) and Hispanic (2.6 ± 2.6, p = 0.020) patients. Neither Black race nor Hispanic ethnicity was significantly associated with EDSS in multivariable linear regression models that included individual-level SDOH indicators and either ADI or SVI.

CONCLUSION

Black race and Hispanic ethnicity are not significantly associated with EDSS in models that include individual and neighborhood-level SDOH indicators. Further research should elucidate mechanisms by which structural inequities affect MS disease course.

Diversity, Equity, and Inclusion in the Multiple Sclerosis Community: A Call to Action

Many medical organizations have begun to confront the longstanding problem of inequalities in health care delivery and the undeniable effect of disparities on health outcomes. The Consortium of Multiple Sclerosis Centers (CMSC) recognizes that disparities affect the lives of many people with multiple sclerosis (MS) and acknowledges the need to address this as an organization. The CMSC recently (1) appointed a task force, (2) conducted a survey of its membership, (3) commissioned this review article and call to action, and (4) formulated a mission statement on diversity, equity, and inclusion (DEI), which was adopted by the CMSC's Board of Governors in March 2023. This paper summarizes recent literature on health care disparities in MS, particularly those relating to race/ethnicity, sexual orientation, and gender identity. It presents findings from CMSC's survey of members' awareness of DEI issues, the need for education and resources for MS care providers, and existing institutional policies on DEI in the members' practice settings. It also presents the task force's recommendations for next steps, which includes the goal of greater diversity in the MS workforce of the future. The CMSC will continue to revisit DEI policies and practices over time with the goal of motivating greater awareness, momentum, and positive changes within the MS community.

Characteristics of multiple sclerosis and demyelinating disease in an Asian American population

BACKGROUND

Race and ancestry influence the course of multiple sclerosis (MS).

OBJECTIVES

Explore clinical characteristics of MS and neuromyelitis optica spectrum disorder (NMOSD) in Asian American patients.

METHODS

Chart review was performed for 282 adults with demyelinating disease who self-identified as Asian at a single North American MS center. Demographics and clinical characteristics were compared to non-Asian MS patients and by region of Asian ancestry.

RESULTS

Region of ancestry was known for 181 patients. Most (94.7%) preferred English, but fewer East Asian patients did (80%, p = 0.0001). South Asian patients had higher neighborhood household income (p = 0.002). Diagnoses included MS (76.2%) and NMOSD (13.8%). More patients with NMOSD than MS were East and Southeast Asian (p = 0.004). For MS patients, optic nerve and spinal cord involvement were similar across regions of ancestry. Asian MS patients were younger at symptom onset and diagnosis than non-Asian MS patients. MS Severity Scale scores were similar to non-Asian MS patients but worse among Southeast Asians (p = 0.006).

CONCLUSIONS

MS severity was similar between Asian American patients and non-Asian patients. Region of ancestry was associated with differences in sociodemographics and MS severity. Further research is needed to uncover genetic, socioeconomic, or environmental factors causing these differences.

Neuron-binding antibody responses are associated with Black ethnicity in multiple sclerosis during natalizumab treatment

Multiple sclerosis is an inflammatory degenerative condition of the central nervous system that may result in debilitating disability. Several studies over the past twenty years suggest that multiple sclerosis manifests with a rapid, more disabling disease course among individuals identifying with Black or Latin American ethnicity relative to those of White ethnicity. However, very little is known about immunologic underpinnings that may contribute to this ethnicity-associated discordant clinical severity. Given the importance of B cells to multiple sclerosis pathophysiology, and prior work showing increased antibody levels in the cerebrospinal fluid of Black-identifying, compared to White-identifying multiple sclerosis patients, we conducted a cohort study to determine B cell subset dynamics according to both self-reported ethnicity and genetic ancestry over time. Further, we determined relationships between ethnicity, ancestry, and neuron-binding IgG levels. We found significant associations between Black ethnicity and elevated frequencies of class-switched B cell subsets, including memory B cells; double negative two B cells; and antibody-secreting cells. The frequencies of these subsets positively correlated with West African genetic ancestry. We also observed significant associations between Black ethnicity and increased IgG binding to neurons. Our data suggests significantly heightened T cell-dependent B cell responses exhibiting increased titres of neuron-binding antibodies among individuals with multiple sclerosis identifying with the Black African diaspora. Factors driving this immunobiology may promote the greater demyelination, central nervous system atrophy and disability more often experienced by Black-, and Latin American-identifying individuals with multiple sclerosis.

Higher frequency of Human herpesvirus-6 (HHV-6) viral DNA simultaneously with low frequency of Epstein-Barr virus (EBV) viral DNA in a cohort of multiple sclerosis patients from Rio de Janeiro, Brazil

Multiple sclerosis (MS) is a chronic neuroinflammatory and neurodegenerative disease of the central nervous system (CNS). The etiology of MS is not well understood, but it's likely one of the genetic and environmental factors. Approximately 85% of patients have relapsing-remitting MS (RRMS), while 10-15% have primary progressive MS (PPMS). Epstein-Barr virus (EBV) and Human herpesvirus 6 (HHV-6), members of the human Herpesviridae family, are strong candidates for representing the macroenvironmental factors associated with MS) pathogenesis. Antigenic mimicry of EBV involving B-cells has been implicate in MS risk factors and concomitance of EBV and HHV-6 latent infection has been associated to inflammatory MS cascade. To verify the possible role of EBV and HHV-6 as triggering or aggravating factors in RRMS and PPMS, we compare their frequency in blood samples collected from 166 MS patients. The presence of herpes DNA was searched by real-time PCR (qPCR). The frequency of EBV and HHV-6 in MS patients were 1.8% (3/166) and 8.9% (14/166), respectively. Among the positive patients, 100% (3/3) EBV and 85.8% (12/14) HHV-6 are RRMS and 14.4% (2/14) HHV-6 are PPMS. Detection of EBV was 1.2% (2/166) and HHV-6 was 0.6% (1/166) in blood donors. About clinical phenotype of these patients, incomplete multifocal myelitis, and optic neuritis were the main CNS manifestations. These are the first data about concomitant infection of these viruses in MS patients from Brazil. Up to date, our findings confirm a higher prevalence in female with MS and a high frequency of EBV and HHV-6 in RRMS patients.

Do magnetic resonance imaging features differ between persons with multiple sclerosis of various races and ethnicities?

Those of African American or Latin American descent have been demonstrated to have more severe clinical presentations of multiple sclerosis (MS) than non-Latin American White people with MS. Concurrently, radiological burden of disease on magnetic resonance imaging (MRI) in African Americans with MS has also been described as being more aggressive. Here, we review MRI studies in diverse racial and ethnic groups (adult and pediatric) investigating lesion burden, inflammation, neurodegeneration, and imaging response to disease modifying therapy. We also discuss why such disparities may exist beyond biology, and how future studies may provide greater insights into underlying differences.

