Clinical characteristics of African Americans vs Caucasian Americans with multiple sclerosis.
BACKGROUND
African American (AA) individuals are thought to develop multiple sclerosis (MS) less frequently than Caucasian American (CA) individuals.


OBJECTIVE
To compare the clinical characteristics of AA and CA patients with MS.


METHODS
The clinical features of MS were compared in a large retrospective cohort of AA (n = 375) and CA (n = 427) subjects.


RESULTS
The proportion of women to men was similar in AA and CA subjects (81% [AA] vs 77% [CA]; p = 0.122). There were no differences in the proportions of subjects with relapsing-remitting, secondary progressive, primary progressive, and progressive relapsing MS. The median time to diagnosis was 1 year after symptom onset in AA subjects and 2 years after symptom onset in CA subjects (p = 0.0013). The age at onset was approximately 2.5 years later in AA than CA subjects (33.7 vs 31.1 years; p = 0.0001). AA subjects presented with multisite signs and symptoms at disease onset more often than CA subjects (p = 0.018). Clinical involvement restricted to the optic nerves and spinal cord (opticospinal MS) occurred in 16.8% of AA patients compared with 7.9% of CA patients (p < 0.001). Transverse myelitis also occurred more frequently in AA subjects (28 vs 18%; p = 0.001). Survival analysis revealed that AA subjects were at higher risk for development of ambulatory disability than CA subjects. After adjusting for baseline variations and differences in therapeutic interventions, AAs were at 1.67-fold greater risk for requiring a cane to ambulate than CA patients (p < 0.001). There was a trend suggesting that AAs were also at greater risk for development of wheelchair dependency (p = 0.099). Adjusted Cox proportional hazard models showed that this effect was in part attributable to the older age at onset in AAs (p < 0.001).


CONCLUSIONS
Compared with multiple sclerosis (MS) in Caucasian Americans, African American patients with MS have a greater likelihood of developing opticospinal MS and transverse myelitis and have a more aggressive disease course.
Cree
B A C
BA
Multiple Sclerosis Center, Department of Neurology, University of California San Francisco, 350 Parnassus Ave., Suite 908, San Francisco, CA 94117, USA. bcree@itsa.ucsf.edu
Khan
O
O
Bourdette
D
D
Goodin
D S
DS
Cohen
J A
JA
Marrie
R A
RA
Glidden
D
D
Weinstock-Guttman
B
B
Reich
D
D
Patterson
N
N
Haines
J L
JL
Pericak-Vance
M
M
DeLoa
C
C
Oksenberg
J R
JR
Hauser
S L
SL
D000328:Adult; D001741:Black or African American; D017668:Age of Onset; D002183:Canes / Q000706:statistics & numerical data; D015331:Cohort Studies; D005260:Female; D020233:Gait Disorders, Neurologic / Q000208:ethnology / Q000209:etiology / Q000628:therapy; D006297:Health Services Accessibility / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000150:complications / Q000208:ethnology* / Q000628:therapy; D009188:Myelitis, Transverse / Q000208:ethnology / Q000209:etiology; D009901:Optic Nerve Diseases / Q000208:ethnology / Q000209:etiology; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013116:Spinal Cord / Q000503:physiopathology; D016019:Survival Analysis; D014481:United States / Q000453:epidemiology; D014910:Wheelchairs / Q000706:statistics & numerical data; D044465:White People