MS in Minority Populations

Why is this article important? 

LiveWiseMS.org generally reviews recent articles from medical journals, but this article published in 2015 remains an important reminder of how data can and should dispel perceptions based on generalizations.  In this instance, many people believe that MS is less common among people of African and Hispanic descent compared to people of northern European ancestry.  A study published as late as 2013 suggested that MS is more common among people of northern European descent and less common among people of African or Latino ancestry.  This observation, of course, mirrors the notion that MS occurs more frequently in areas distant from the equator and therefore receive less exposure to vitamin D-generating sunlight.  Do the data, however, support this common belief? 

To be fair, multiple sclerosis results from complex interactions among our genetic predisposition, gender, and environment.  Even had previous investigators agreed that race might represent another important factor in understanding MS, they may have decided that racial identity overlapped too closely with the known factors of genes, gender, and environment.  In recent years, investigators have begun to explore the implications of race in understanding the incidence, disease course, and response to disease-modifying therapies among people of African and Latino ancestry.  Interestingly, a study published in 2011 suggested that people of African and Latino ancestry living in the United States may have a higher incidence of MS than populations in their countries of origin.  This observation raises two intriguing questions:  first, what do we know about MS among brown and black people, and, second, what aspects of living in the United States may contribute to a higher incidence of MS?  

If genes and gender are well defined, the third factor, environment, may invite more thought.  For most of us, thinking about environment brings to mind such factors as climate, living conditions, diet, activity levels, and health care.  We are less likely to consider factors that present more difficulties to quantify but may influence environment in important ways.  In this article, the authors review previous studies to provide more insight into our understanding of MS among minority populations.   

How did the researchers study this issue? 

An obvious first step for the authors was to determine how much data have been accumulated in studying MS in black and Latino populations.  At that time, at least, the answer was not a great deal.   As of January 2014, only 1% or 136 out of about 60,000 MS studies focused on black and Latino people with MS.   Moreover, a study published that year of 496 newly diagnosed individuals in the Kaiser Permanente health system produced data that flew in the face of earlier statements that MS was less common among African Americans.  Data from this study found an incidence rate of MS per 100,000 persons among African Americans of 10.2%, exceeding the rates for Caucasian Americans (6.9%), Hispanic Americans (2.9%), and Asian Americans (1.4%).  These data resembled those of a 2012 study of 2,691 Gulf War-era veterans with MS, which found an incidence per 100,000 rate of 12.1 among African Americans compared to 9.3 among Caucasian Americans, 8.2 among Hispanic Americans, and 3.3 among Asian Americans.   

These data at the very least cast a great deal of doubt on the belief that people of African descent are less likely to develop MS than their peers of northern European descent.  What, then, do the data, albeit limited, suggest about the course of MS among African Americans?   

Most data suggest that African Americans experience a more aggressive disease course with more frequent relapses, poorer post-relapse recoveries, faster transition from relapsing-remitting MS (RRMS) to secondary progressive MS, and more severe ambulatory impairment compared with Caucasian Americans.  It is possible, the authors suggest, that people of African descent have a stronger autoimmune response than people with other ancestries.  Other studies have pointed to such potential factors as a larger number of T1 and T2 spinal cord lesions among people of African ancestry.   

Data, then, suggest there may be a genetic predisposition among people of African descent driving a more aggressive form of MS, but what about that 2011 study suggesting that black people living in the United States may have higher incidence of MS than those in their countries of origin?  What about their environment in the US helps to drive this incidence?   

The authors found a clue in a 2006 study of 21,557 people with MS enrolled in the North American Committee on MS registry:  African Americans, their data suggested, are less likely to have private health insurance.  Without robust insurance plans, African American were less likely to have access to comprehensive MS care facilities.    The authors point out, in contrast, people with MS “who are cared for by a neurologist are more likely to undergo diagnostic- and treatment-related testing, receive [disease-modifying therapies], and have palliative care for symptoms; have shorter duration of illness; be less disabled; and see other specialists such as physical therapists, mental health specialists, ophthalmologists, and urologists.”   

MS is a chronic disease, and adequate care requires both life-long access to disease-modifying therapies and a commitment to adhere to a healthcare provider’s recommendations.  If a population believes that their experience with healthcare has been one of continuing discrimination and experimentation without seeking consent, open communication with a healthcare provider about the expectations and goals of disease-modifying therapies become more challenging for both provider and person with MS.   

What is the take-away of this study? 

Two points stand out from this interesting article.  First, data, not perception, drives good health care.  Without more successful efforts to recruit people of African, Latino, and Asian descent into clinical trials, we cannot better understand the course of MS in all populations, and healthcare providers will not have tools to deliver the most effective care to each individual with MS.  To deliver effective care to all populations with MS, we need to accumulate more data supporting development of evidence-based strategies that reduce the frequency and severity of acute relapses and slow or prevent further disease progression and disability.   Certainly, efforts to include more minority groups in clinical trials and studies will contribute more valuable data.  Second, both recruitment of minority populations with MS and ensuring adequate care to them may require sustained investment in programs that promote patient education, medication adherence, symptom management, and a healthy lifestyle.  

Original Article