Demographics and baseline disease characteristics of Black and Hispanic patients with multiple sclerosis in the open-label, single-arm, multicenter, phase IV CHIMES trial

BACKGROUND

Black/African American patients with multiple sclerosis (BpwMS) and Hispanic/Latino patients with multiple sclerosis (HpwMS), who historically have been underrepresented in multiple sclerosis (MS) clinical trials, exhibit greater disease severity and more rapid disease progression than White patients with MS (WpwMS). The lack of diversity and inclusion in clinical trials, which may be due to barriers at the system, patient and study levels, impacts the ability to effectively assess risks, benefits and treatment responses in a generalized patient population.

METHODS

CHIMES (Characterization of Ocrelizumab in Minorities With Multiple Sclerosis), an open-label, single-arm, multicenter, phase IV study of self-identified BpwMS and HpwMS aged 18-65 years with relapsing MS and an Expanded Disability Status Score (EDSS) of ≤5.5, was developed in collaboration with patients with MS, national advocacy groups and clinical researchers. Patients were enrolled at study centers across the US, including Puerto Rico, and 1 site in Kenya.

RESULTS

A total of 182 patients enrolled in CHIMES: 113 (62.1%) were BpwMS, and 69 (37.9%) were HpwMS; the mean (SD) baseline EDSS score was 2.4 (1.4), and 62.6% of patients were treatment naive. Using the pooled non-BpwMS/HpwMS group in the OPERA ocrelizumab trials as a reference population, patients enrolled in CHIMES were younger, had a higher mean body mass and had a greater T2 lesion volume but similar T2 lesion number on MRI.

CONCLUSION

BpwMS and HpwMS have been consistently underrepresented in clinical trials, limiting the understanding of disease biology and response to treatment in this population. Data from the CHIMES study revealed differences in demographics and some baseline disease characteristics and disease burden between BpwMS and HpwMS vs WpwMS. These differences could have an impact when assessing clinical outcomes in BpwMS and HpwMS.

CLINICALTRIALS

GOV IDENTIFIER

NCT04377555.

Triggering multiple sclerosis at conception and early gestation: The variation in ultraviolet radiation is as important as its intensity

Background and objectives

Medical science needs to further elucidate the role of ultraviolet radiation (UVR), geographic latitude, and the role of vitamin D in the autoimmune disease multiple sclerosis (MS). We separated several papers into categories out of the thousands published and used their conclusions to explore the relationship between UVR and MS.

Relevance

MS is increasing in incidence, particularly in women where MS is two to three times that in men and particularly severe in African Americans.

Methods

We collected UVR data at our observatory in Central Maine and calculated the average coefficient of variation (CVUVR) for each month for 15 years (2007-2021, inclusive).

Results

The month of conception (MOC) is more important than the month of birth (MOB) in explaining how UVR triggers the variable genetic predisposition to MS. We hypothesize that the rapidly increasing CVUVR is important in preventing an increase in the activity of the vitamin D receptor (VDR) from August to December, which then requires a higher intensity of UVR later in life to suppress the immune system, therefore predisposing to more MS.

Limitations

One observatory at about 44° latitude.

Conclusions

While variation in UVR is important at the MOC if UVR exceeds a threshold (e.g., if the sunspot number equals or is greater than 90, usually at a solar cycle MAX, or at elevations above approximately 3,000 feet above sea level), the MS mitigating vitamin D-VDR mechanism is overwhelmed and the genotoxic effects of higher-intensity UVR promote MS in those with a genetic predisposition.

What is new in this research

This paper offers a new concept in MS research.

Understanding humoral immunity and multiple sclerosis severity in Black, and Latinx patients

People identified with Black/African American or Hispanic/Latinx ethnicity are more likely to exhibit a more severe multiple sclerosis disease course relative to those who identify as White. While social determinants of health account for some of this discordant severity, investigation into contributing immunobiology remains sparse. The limited immunologic data stands in stark contrast to the volume of clinical studies describing ethnicity-associated discordant presentation, and to advancement made in our understanding of MS immunopathogenesis over the past several decades. In this perspective, we posit that humoral immune responses offer a promising avenue to better understand underpinnings of discordant MS severity among Black/African American, and Hispanic/Latinx-identifying patients.

Health Disparities in Multiple Sclerosis among Hispanic and Black Populations in the United States

Multiple sclerosis (MS) is an acquired demyelinating disease of the central nervous system (CNS). Historically, research on MS has focused on White persons with MS. This preponderance of representation has important possible implications for minority populations with MS, from developing effective therapeutic agents to understanding the role of unique constellations of social determinants of health. A growing body of literature involving persons of historically underrepresented races and ethnicities in the field of multiple sclerosis is assembling. Our purpose in this narrative review is to highlight two populations in the United States: Black and Hispanic persons with multiple sclerosis. We will review the current understanding about the patterns of disease presentation, genetic considerations, response to treatment, roles of social determinants of health, and healthcare utilization. In addition, we explore future directions of inquiry as well as practical methods of meeting these challenges.

Effectiveness of ocrelizumab on clinical and MRI outcome measures in multiple sclerosis across black and white cohorts: A single-center retrospective study

OBJECTIVE

To examine differences in the therapeutic response to ocrelizumab in multiple sclerosis (MS) patients who self-identified as either White or Black, assessed longitudinally by expanded disability status scale (EDSS) progression and MRI brain volume loss.

METHODS

MS subjects treated with ocrelizumab were retrospectively identified. Clinical data were available for 229 subjects (White 146; Black 83) and MRI data from for 48 subjects (White 31; Black 17). Outcome measures were changes in the EDSS and brain volume over time. EDSS were analyzed as raw scores, ambulatory (EDSS <5.0) vs. ambulatory with assistance (5.5 ≤ EDSS ≤ 6.5) status, and EDSS severity (< 3.0, 3.0-5.0, and > 5.5 ≤ 6.5). General linear mixed model was used for statistical analysis. FreeSurfer was used for volumetric analysis.

RESULTS

The Black cohort had overrepresentation of females (78% vs. 62%, p = 0.013), lower age (median, 45 (IQR 39-51) vs. 49 (38-58), p = 0.08), lower Vitamin D levels (33 (21-45) vs. 40 (29-52), p = 0.002), and higher EDSS (4 (2-6) vs. 2.5 (1-6), p = 0.019). There was no progression of EDSS scores over the 2-year observation period. The covariates with significant influence on the baseline EDSS scores were older age, race, longer disease duration, prior MS treatment, and lower vitamin D levels. No differences were observed between the racial groups over time in the cortical, thalamic, caudate, putamen, and brainstem gray matter volumes nor in the cortical thickness or total lesion volume.

CONCLUSION

In this real-world clinical and radiological study, ocrelizumab treatment was highly effective in stabilizing clinical and MRI measures of disease progression in Blacks and Whites, despite higher baseline disability in the Black cohort.

