Ankylosing Spondylitis (AS) is a chronic inflammatory disease that primarily affects the spine, but can also impact other joints and organs. It causes inflammation in the joints between the vertebrae of the spine, which can lead to the fusion of the spine, resulting in stiffness and immobility. The onset of AS typically occurs in young adulthood, and it is more common in men. The condition can also cause inflammation in other areas of the body such as the eyes, lungs, and heart. It is a type of inflammatory arthritis and part of the spondyloarthritis family.
Ankylosing Spondylitis (AS) symptoms can vary widely from person to person, and may not appear until the disease has progressed. Common symptoms include:
- Low back pain and stiffness that is worse in the morning or after sitting or standing for a long period of time
- Pain and stiffness in the neck, chest, hips, and heels
- Fatigue and weakness
- Loss of flexibility and mobility
- Inflammation in other areas of the body such as the eyes, lungs, and heart
The diagnosis of AS is often difficult, as it can mimic other conditions and may not present with obvious symptoms. A combination of clinical examination, imaging and laboratory tests may be used to make a diagnosis.
The following are some of the diagnostic methods used:
- Physical examination
- X-rays and MRI of the spine
- Blood tests to check for the presence of the HLA-B27 gene or other markers of inflammation
- Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)
A diagnosis of AS is made when a patient has symptoms consistent with the disease, a positive HLA-B27 test and imaging that shows characteristic changes in the spine. It’s important to note that not all patients with HLA-B27 gene will have AS and not all patients with AS will have HLA-B27 gene.
Causes of Ankylosing Spondylitis
The exact cause of Ankylosing Spondylitis (AS) is not fully understood, but several factors are believed to play a role. These include:
- Genetics: The HLA-B27 gene is found in about 90% of people with AS, however, not everyone with this gene will develop the disease.
- Environmental factors: Researchers believe that certain environmental factors, such as infection with certain bacteria, may trigger the development of AS in people who are genetically predisposed to the disease.
- Immune system dysfunction: AS is believed to be caused by an abnormal response of the immune system, in which the body’s immune system mistakenly attacks its own healthy cells and tissues.
There are several risk factors that are associated with an increased risk of developing Ankylosing Spondylitis (AS). These include:
- Family history: People who have a family member with AS are at a higher risk of developing the disease.
- Male gender: AS is more common in men than in women.
- Young age at onset: AS typically begins in young adulthood, usually in the late teenage years or early twenties.
- Smoking and alcohol use: People who smoke or consume alcohol excessively have a higher risk of developing AS.
- Previous injury or infection in the spine: People who have had a previous injury or infection in the spine may have an increased risk of developing AS.