Ankylosing Spondylitis Causes and Risk Factors

Health Writer
Medically Reviewed

What causes ankylosing spondylitis?

We wish we had a short answer, but research to date has not pinpointed the cause of ankylosing spondylitis (AS). What we do know: clinical scientists suspect that specific genetic factors are associated with AS. The gene HLA-B27 is linked to AS in some way. Most people who have the HLA-B27 gene do not acquire AS, however, and not all people with AS have the HLA-B27 gene. HLA-B27 accounts for nearly a third of risk, and other causal and risk factors remain to be discovered.

According to the Spondylitis Association of America (SAA), the presence of specific genes, coupled with an environmental exposure such as a bacterial infection, may activate AS in certain people. Researchers have identified more than 60 genes associated with AS. Among the key genes are ERAP-1, IL-12, IL-17, and IL-23. An unproven but strongly suspected hypothesis is that AS may begin when the body’s defense mechanism in the intestines fails and bacteria enter the bloodstream, causing a change in immune response.

college students

What are the risk factors for ankylosing spondylitis?

AS risk factors include testing positive for having the HLA-B27 gene, a family history of AS, and frequent gastrointestinal infections. With regard to age of onset, AS departs from other types of arthritis and rheumatic disorders. AS onset usually occurs in people between age 17 and 45. Note the word usually. That’s because AS can affect children and older persons. Men are more likely than women to get AS.


What behaviors can have an impact on ankylosing spondylitis?

Tobacco smokers with AS have more spinal damage than nonsmokers according to the Arthritis Foundation. Failing to engage in physical activity can worsen the pain and stiffening. The Cleveland Clinic recommends supervised physical therapy and exercise over do-it-yourself versions, which may inadvertently overstress certain joints. With AS, it’s more important than ever to practice good posture and stand as straight as possible. According to the Mayo Clinic, applying heat can relieve pain and stiffness, while ice can help inflammation and swelling.

Seeking information from reputable organizations such as those in the preceding links and engaging in support groups can boost outlook and morale because, indeed, the person with AS is not alone. SSA offers a robust social network of the testimonies of AS sufferers, education and advocacy, and a resource for finding support groups. Check out the map of support groups. If you don’t live near one, contact another group and explore opportunities to network via online connections. Establishing connections with others is a great way to bolster morale and learn what works for others to relieve symptoms and optimize quality of life.