Subtypes of relapsing-remitting multiple sclerosis identified by network analysis

We used network analysis to identify subtypes of relapsing-remitting multiple sclerosis subjects based on their cumulative signs and symptoms. The electronic medical records of 113 subjects with relapsing-remitting multiple sclerosis were reviewed, signs and symptoms were mapped to classes in a neuro-ontology, and classes were collapsed into sixteen superclasses by subsumption. After normalization and vectorization of the data, bipartite (subject-feature) and unipartite (subject-subject) network graphs were created using NetworkX and visualized in Gephi. Degree and weighted degree were calculated for each node. Graphs were partitioned into communities using the modularity score. Feature maps visualized differences in features by community. Network analysis of the unipartite graph yielded a higher modularity score (0.49) than the bipartite graph (0.25). The bipartite network was partitioned into five communities which were named fatigue, behavioral, hypertonia/weakness, abnormal gait/sphincter, and sensory, based on feature characteristics. The unipartite network was partitioned into five communities which were named fatigue, pain, cognitive, sensory, and gait/weakness/hypertonia based on features. Although we did not identify pure subtypes (e.g., pure motor, pure sensory, etc.) in this cohort of multiple sclerosis subjects, we demonstrated that network analysis could partition these subjects into different subtype communities. Larger datasets and additional partitioning algorithms are needed to confirm these findings and elucidate their significance. This study contributes to the literature investigating subtypes of multiple sclerosis by combining feature reduction by subsumption with network analysis.

Differential DNA methylation associated with multiple sclerosis and disease modifying treatments in an underrepresented minority population

Black and Hispanic American patients frequently develop earlier onset of multiple sclerosis (MS) and a more severe disease course that can be resistant to disease modifying treatments. The objectives were to identify differential methylation of genomic DNA (gDNA) associated with disease susceptibility and treatment responses in a cohort of MS patients from underrepresented minority populations. Patients with MS and controls with non-inflammatory neurologic conditions were consented and enrolled under an IRB-approved protocol. Approximately 64% of donors identified as Black or African American and 30% as White, Hispanic-Latino. Infinium MethylationEPIC bead arrays were utilized to measure epigenome-wide gDNA methylation of whole blood. Data were analyzed in the presence and absence of adjustments for unknown covariates in the dataset, some of which corresponded to disease modifying treatments. Global patterns of differential methylation associated with MS were strongest for those probes that showed relative demethylation of loci with lower M values. Pathway analysis revealed unexpected associations with shigellosis and amoebiasis. Enrichment analysis revealed an over-representation of probes in enhancer regions and an under-representation in promoters. In the presence of adjustments for covariates that included disease modifying treatments, analysis revealed 10 differentially methylated regions (DMR's) with an FDR <1E-77. Five of these genes (ARID5B, BAZ2B, RABGAP1, SFRP2, WBP1L) are associated with cancer risk and cellular differentiation and have not been previously identified in MS studies. Hierarchical cluster and multi-dimensional scaling analysis of differential DNA methylation at 147 loci within those DMR's was sufficient to differentiate MS donors from controls. In the absence of corrections for disease modifying treatments, differential methylation in patients treated with dimethyl fumarate was associated with immune regulatory pathways that regulate cytokine and chemokine signaling, axon guidance, and adherens junctions. These results demonstrate possible associations of gastrointestinal pathogens and regulation of cellular differentiation with MS susceptibility in our patient cohort. This work further suggests that analyses can be performed in the presence and absence of corrections for immune therapies. Because of their high representation in our patient cohort, these results may be of specific relevance in the regulation of disease susceptibility and treatment responses in Black and Hispanic Americans.

Disability outcomes in early-stage African American and White people with multiple sclerosis

BACKGROUND

Factors driving differences in disease burden between African American and White people with multiple sclerosis (pwMS) remain unclear. Here, we explored whether differences in disability outcomes could be observed after controlling for major sociodemographic factors and comorbidities, and assessed the presence of a possible interaction between MS and race.

METHODS

In this cross-sectional study, 120 pwMS within 6 years from disease onset and 82 healthy controls between 18 and 70 years of age, self-identified as either African American or White, were prospectively enrolled. Inclusion criteria for pwMS were: diagnosis of MS according to the revised McDonald criteria, relapsing-remitting phenotype and Expanded Disability Status Scale (EDSS) < 6.5. Study outcomes included: (i) global disability (EDSS); (ii) quantitative mobility and leg function (Timed 25 Foot Walk Test-T25FWT); (iii) quantitative finger dexterity (9-Hole Peg Test-9HPT); (iv) cognitive efficiency and speed performance (Symbol Digit Modalities Test-SDMT). Differences in disability outcomes were assessed employing multivariable linear regression models. Based on their association with MS or disability, covariates included age, gender, race, years of education, total income, body mass index, comorbidities. The interaction between MS and race on disability outcomes was estimated via relative excess risk of interaction and attributable proportion.

RESULTS

Accounting for age, gender, total income, education, body mass index and comorbidities, African American pwMS showed significantly worse performances in manual dexterity and cognition than White pwMS (White pwMS coeff. 3.24, 95% CI 1.55, 4.92 vs African American pwMS coeff. 5.52, 95% CI 3.55, 7.48 and White pwMS coeff. -5.87, 95% CI -8.86, -2.87 vs African American pwMS coeff. -7.99, 95% CI -11.58,-4.38). MS and race independently contributed to the observed gradient in disability severity.

CONCLUSIONS

Complex social disparities and systemic racism might contribute to clinical heterogeneity in MS.

Selective vulnerability of brainstem and cervical spinal cord regions in people with non-progressive multiple sclerosis of Black or African American and European ancestry

Background:

We evaluated imaging features suggestive of neurodegeneration within the brainstem and upper cervical spinal cord (UCSC) in non-progressive multiple sclerosis (MS).

Methods:

Standardized 3-Tesla three-dimensional brain magnetic resonance imaging (MRI) studies were prospectively acquired. Rates of change in volume, surface texture, curvature were quantified at the pons and medulla-UCSC. Whole and regional brain volumes and T2-weighted lesion volumes were also quantified. Independent regression models were constructed to evaluate differences between those of Black or African ancestry (B/AA) and European ancestry (EA) with non-progressive MS.

Results:

209 people with MS (pwMS) having at least two MRI studies, 29% possessing 3–6 timepoints, resulted in 487 scans for analysis. Median follow-up time between MRI timepoints was 1.33 (25th–75th percentile: 0.51–1.98) years. Of 183 non-progressive pwMS, 88 and 95 self-reported being B/AA and EA, respectively. Non-progressive pwMS demonstrated greater rates of decline in pontine volume ( p < 0.0001) in B/AA and in medulla-UCSC volume ( p < 0.0001) for EA pwMS. Longitudinal surface texture and curvature changes suggesting reduced tissue integrity were observed at the ventral medulla-UCSC ( p < 0.001), dorsal pons ( p < 0.0001) and dorsal medulla ( p < 0.0001) but not the ventral pons ( p = 0.92) between groups.

