This is a disease awareness website produced by UCB and is intended for a UK and Ireland audience.

Axial Spondyloarthritis and Ankylosing Spondylitis

Axial spondyloarthritis (axSpA)

What is Axial Spondyloarthritis and Ankylosing Spondylitis?

Axial spondyloarthritis (axSpA) is an umbrella term for non-radiographic axSpA (nr-axSpA) and radiographic axSpA, also known as Ankylosing Spondylitis (AS). nr-axSpA and AS are closely related rheumatic conditions, both forms of inflammatory arthritis.

Inflammation is a normal part of the immune system, where blood flow is increased and specialised cells are sent to specific areas. While inflammation is usually an important part of the body’s defense against infection, it can become over-active, leading to conditions such as axSpA.

axSpA causes several parts of the lower spine to become inflamed, including the bones in the spine (vertebrae), spinal joints (sacroiliac joints) and other areas of the body. Over time, this can damage the spine and lead to the growth of new bone, which in some cases can cause parts of the spine to join up (fuse) and lose flexibility. This is known as ankylosis.

For people with AS, changes to the sacroiliac joints or spine can be seen on x-ray scans. However, for people with nr-axSpA these changes are not visible on x-ray, but inflammation may be visible on MRI (magnetic resonance imaging).

axSpA/AS symptoms

axSpA symptoms can vary from person to person and usually develop over several months or years. axSpA can develop at any time but usually begins to develop in teenagers and young adults. The symptoms can come and go and may even change over time.

Almost all cases of axial spondyloarthritis are characterised by acute, painful episodes (flares), which are followed by periods when symptoms improve (remission).

The main symptoms of axial spondyloarthritis/AS are:

What causes axSpA/AS?

What causes axSpA?

It's not yet known what causes axSpA/AS, but there seems to be a link with a particular gene known as human leukocyte antigen B27 (HLA-B27).

Research has shown more than 9 out of 10 people with axSpA/AS carry the HLA-B27 gene. However, having the gene doesn’t necessarily mean you’ll develop axSpA.

axSpA/AS may be triggered by one or more environmental factors, although it’s not known what these are.

Can axSpA/AS be inherited?

AS can run in families and the HLA-B27 gene can be passed on (inherited) from another family member. People with the HLA-B27 gene with a close family member with the disease, such as a parent or a sibling (brother or sister), are much more likely to develop the condition compared to someone who does not have a relative with the condition.

If you have AS and the HLA-B27 gene, there is a 50% chance that you may pass on the gene to any children you have, but this does not mean that they will necessarily develop AS. On average the child of someone with AS has only a 7% chance of developing the condition. If the child has inherited the HLA-B27 gene this risk doubles to about 13%.

Axial Spondyloarthritis Podcasts

AxSpa Podcasts

Axial Spondyloarthritis Podcasts

Listen to rheumatology experts answer questions that are commonly asked by patients who have been diagnosed with Axial Spondyloarthritis.

Read more

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Images used are not of real patients.
IE-DA-2300074. September 2023