Exploring Multiple Sclerosis Disparities: A Focus on Black and Hispanic Populations in the US

A review published in Biomedicines of the underrepresentation of Black and Hispanic persons with multiple sclerosis (MS) in research reveals unique disease patterns, genetic factors, treatment response, social determinants of health, health care utilization, and potential future directions for inquiry. 

“The role of genetic and biological determinants of health has long been understudied and therefore underrecognized,” said researchers. “Race and ethnicity are also associated with genetic ancestry and therefore indirectly related to genetic variants that may affect disease and health outcomes in MS.” 

Using the Texas Medical Center Library OneSearch and Pubmed, a literature search was conducted for English language studies related to "multiple sclerosis", "disparities", "social determinants of health", "African-American", "Black", "Hispanic", "Latino", and "LatinX" from 2014 to October 2022. Similar searches were done periodically in subsequent reviews; additional studies were reviewed based on reference lists of relevant studies and emerging elements of interest from the literature review.  

The paper utilized the racial/ethnic designations of Black, Hispanic, and White, substituting terms like "African-American," "Non-Hispanic Black," "Non-Hispanic White," and "Hispanic" for accuracy and specificity. These populations were prioritized due to their highest representation of MS disease burden in the US.  

Historically, it was believed that MS was more common among White individuals of European background than minority groups like Black individuals. However, recent studies show that Black individuals have higher rates of MS and may experience a more severe form of the disease with higher levels of disability. They are often diagnosed at a younger age and have faster disease progression, requiring ambulatory assistance sooner. Black patients also exhibit more cognitive, ambulatory, and manual dexterity impairments.  

The available literature on MS in Hispanic individuals is limited compared to that of White and Black individuals in the US. Population studies indicate that Hispanics have a lower incidence and prevalence of MS compared to White and Black Americans. However, morbidity and disease severity studies show inconsistencies, with some indicating earlier onset and more frequent myelitis presentations among Hispanics, while others show higher disability levels. These findings suggest that there may be variations in the type and degree of morbidity associated with MS in Hispanic populations. 

Research has shown that genetic factors, particularly variations in the HLA complex genotypes, play a significant role in the development of MS. While researchers have mostly focused on individuals of European ancestry, recent research has expanded to include different races and ethnicities, revealing conflicting results in disease risk, and highlighting the importance of further research in minority populations for personalized MS treatment.  

Limited studies exist on the clinical course of MS in minority populations, particularly regarding the effectiveness and tolerability of disease-modifying treatments. Preliminary findings suggest increased disease progression and adverse reactions in Black individuals treated with interferon-β-1a, while other treatments like natalizumab and ocrelizumab show similar benefits and more adverse events in Black participants, emphasizing the need for more research and diverse representation in future trials. 

There are significant disparities in social determinants of health across racial groups in MS. Minority populations, such as Black and Hispanic individuals, have lower health care access and utilization than Whites, both in general neurologic care and specifically in MS care. Income and socioeconomic disadvantage also play a crucial role in impacting morbidity and management in MS, with lower income linked to higher disability and cognitive issues. Additionally, there are differences in how health care and MS research participation are perceived among Black and Hispanic individuals, highlighting the need for tailored approaches and increased research to address these disparities in MS care. 

Emerging literature suggests that Hispanic and Black people with MS (pwMS) experience unique characteristics and disparities compared to White pwMS, including genetic and risk factors. To better address these disparities, health care professionals should receive education about MS in minority populations, increase enrollment of minority pwMS in research efforts, and make practical adjustments in care strategies to improve health care utilization and accessibility.  

“Discrepancies in socioeconomic constructs are becoming important interventional targets to help alleviate disease severity by race and ethnicity,” said researchers. “While further research remains a high priority in this field, evidence now exists to guide improvements in the delivery of MS care to historically underserved minority populations.” 

Reference  

Moore MZ, Pérez CA, Hutton GJ, et al. Health disparities in multiple sclerosis among Hispanic and black populations in the United States. Biomedicines. 2023; 11(4):1227. doi:10.3390/biomedicines11041227