Conclusions:

Selectively vulnerable regions within the brainstem-UCSC may allow for more personalized approaches to disease surveillance and management.

social determinants of health in multiple sclerosis

Social determinants of health are the conditions in which people are born, grow, live, work and age. These circumstances are the non-medical factors that influence health outcomes. Evidence indicates that health behaviours, comorbidities and disease-modifying therapies all contribute to multiple sclerosis (MS) outcomes; however, our knowledge of the effects of social determinants — that is, the ‘risks of risks’ — on health has not yet changed our approach to MS. Assessing and addressing social determinants of health could fundamentally improve health and health care in MS; this approach has already been successful in improving outcomes in other chronic diseases. In this narrative Review, we identify and discuss the body of evidence supporting an effect of many social determinants of health, including racial background, employment and social support, on MS outcomes. It must be noted that many of the published studies were subject to bias, and screening tools and/or practical interventions that address these social determinants are, for the most part, lacking. The existing work does not fully explore the potential bidirectional and complex relationships between social determinants of health and MS, and the interpretation of findings is complicated by the interactions and intersections among many of the identified determinants. On the basis of the reviewed literature, we consider that, if effective interventions targeting social determinants of health were available, they could have substantial effects on MS outcomes. Therefore, funding for and focused design of studies to evaluate and address social determinants of health are urgently needed.

Here, the authors discuss the potential effects of social determinants of health on multiple sclerosis risk and outcomes. They suggest that addressing these determinants of health could substantially improve the lives of individuals with multiple sclerosis and call for more research.

Addressing an individual’s social determinants of health — that is, the conditions under which they are born, grow, live, work and age — could provide opportunities to reduce the burden of living with multiple sclerosis (MS).

Individual factors that may influence MS-related outcomes include sex, gender and sexuality, race and ethnicity, education and employment, socioeconomic status, and domestic abuse.

Societal infrastructures, including access to food, health care and social support, can also affect MS-related outcomes.

Awareness of the specific circumstances of a patient with MS might help neurologists deliver better care.

Social determinants of health are not static and can change according to wider sociopolitical contexts, as highlighted by the COVID-19 pandemic.

Rigorous studies of interventions to ameliorate the effects of poor social determinants on people with MS are urgently needed.

Social cognitive correlates of device-measured and self-reported physical activity in Black and White individuals with multiple sclerosis

BACKGROUND

There is increasing research interest regarding physical activity behavior among persons with multiple sclerosis (MS), yet there is little known about physical activity and its correlates in Black persons with MS.

OBJECTIVE

This cross-sectional study assessed associations among social cognitive theory (SCT) variables and device-measured and self-reported physical activity in samples of Black and White persons with MS.

METHODS

Participants included 67 Black and 141 White persons with MS who wore an ActiGraph accelerometer on a belt around the waist measuring moderate-to-vigorous physical activity (MVPA) for seven days and completed a battery of questionnaires. Questionnaires included demographic and clinical characteristics, leisure-time exercise, exercise self-efficacy, overcoming barriers self-efficacy, function, social support, exercise outcome expectations, and goal setting and planning.

RESULTS

Black participants with MS engaged in significantly less MVPA, but not sedentary behavior or light physical activity, than the White participants with MS. Black participants further had significantly lower levels of exercise self-efficacy and outcome expectations than the White sample. All SCT correlates were significantly correlated with self-reported physical activity, but only exercise and barriers self-efficacy, perceived function, and exercise goal setting were associated with device-measured MVPA. The difference in physical activity between Black and White participants with MS was accounted for by differences in exercise self-efficacy and outcome expectations.

CONCLUSIONS

Researchers should consider developing behavioral interventions that target exercise self-efficacy and outcome expectations as SCT variables for increasing physical activity in Black persons with MS.

Towards a global view of multiple sclerosis genetics

Multiple sclerosis (MS) is a neuroimmunological disorder of the CNS with a strong heritable component. The genetic architecture of MS susceptibility is well understood in populations of European ancestry. However, the extent to which this architecture explains MS susceptibility in populations of non-European ancestry remains unclear. In this Perspective article, we outline the scientific arguments for studying MS genetics in ancestrally diverse populations. We argue that this approach is likely to yield insights that could benefit individuals with MS from all ancestral groups. We explore the logistical and theoretical challenges that have held back this field to date and conclude that, despite these challenges, inclusion of participants of non-European ancestry in MS genetics studies will ultimately be of value to all patients with MS worldwide.

Epidemiology and Pathophysiology of Multiple Sclerosis

PURPOSE OF REVIEW

This article provides an overview of genetic, environmental, and lifestyle risk factors affecting the disease course of multiple sclerosis (MS) and reviews the pathophysiologic characteristics of both relapsing and progressive MS.

RECENT FINDINGS

The prevalence of MS has increased in recent decades, and costs of care for patients with MS have risen dramatically. Black, Asian, and Hispanic individuals may be at risk for more severe MS-related disability. Multiple genetic MS risk factors have been identified. Factors such as low vitamin D levels and a history of Epstein-Barr virus, smoking, and obesity, especially during childhood, also influence MS risk. Traditionally thought to be a T-cell-mediated disease, recent research has highlighted the additional roles of B cells and microglia in both relapsing and progressive MS.

SUMMARY

Complex interactions between genetic, environmental, and lifestyle factors affect the risk for MS as well as the disease course. People of color have historically been underrepresented in both MS clinical trials and literature, but current research is attempting to better clarify unique considerations in these groups. MS pathology consists of the focal inflammatory lesions that have been well characterized in relapsing MS, as well as a more widespread neurodegenerative component that is posited to drive progressive disease. Recent advances in characterization of both the inflammatory and neurodegenerative aspects of MS pathophysiology have yielded potential targets for future therapeutic options.

Pharmacokinetics/pharmacodynamics by race: Analysis of a peginterferon β-1a phase 1 study

BACKGROUND

Black/African American participants are underrepresented in clinical trials for multiple sclerosis but can experience a greater burden of disease than other racial groups in the United States. A phase 1, open-label, crossover study that demonstrated bioequivalence of subcutaneous and intramuscular injection of peginterferon β-1a in healthy volunteers enrolled similar proportions of Black and White participants, enabling a post hoc subgroup analysis comparing these groups.

METHODS

Peginterferon β-1a (125 μg) was administered by subcutaneous or intramuscular injection, followed by a washout period before a second injection using the alternative method. The primary pharmacokinetic and pharmacodynamic endpoints were maximum observed concentration (C_max) and area under the concentration-time curve from hour 0 to infinity (AUC_inf) of study drug and serum concentration of neop-terin, respectively. Safety and tolerability were included as secondary endpoints.

