La ankylosing spondylitis, also called ankylosing spondylitis, is a rheumatic disease that mainly affects the spine and lower back. It begins in young people, usually in men of 15 to 40 years old.

like any rheumatism, it results in pain and loss of flexibility in the joints. The most characteristic sign of ankylosing spondylitis (AS) is pain in the lower spine, sacroiliac joints (where the column attaches to the pelvis).

However, the disease can also affect other joints, such as the ankles or knees. It can also be accompanied by inflammation of the eye or digestive symptoms.

It’s about a chronic and progressive disease, which leads to progressive stiffening (stiffness) of the joints, hence the term “ankylosing”. Over time, the vertebrae may even weld together, causing severe stiffness in the spine. However, with early treatment it is possible to effectively control the symptoms and limit theankylose. Today, severe forms of spondylitis with ankylosis are increasingly rare and specialists even tend to no longer use the term “ankylosing”.

Prevalence

La ankylosing spondylitis is a relatively rare disease that mainly affects young men, otherwise healthy. The exact prevalence of the disease is not known, but most studies estimate that it affects 1 in 500 to 1 in 100 people.¹. The disease is very common in some Native American populations².

According to the Canadian Arthritis Society, between 150 and 000 Canadians have ankylosing spondylitis.

The disease is about 3 times more common in men than in women.

Causes

The exact cause of ankylosing spondylitis is not known. It’s about a inflammatory disease, that is to say, it induces chronic inflammation of the joints. The disease is probably linked to a set of genetic and environmental factors:

• Genetic factors : Ankylosing spondylitis mostly occurs in people who have a particular gene called HLA-B27. This is why it is more common in certain populations or in certain families. However, this gene is not the cause of the disease: it is only a predisposing factor. The HLA-B27 gene is present in 6% of the population and in 93% of people with ankylosing spondylitis. Thus, only 5% to 6% of people with this gene develop ankylosing spondylitis.³. In addition, other genes are most certainly involved in the disease;
• External factors : Researchers believe that environmental factors play a role in triggering the disease in genetically predisposed people. These could in particular be bacteria, responsible for digestive (Klebsiella bacteria) or genital infections, which would cause changes in the immune system and trigger the disease.⁴. Joint symptoms of spondyloarthritis often appear within weeks of a genital or digestive infection⁵.

Complications

Although symptoms may appear periodically, the disease tends to progress continuously as the inflammation persists and continues to worsen the skin. joints and cartilage (the discs) of the back. Over time, a fusion of the vertebrae can form in some patients. However, the course of the disease is very slow, over several years.