Rapid disease course in African Americans with multiple sclerosis

Abstract

The 6-tiered MSSS grading system is a powerful tool for comparing rate of disease progression in subpopulations of interest. MSSS-based analysis demonstrates that African ancestry is a risk factor for a more rapidly disabling disease course.

Disability and progression in Afro-descendant patients with multiple sclerosis

“…Together, they covered a population of 52,470 patients, 4,068 AD (7.8%) and 48,402 CA (92.2%). Eleven studies analyzed the three clinical phenotypes of the disease 15,16,17,20,21,22,23,24,25,26,27 , two only evaluated the RR/SP forms 2,28 and one, just the PP form…”

“…The remaining articles were fully analyzed and the STROBE checklist for cohort studies was applied. Studies that had the same source of patients, like the New York State Multiple Sclerosis Consortium (NYSMSC) 16,20 and North American Research Committee on Multiple Sclerosis (NARCOMS) 17,21 were only counted once, using the study with the higher number of patients, thus avoiding a duplicate count. Fourteen articles fulfilled the inclusion criteria (Figure).…”

“…The clinical and demographic characteristics analyzed in twelve studies were: gender, age, race, MS history (age at onset, age at diagnosis, functional system affected), disability status and treatment 2,15,16,17,20,21,22,23,26,27,28,29 . Six studies also evaluated the progression status 2,15,26,27,28,29 .…”

“…Six studies also evaluated the progression status 2,15,26,27,28,29 . The ancestry was defined through self-report questionnaires 2,15,16,17,20,21,26,27 , by the presence of one black skin relative up to three previous generations 28,29 , or by the parents' background 22 . One study did not describe how ethnicity was determined 23 .…”

“…Different endpoints were adopted: a) the mean or median EDSS at a certain time 16,23,26,28 , b) time to reach disability markers by EDSS 0 and 2 16 15,26,27,28,29 , e) analysis of benign and malignant courses 2,28 . Besides the EDSS, another three scales were applied for assessing the disability: the Multiple Sclerosis Severity Score (MSSS) 20 , Patient Determined Disease Steps (PDDS) 17,21 and ADL Long Form Scale 24,25 (Table 1 and Table 2). Progression was considered as the increase of one point in the EDSS scale, not attributed to relapse, maintained for six months or more, without improvement, or for a progressive worsening of symptoms in six articles 2,15,26,27,28,29 .…”