FINDINGS

This analysis included 70 (51.5%) Black and 59 (43.3%) White participants. Peginterferon β-1a C_max was 29.8% higher in Black than in White participants following subcutaneous administration but was similar following intramuscular administration. Mean AUC_inf was 31.0% and 11.8% greater in Black than in White participants with subcutaneous and intramuscular administration, respectively. Pharmacodynamics and safety signals were similar between groups, although Black participants reported numerically fewer adverse events.

CONCLUSIONS

No clinically meaningful differences were identified between Black and White participants related to peginterferon β-1a administration, supporting the approved dose of 125 μg/mL peginterferon β-1a. Future clinical studies should include sufficiently diverse populations to ensure accurate assessments of treatment response.

FUNDING

Funding for medical writing support was provided by Biogen (Cambridge, MA, USA).

Advancing Care and Outcomes for African American Patients With Multiple Sclerosis

Multiple sclerosis (MS) has historically been underdiagnosed and undertreated among African Americans. Recent evidence suggests that African Americans with MS have a different clinical presentation, increased disease incidence and burden, and worse long-term outcomes vs their White counterparts. Due to limited data available for African Americans in MS clinical trials, it is difficult to make informed, generalizable conclusions about the natural history, prognosis, and therapeutic response in this population. In this narrative review, we highlight the nature and magnitude of the health disparities experienced by African Americans with MS and underscore the pressing need to increase knowledge about and understanding of MS disease manifestations in this group. In addition, we describe the mission and objectives of the recently established National African Americans with Multiple Sclerosis Registry, which is intended to be a platform to advance the care of African Americans with MS and address health disparities they may experience.

A Fuzzy Expert System for Early Diagnosis of Multiple Sclerosis

BACKGROUND

Artificial intelligence plays an important role in medicine. Specially, expert systems can be designed for diagnosis of disease.

OBJECTIVE

Artificial intelligence can be used for diagnosis of disease. This study proposes an expert system for diagnosis of Multiple Sclerosis based on clinical symptoms and demographic characteristics. Specially, it recommends patients to refer to a specialist for further investigation.

MATERIAL AND METHODS

In this empirical study, some symptoms of Multiple Sclerosis are mapped to fuzzy sets. Moreover, several rules are defined for prediction of Multiple Sclerosis. The fuzzy sets and rules form the knowledge base of the expert system. Patients enter their symptoms and demographic information via a user interface and Mamdani method is used in inference engine to produce the appropriate recommendation.

RESULTS

The precision, recall, and F-measure are used as criteria to analyze the efficiency of the expert system. The results show that the designed expert system can recommend patients for further investigation as effective as specialists. Specially, while the proposed expert system recommended referring to a doctor for some healthy users, most of the MS patients are diagnosed.

CONCLUSION

The proposed expert system in this study can analyze the symptoms of patients to predict the Multiple Sclerosis disease. Therefore, it can investigate initial status of patients in a rapid and cost-effective manner. Moreover, this system can be applied in situations and places, which human experts are unavailable.

Differences in Cardiometabolic Comorbidities Between Black and White Persons Living With Multiple Sclerosis

OBJECTIVE

To determine differences in obesity, type 2 diabetes, and hypertension in Black patients compared with White patients with multiple sclerosis (MS).

DESIGN

Cross-sectional database review.

SETTING

Large academic medical center research records database.

PARTICIPANTS

A total of 3191 patient cases (N=3191; 77% female, 34% Black) identified by MS diagnosis within the medical record.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Diagnosis codes for type 2 diabetes and hypertension. Body mass index (BMI), race, age, and sex were collected. Analysis of variance (continuous variables) and chi-square analyses (categorical variables) were conducted to determine differences in obesity, diabetes, and hypertension between race and sex. Logistic regression was conducted to determine odds ratios (ORs) of developing diabetes and hypertension based on race, sex, BMI, and age.

RESULTS

Black patients were more than twice as likely to be diagnosed as having diabetes (OR, 2.15 [95% CI, 1.70-2.72]; P<.0001) or hypertension (OR, 2.44 [95% CI, 2.05-2.91], P<.0001) compared with White patients. Sex did not present a greater likelihood of being diagnosed as having diabetes; however, men were 1.22 times more likely be diagnosed as having hypertension compared with women (95% CI, 1.01-1.49; P=.0439). Increased age and BMI were also significantly associated with likelihood of diagnosis of diabetes and hypertension (age: diabetes OR, 1.05 [95% CI, 1.04-1.06], P<.0001; hypertension OR, 1.06 [95% CI, 1.05-1.06], P<.0001; BMI: diabetes obese vs normal: OR, 2.11 [95% CI, 1.43-3.11], P=.0002; hypertension: obese vs normal: OR, 1.72 [95% CI, 1.39-2.13], P<.0001).

CONCLUSIONS

Black patients with MS are significantly more likely to have cardiometabolic conditions than White patients. These conditions have been associated with poorer health outcomes for people with MS and may have some effect on the differences in MS disease course reported in Black patients.

Multilocus evaluation of genetic predictors of multiple sclerosis

BACKGROUND

Genome-wide association studies identified numerous susceptibility loci for multiple sclerosis in populations of European ancestry, but the associations are not always reproducible in other populations due to admixture and different linkage disequilibrium patterns obscuring true association signals.

OBJECTIVE

Our aim was to identify genetic predictors of multiple sclerosis in three ethnically homogenous populations from the Volga-Ural region of Russian Federation.

METHODS

In the largest to date study of multiple sclerosis in Russian population, involving 2048 participants from the Republic of Bashkortostan, Russian Federation (641 patients with multiple sclerosis and 1407 unaffected individuals), we performed replication analysis of previously identified genome-wide signals for multiple sclerosis. Associations were tested using logistic regression analysis under additive genetic model adjusted for sex. Meta-analysis of the study results in three populations was performed under fixed effects and random effects models.

RESULTS

We demonstrate the association with multiple sclerosis of the five variants (INAVA rs7522462, EOMES rs11129295, C6orf10 rs3129934, CD86 rs9282641, and GPR65 rs2119704). The strongest association (OR = 2.16, CI:1.85-2.74, P = 2.53x10^-13) was detected for rs3129934 polymorphism in the major histocompatibility region. Multilocus analysis has revealed 322 and 27 allelic patterns associated with multiple sclerosis in women and men, respectively. In women, the highest risk of MS was conferred by C6orf10 rs3129934*T/T + STAT3 rs744166*T combination (OR = 11.87), in men - by C6orf10 rs3129934*T + EOMES rs11129295*C + RPS6KB1 rs180515*C combination (OR = 3.25).

CONCLUSION

We confirm five associations with multiple sclerosis previously reported in genome-wide scans in Europeans in three ethnic groups from the Volga-Ural region of Russia.

Effect of Obesity on Retinal Integrity in African Americans and Caucasian Americans With Relapsing Multiple Sclerosis

Objective: To study the effect of obesity on retinal structures in African Americans (AAs) and Caucasian Americans (CAs) with relapsing-remitting multiple sclerosis (RRMS).

