By Spondylitis Association of America
Monday, February 26, 2018
A person’s genetic makeup, including HLA-B27, is thought to make up roughly 90% of the disease risk in ankylosing spondylitis (AS.)1 It’s not surprising then that ethnicity plays a large role in the frequency of AS throughout the world. New research now suggests that ethnicity may also play a role in disease activity and severity. A study published in the Journal of the International League of Associations for Rheumatology investigated AS severity in three different ethnic/racial groups – Blacks, Whites, and Latinos –analyzing also the association of HLA-B27 with AS in these groups.2
925 adult AS patients from the U.S. and Australia were recruited from the study investigator’s clinics, patient organizations – such as the Spondylitis Association of America, and other various rheumatology practices. Genetic and statistical analyses were conducted, and clinical and radiographic measurements and tools were used to analyze disease activity and severity in the three groups.
Though it has previously been established that Blacks experience the lowest rates of both ankylosing spondylitis (AS) and axial spondyloarthritis (axSpA) due to lower frequencies of HLA-B27, the study found that the Black AS patients enrolled had the highest levels of disease activity, functional capacity/impairment, and most radiographic severity of the three groups studied.
Disease activity is classified and measured using three separate scientific methods.
Unlike disease activity, functional impairment is classified using only one measure: the Bath Ankylosing Spondylitis Functional Index (BASFI). The BASFI uses a similar 1-10 scale, but rates a patient’s confidence in their ability to complete certain activities or tasks, such as putting on socks or standing unsupported for 10 minutes without discomfort. In this category as well, Black patients were more significantly impacted by the disease (6.25) than both Latinos (3.81) and Whites (2.78) enrolled in the study.
Radiographic severity was measured in two ways.
Despite the lower frequency of HLA-B27 and the resulting lower prevalence of AS/axSpA in the Black population, the results of this study demonstrate higher levels of disease activity, greater functional impairment, and greater radiographic severity in Black AS patients. The exact causes of this remain unknown however, and will need to be investigated in future studies.
Further Reading and Sources Used:
Visit our careers page for available positions
16360 Roscoe Blvd. Ste. 100Van Nuys, CA 91406
(800) 777-8189 U.S. only
or (818) 892-1616*Please note: This is not a Crisis Hotline. If you are in a life-threatening crisis, please dial 911 for immediate help in the US. Please follow this link for crisis intervention resources.