Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Genetic and Clinical Correlates in African Americans with Ankylosing Spondylitis.

Assassi4,  Shervin, Dang3,  Julie T., Ward2,  Michael M., Taurog6,  Joel D., Weisman1,  Michael H., Reveille5,  John D.

Cedars-Sinai Medical Center, Los Angeles, CA
NIH, NIAMS, IRP, Bethesda, MD
Univ of Texas Health Science Center at Houston
Univ of Texas Health Science Center at Houston, Houston, TX
Univ Texas Health Sci Ctr, Houston, TX
U-Texas SW Med Ctr, Dallas, TX

Background:

There are few studies investigating disease characteristics of ankylosing spondylitis (AS) in African Americans (AA) because of the low prevalence of AS in this population. Furthermore, there are no previous studies, comparing disease severity between AA and white patients with AS.

The goal of this study was to compare clinical parameters in AA patients with AS to white patients and to examine associations of HLA-B, DRB1 and DQB1 alleles with AS in African Americans.

Method:

Clinical data of 50 AA AS patients were derived from a cohort of 342 unrelated patients with AS. HLA class I and II alleles ascertained by DNA typing was performed on the AA AS patients as well as on 243 AA unaffected controls.

Results:

AA AS patients had higher ESR, CRP, BASDAI, BASFI, and BASRI scores than white patients (Table). The difference in ESR, BASFI and BASRI remained significant despite correcting for disease duration, HLA-B27 status, gender, educational level and use of biologics. Despite higher disease burden, AA AS patients were less likely to be using biologic agents. This was especially pronounced in AA men with AS.

HLA-B27 negative African Americans with AS were older at disease onset, and had less frequently anterior uveitis compared to HLA-B27 positive AA patients.

HLA-B27 was present in 60% of AA patients, compared with 2% of AA controls. HLA-B*4001 (B60) was the only other HLA-B allele significantly increased among patients. Marginally significant increases were also seen in HLA-DRB1*1302 and DQB1*0501.

 AA-AS patients N=50White-AS patients N=292P-valueAA Controls N=263P-valueOR
Education, college degree (%)27.861.5<0.001NANANA
BASDAI(0–10)4.853.480.009NANANA
BASFI(0–100)50.9431.20.006NANANA
BASRI (1.5–16)9.266.56<0.001NANANA
CRP (mg/dl)1.750.78<0.001NANANA
ESR (mm/hr)32.814.5<0.001NANANA
Biologic use (%)2350.70.001NANANA
HLA-B27 positivity (%)6284<0.00122.6×10-471
B*4001 (%)8NANA10.00810
DRB1*1302 (%)27NANA110.0063
DQB1*0501 (%)34NANA230.0032.8

Conclusions:

These data suggest that AA AS patients have more severe disease than whites as well as a lower frequency of HLA-B27. Also, the association with HLA-B*4001 (B60) is seen in yet another ethnic group, in addition to whites and Asians.

To cite this abstract, please use the following information:
Assassi, Shervin, Dang, Julie T., Ward, Michael M., Taurog, Joel D., Weisman, Michael H., Reveille, John D.; Genetic and Clinical Correlates in African Americans with Ankylosing Spondylitis. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :2185
DOI: 10.1002/art.29949

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