Methodology: About 136 patients with RRMS without history of optic neuritis were divided into two groups, based on body mass index (BMI): 67 obese (40 AA, 27 CA, mean BMI ± SD: 36.7 ± 5.8), and 69 non-obese (23 AA, 46 CA, mean BMI ± SD: 24.0 ± 3.1). The peripapillary retinal nerve fiber layer (pRNFL) thickness was quantified by optical coherence tomography (OCT) and was segmented into quadrant thickness: superior (S), inferior (I), temporal (T), and nasal (N). Papillomacular bundle (PMB) thickness, retinal nerve fiber layer (RNFL), ganglion cell + inner plexiform layer (GCIPL), inner nuclear (INL), outer plexiform (OPL), outer nuclear (ONL), and total macular (TMV) volumes were obtained.

Results: Obesity was associated with lower T thickness (58.54 ± 15.2 vs. 61.9 12.4, p = 0.044), higher INL (0.98 ± 0.07 vs. 0.96 ± 0.06, p = 0.034), and lower RNFL (0.77 ± 0.14 vs. 0.82 ± 0.12, p = 0.009) volumes. Obese AA had significantly thinner T (58.54 ± 15.19 vs. 61.91 ± 12.39, p = 0.033), N (68.94 ± 2.7 vs. 77.94 ± 3.3, p = 0.044), and TMV (8.15 ± 0.07 vs. 8.52 ± 0.09, p = 0.003), RNFL (0.74 ± 0.02 vs. 0.82 ± 0.02, p = 0.013), OPL (0.76 ± 0.01 vs. 0.79 ± 0.1, p = 0.050), ONL (1.68 ± 0.031 vs. 1.79 ± 0.038, p = 0.026), and GCIPL (1.78 ± 0.04 vs. 1.9 ± 0.05, p = 0.038) compared to obese CA. Among patients with non-obesity, the ONL was significantly lower in AA (1.78 ± 0.04 vs. 1.9 ± 0.05, p < 0.001).

Conclusions: Obesity is associated with retinal structure abnormalities in patients with RRMS. Its impact might be more prominent in AA than CA. Large longitudinal studies are needed to validate our findings.

Comparison of Dimethyl Fumarate vs Fingolimod and Rituximab vs Natalizumab for Treatment of Multiple Sclerosis

Importance

As disease-modifying treatment options for multiple sclerosis increase, comparisons of the options based on real-world evidence may guide clinical decision-making.

Objective

To compare the relapse outcomes between 2 pairs of disease-modifying treatments: dimethyl fumarate vs fingolimod and natalizumab vs rituximab.

Design, Setting, and Participants

This comparative effectiveness study integrated data from a clinic-based multiple sclerosis research registry and its linked electronic health records (EHR) system between January 1, 2006, and December 31, 2016, and built treatment groups for each pairwise disease-modifying treatment comparison according to both registry records and electronic prescriptions. Parallel analyses were conducted from October 11, 2019, to July 7, 2021.

Main Outcomes and Measures

The main outcomes were the 1-year and 2-year relapse rates as well as the time to relapse. To compare relapse outcomes, the study adjusted for covariates from 2 sources (registry and EHR) and corrected for confounding biases among the covariates by the doubly robust estimation.

Results

The study included 4 treatment groups: dimethyl fumarate (n = 260; 198 women [76.2%]; 227 non-Hispanic White individuals [87.3%]; mean [SD] age at diagnosis, 41.7 [10.4] years), fingolimod (n = 267; 190 women [71.2%]; 222 non-Hispanic White individuals [83.1%]; mean [SD] age at diagnosis, 37.9 [9.9] years), natalizumab (n = 204; 160 women [78.4%]; 172 non-Hispanic White individuals [84.3%]; mean [SD] age at diagnosis, 37.2 [10.6] years), and rituximab (n = 115; 83 women [72.2%]; 99 non-Hispanic White individuals [86.1%]; mean [SD] age at diagnosis, 44.1 [11.1] years). No significant differences were found in the relapse outcomes between dimethyl fumarate and fingolimod after correcting for confounding biases and multiple testing (difference in 1-year relapse rate, 0.028 [95% CI, -0.031 to 0.084]; difference in 2-year relapse rate, 0.071 [95% CI, 0.008-0.128]; relative risk of 2-year non-relapse, 0.957 [95% CI, 0.884-1.035] with dimethyl fumarate as reference). When compared with rituximab, natalizumab was associated with a higher relapse rate for all 3 outcomes after bias correction and multiple testing (difference in 1-year relapse rate, 0.080 [95% CI, 0.013-0.137]; difference in 2-year relapse rate, 0.132 [95% CI, 0.043-0.189]; relative risk of 2-year non-relapse, 0.903 [95% CI, 0.822-0.944]). Confounders were identified from EHR data not recorded in the registry data through data-driven feature selection.

Conclusions and Relevance

This study reports real-world evidence of equivalent relapse outcomes between dimethyl fumarate and fingolimod and relapse reduction in favor of rituximab relative to natalizumab. This approach illustrates the value of incorporating EHR data as high-dimensional covariates in real-world treatment comparison.

Liver kinase B1 rs9282860 polymorphism and risk for multiple sclerosis in White and Black Americans

BACKGROUND

We previously reported that the single nucleotide polymorphism (SNP) rs9282860 in serine threonine kinase 11 (STK11) gene which codes for liver kinase B1 (LKB1) has higher prevalence in White relapsing-remitting multiple sclerosis (RRMS) patients than controls. However it is not known if this SNP is a risk factor for MS in other populations.

METHODS

We assessed the prevalence of the STK11 SNP in samples collected from African American (AA) persons with MS (PwMS) and controls at multiple Veterans Affairs (VA) Medical Centers and from a network of academic MS centers. Genotyping was carried out using a specific Taqman assay. Comparisons of SNP frequencies were made using Fisher's exact test to determine significance and odds ratios. Group means were compared by appropriate t-tests based on normality and variance using SPSS V27.

RESULTS

There were no significant differences in average age at first symptom onset, age at diagnosis, disease duration, or disease severity between RRMS patients recruited from VAMCs versus non-VAMCs. The SNP was more prevalent in AA than White PwMS, however only in secondary progressive MS (SPMS) patients was that difference statistically significant. AA SPMS patients had higher STK11 SNP prevalence than controls; and in that cohort the SNP was associated with older age at symptom onset and at diagnosis.

CONCLUSIONS

The results suggest that the STK11 SNP represents a risk factor for SPMS in AA patients, and can influence both early (onset) and later (conversion to SPMSS) events.

Perceptions and Preferences Regarding Multiple Sclerosis Research Among Racial and Ethnic Groups

BACKGROUND

For unclear reasons, minorities have been historically underrepresented in multiple sclerosis (MS) clinical trials. We hypothesized that different perceptions and preferences about research participation among racial and ethnic groups contribute to this imbalance.

