Ethnic disparities in the epidemiological and clinical characteristics of multiple sclerosis

BACKGROUND: Multiple Sclerosis (MS) is a neuroinflammatory disorder which affects 2.8 million people world-wide. A growing body of evidence shows ethnic disparities in MS. This review aims to evaluate differences, based upon ethnic background, in the incidence, prevalence, disease course, and efficacy of disease-modifying therapies (DMTs) among people with MS (PwMS). METHOD: Ethnicities were classified as White, Black, Hispanic, Asian, and Middle Eastern and North African (MENA). A literature search was conducted using the PubMed search engine to identify articles on MS and ethnicity that were published in the English language between 01/01/2005 and 31/05/2022. RESULTS: 101 studies met all inclusion criteria. Although the incidence and prevalence of MS varied among ethnicities, findings were inconsistent and depended on the continent of the study. Ethnicity may have an impact on the disease course. PwMS from Black, Hispanic, and MENA, but not Asian ethnicities, appeared to accumulate physical disability at a faster rate than those from White ethnicity. Although there was a lack of studies evaluating the relative safety and efficacy of DMTs among various ethnicities, interferon-beta was found to be less efficacious in PwMS from Black ethnicity. CONCLUSIONS: Further studies, with more uniform definitions of ethnicity are required to comprehensively understand ethnic disparities in MS, in particular to identify underlying causes, to facilitate the delivery of personalised medical care and avoid inequity.