METHODS

Members of the MS Minority Research Engagement Partnership Network developed a Web-based survey in English and Spanish on research impressions, concerns, and preferences regarding study attributes among people with MS. Invitations to take the survey were distributed by network members and partner organizations.

RESULTS

We included 2599 participants with MS (2111 White, 215 African American; 188 Hispanic). Consistently disliked study attributes included potential harms to health and confusing study information. Compared with White and non-Hispanic participants, respectively, African American (odds ratio [OR] = 2.05, P ≤ .001) and Hispanic (OR = 1.79, P = .003) participants were more concerned about being used by the research team. Hispanic participants were more concerned about research participation carrying risks to their legal status (OR = 1.70, P = .001). Hispanic (OR = 3.18, P ≤ .001) and African American (OR = 5.51, P ≤ .001) participants were more likely to prefer for the study to benefit their own racial/ethnic group. A top concern across all groups was not being fully informed about the research.

CONCLUSIONS

We found strong support for research across racial and ethnic groups; however, minority groups have specific concerns regarding mistrust, receiving poor-quality care, unemployment, health insurance, and legal status. Investigators wanting to recruit a diverse study population are advised to show how they have addressed these concerns and to communicate how the research will advance the science and literature and result in better care and/or other benefits to underrepresented communities.

Association of Disease Severity and Socioeconomic Status in Black and White Americans With Multiple Sclerosis

OBJECTIVE

To compare clinical and imaging features of multiple sclerosis (MS) severity between Black Americans (BA) and White Americans (WA) and evaluate the role of socioeconomic status.

METHODS

We compared BA and WA participants in the Multiple Sclerosis Partners Advancing Technology Health Solutions (MS PATHS) cohort with respect to MS characteristics including self-reported disability, objective neurologic function assessments, and quantitative brain MRI measurements, after covariate adjustment (including education level, employment, or insurance as socioeconomic indicators). In a subgroup, we evaluated within-race, neighborhood-level indicators of socioeconomic status (SES) using 9-digit ZIP codes.

RESULTS

Of 1,214 BAs and 7,530 WAs with MS, BAs were younger, had lower education level, and were more likely to have Medicaid insurance or be disabled or unemployed than WAs. BAs had worse self-reported disability (1.47-fold greater odds of severe vs. mild disability, 95% CI 1.18, 1.86) and worse performances on tests of cognitive processing speed (-5.06 fewer correct, CI -5.72, -4.41), walking (0.66 seconds slower, 95% CI 0.36, 0.96) and manual dexterity (2.11 seconds slower, 95% CI 1.69, 2.54). BAs had more brain MRI lesions and lower overall and gray matter brain volumes, including reduced thalamic (-0.77 mL, 95% CI -0.91, -0.64), cortical (-30.63 mL, 95% CI -35.93, -25.33), and deep (-1.58 mL, 95% CI -1.92, -1.23) gray matter volumes. While lower SES correlated with worse neuroperformance scores in WAs, this association was less clear in BA.

CONCLUSION

We observed a greater burden of disease in BAs with MS relative to WAs with MS, despite adjustment for SES indicators. Beyond SES, future longitudinal studies should also consider roles of other societal constructs (e.g., systemic racism). Such studies will be important for identifying prognostic factors and optimal treatment strategies among BAs with MS is warranted.

Multiple sclerosis in Kenya: Demographic and clinical characteristics of a registry cohort

Background

Multiple Sclerosis (MS) is the leading cause of non-traumatic neurological disability in young adults. There is limited literature regarding the burden of MS in sub-Saharan Africa (SSA).

Objective

To describe the demographic and clinical characteristics of patients with MS (PwMS) presenting to a tertiary referral hospital in Nairobi.

Methods

We conducted a retrospective descriptive study for PwMS presenting to Aga Khan University Hospital, Nairobi from 2008–2018.

Results

99 cases met the diagnostic criteria for MS with a male to female ratio of 1:4. Majority (68.7%) of PwMS were indigenous Africans with a mean age of onset of 30.7 years. Mean duration from symptom onset to first neuro-imaging was 5.04 years. Only 33% of patients had sensory symptoms at onset whereas 54.5% had vitamin D deficiency/insufficiency. Majority (79.5%) had relapsing remitting MS (RRMS) and 56.6% were initiated on disease modifying therapy (DMT). Only 21.2% of patients on DMT were non-compliant. Patients with RRMS were more likely to be initiated on DMT at our hospital (p < 0.001).

Conclusion

Clinical characteristics of these patients largely resemble those of other SSA cohorts and African American patients. There was a delay between symptom onset and neuroimaging. There were also issues with DMT compliance.

Cortical surface thickness, subcortical volumes and disability between races in relapsing-remitting multiple sclerosis

BACKGROUND

The interplay between cortical surface thickness (CTh), subcortical volumes (SCV) and disability in patients with relapsing remitting multiple sclerosis (RRMS) is still not clear.

OBJECTIVE

To examine the relationship between CTh, SCV, and disability and investigate differences in CTh, SCV and disability between African Americans (AA) and Caucasian Americans (CA).

METHODS

Sixty-five RRMS (33AA, 32 CA) participants underwent Expanded Disability Status Scale and Multiple Sclerosis Functional Composite (MSFC) assessments, including timed 25-foot walk (T25FW), nine-hole peg test (9HPT) on dominant (D) and non-dominant hand (ND) and paced auditory serial addition test (PASAT-3). Symbol digit modalities test (SDMT) was also administered. All participants underwent 3T brain MRI. CTh was measured in the Frontal (FA), Parietal (PA), Temporal (TA), Occipital (OA), Cingulate (CA), and Global (GA) cortical surface areas (CSA). SCV measurements included Thalamus (TV), Caudate (CV), Putamen (PV), Pallidum (PaV), Hippocampus (HV), Amygdala (AV), Accumbens (AcV), Brain Stem (BSV), and Deep Gray Matter Total Volume (DGMTV). A general linear model with multivariate analysis (MANOVA) was used to determine the differences between the two cohorts (SPSS vs 25). Spearman rank correlation analysis was performed to investigate the relationship between CTh and MSFC.

RESULTS

AA have significantly decreased FA, PA, TA, GA CTh compared to CA (p = 0.004, p = 0.018, p = 0.013, p = 0.015, respectively). SCV measurements were not significantly different. Only in CA, the MSFC measures correlate significantly with regional CSA CTh. In both races and in the entire group, T25FW correlates with TV, PV, AV, AcV and DGMTV (p < 0.05). Only in AA and the entire cohort, PASAT-3 correlates with TV and AcV(p = 0.041, p = 0.006, p = 0.006, p = 0.000 respectively).

CONCLUSIONS

Differences in CSA CTh reinforce the different disease pathobiology between AA and CA. Regional CTh may represent a useful biomarker related to multi-domain disability only in CA, while in AA DGM injury might be a more important contributor to disability. Longitudinal, large-scale studies are warranted to confirm our findings.

Early Aggressive Treatment Approaches for Multiple Sclerosis

Purpose of review

This review presents a comprehensive analysis of the current high-efficacy disease-modifying therapies (DMTs) available for treatment of multiple sclerosis (MS). We discuss the existing approved and emerging therapeutics in patients with relapsing and progressive forms of MS using data from clinical trials and observational studies. Treatment considerations in pediatric and pregnant populations are also reviewed. Finally, we discuss the treatment paradigms of the escalation and early aggressive approaches to treatment of MS, with review of ongoing clinical trials to compare these approaches.

Recent findings

Natalizumab has shown promising data on efficacy in not only randomized trials but also observational studies when compared with placebo, the injectable DMTs, and fingolimod. The anti-CD20 B cell depleting therapies (rituximab, ocrelizumab, and ofatumumab) have also demonstrated superiority in randomized clinical trials compared to their comparator group (placebo, interferon, and teriflunomide, respectively) and rituximab has shown in observational studies to be more effective than older injectable therapies and some of the oral therapies. Alemtuzumab has shown good efficacy in randomized controlled trials and observational studies yet has several potentially severe side effects limiting its use. Mitoxantrone has similarly demonstrated significant reduction in new disease activity compared to placebo but is rarely used due to its severe side effects. Cladribine is an oral DMT often grouped in discussion with other higher efficacy DMTs but may be slightly less effective than the other therapies described in this review. Many emerging targets for therapeutic intervention are currently under investigation that may prove to be beneficial in early aggressive MS, including autologous hematopoietic stem cell transplantation.

Summary

Traditionally, MS has been treated with an escalation approach, starting patients on a modestly effective DMT and subsequently escalating to a higher efficacy DMT when there is evidence of clinical and/or radiologic breakthrough activity. With the development of higher efficacy therapies and emerging data showing the potential positive long-term impact of these therapies when started earlier in the disease course, many clinicians have shifted to an early aggressive treatment approach in which patients are initially started on a higher efficacy DMT. Two clinical trials, the TRaditional versus Early Aggressive Therapy for MS (TREAT-MS) trial and the Determining the Effectiveness of earLy Intensive Versus Escalation approaches for the treatment of Relapsing-remitting MS (DELIVER-MS) trial, aim to directly compare these treatment strategies and their impact on clinical and radiologic outcomes.

Efficacy and safety of ocrelizumab vs interferon beta-1a in participants of African descent with relapsing multiple sclerosis in the Phase III OPERA I and OPERA II studies

BACKGROUND

People of African descent with multiple sclerosis (MS) appear to have a more severe disease course and may have an attenuated response to some medications compared with people of European descent.

METHODS

This is a post hoc subgroup analysis of participants of African descent with relapsing forms of MS who were enrolled in the Phase III OPERA I or OPERA II clinical trials and treated with ocrelizumab (OCR) 600 mg every 6 months or interferon beta-1a (IFN β-1a) 44 μg 3 times per week.

RESULTS

Among the 1,656 participants enrolled in OPERA I and II, 72 (4.3%) were of African descent (OCR, 40; IFN β-1a, 32). A trend for reduction in annualized relapse rate (ARR) was observed in participants of African descent, with an ≈50% reduction with OCR vs IFN β-1a. The relative rate of the mean number of gadolinium-enhancing lesions on magnetic resonance imaging (MRI) was 0.04 (95% CI, 0.01-0.22; p=0.001) in participants of African descent treated with OCR compared with IFN β-1a. Similarly, the relative rate of the number of new or enlarging T2 lesions on MRI was 0.14 (95% CI, 0.06-0.32; p<0.001). In participants of African descent, those treated with OCR were 2.61 times more likely than those who received IFN β-1a to be classified as having no evidence of disease activity (95% CI, 1.24-5.49; p=0.003) and 4.17 times more likely to be classified as having no evidence of disease activity or progression (95% CI, 1.27-13.65; p=0.006). African-descent participants tended to have a greater radiographic burden of disease at baseline, develop more brain lesions when treated with IFN β-1a, and be at greater risk of disability progression than non-African-descent participants. Participants of African descent experienced slightly more adverse events, serious adverse events, and hypersensitivity reactions than non-African-descent participants.

CONCLUSION

In this small sample of participants of African descent with relapsing MS from the OPERA studies, OCR demonstrated treatment benefits in clinical, MRI, and composite efficacy outcomes vs IFN β-1a, consistent with what was observed in the complete OPERA intention-to-treat cohorts.

MS and Disability Progression in Latin America, Africa, Asia and the Middle East: A Systematic Review

BACKGROUND

There is evidence of an increased prevalence and disease burden of Multiple Sclerosis (MS) in parts of the world where the risk was once considered low, such as Latin America (LA), Sub-Saharan Africa, Asia and the Middle East-North Africa (MENA). Despite the growing number of clinical reports, the phenotype and course of MS in these regions remains understudied compared with Europe and North America. We aimed to investigate MS phenotypes and long-term clinical outcomes across these regions.

METHOD

A Boolean search of the medical literature was conducted between January 1980 and April 30, 2020. PubMed, SCOPUS, Global Health, and the Cochrane databases, were used to identify all relevant citations. Articles were collated and managed on Covidence® software. We independently appraised the articles for meeting study criteria and for quality using the Critical Appraisal Skills Program (CASP) and the Specialist Unit for Review Evidence (SURE) system.

RESULTS

A total of 1,639 studies were imported for screening. After removing 545 duplicates, two authors assessed 1,094 abstracts and selected 515 for full-text screening. 72 articles met study criteria, including 19 studies from LA, 4 from sub-Saharan Africa, 24 from Asia and 25 from MENA. The overall sex ratio was 2.5:1 (female: male). Disability was assessed using the Expanded Disability Status Scale (EDSS). Longitudinal disability progression and time to standard endpoints was compared by region and with relevant Western reports. Patients with MS living in the MENA region appear to reach disability milestones faster than those in the Western world, although this finding is not uniform. South Asia shows distinct disability features compared with East Asia, more closely resembling those of the West. Disease morbidity in East Asia appears more benign than in the West after careful exclusion of neuromyelitis optica spectrum disorder cases. Populations in LA tend to have similar MS features to the Western world, but some exceptions exist, including African descendants that reach disability milestones earlier. Using all studies with appropriate survival analysis, the mean time to EDSS 6.0 was 16.97 years with a heterogeneity index of 24.59.

CONCLUSION

The clinical phenotypes and disability progression of MS in LA, Africa, Asia and the MENA region have similarities to Western MS. In some regions and subpopulations there is evidence of a more aggressive course, possibly due to a combination of genetic and environmental factors. More population-based longitudinal data are needed, particularly in Sub-Saharan Africa.