Ankylosing Spondylitis

What is Ankylosing Spondylitis?

Ankylosing Spondylitis is a common condition mainly causing inflammation of the spine and pelvis (together known as the axial skeleton). This leads to pain and may cause permanent damage of joints. Ankylosing Spondylitis often affects a person’s mobility, function and quality of life. Where the spine and pelvis join, known as the sacro-iliac joint, often becomes inflamed leading to the term ‘sacroiliitis.’

Ankylosing Spondylitis is part of a group of similar diseases called the ‘spondylarthritides (SpA),’ which also includes psoriatic SpA, reactive SpA, SpA associated idiopathic bowel disease and undifferentiated SpA. Often, more than one of these conditions may occur in the same person.

How common is Ankylosing Spondylitis?

Ankylosing Spondylitis generally affects young people, with 80% of people diagnosed with Ankylosing Spondylitis being under the age of 30 years. It affects males up to 5 times as much as females. In Europe, 0.1 –1.4% of the population is affected. Studies have shown that people with direct family members (such as a brother or sister) are also at a 6 to 16 times increased risk of developing Ankylosing Spondylitis.

What causes Ankylosing Spondylitis?

We do not know the exact cause of Ankylosing Spondylitis. We do know that a certain gene called HLA-B27 is found in almost all people with Ankylosing Spondylitis (up to 95% of people in fact). HLA-B27 is a gene involved in the immune system and works by helping immune cells recognise dangerous organisms that are not part of a person’s body. However, only 1.2-1.3% of people with this HLA-B27 gene go on to suffer from Ankylosing Spondylitis, meaning other genes and/or environmental factors (such as bacteria or viruses) are involved too.

What are the symptoms of Ankylosing Spondylitis?

Common signs and symptoms of Ankylosing Spondylitis are:

• Back pain and/or back stiffness
• Worse in the morning or after rest
• More than 30 minutes
• Improves with activity
• Joint pains of arms, hands, legs or feet (usually one or more joints affected)
• Hip and shoulder pain (in 20%)
• Inflammation of a part of the eye, the uvea (often only one eye, but this can alternate)
• Pain at heel or Achilles tendon
• Alternating buttock pain
• Rarely, problems with the heart (such as aortic valve regurgitation) or lungs (such as fibrosis)
• Symptoms from other SpA, such as psoriasis or colitis

It is important to note that not all these symptoms will occur in everyone.

How is Ankylosing Spondylitis diagnosed?

Different criteria may be used to diagnose Ankylosing Spondylitis and requires the opinion of a specialist doctor. The most common criteria is the Modified New York Criteria 1984:

1. Lower back pain for at least 3 months which is improved by exercise and not relieved by rest
2. Restricted movement of the lumbar spine (the lower part of the back) both bending forwards and sideways
3. Restricted movement of chest expansion compared to normal values expected of the person’s age and sex.
4. X-rays demonstrating minor changes (grade 2 changes) or worse on both sides of the sacroiliac joint, or moderate changes (grade 3 changes) or more on one side.

If point 4 occurs with any of points 1, 2 or 3, then Ankylosing Spondylitis is definite.

More recently, a new set of criteria not requiring x-rays has been suggested (1):

1. Morning stiffness of >30 minutes
2. Improvement of back pain with exercise but not with rest
3. Awakening with back pain during the second half of the night only
4. Alternating buttock pain

If two out of the four pf the points are fulfilled, this is suggestive of Ankylosing Spondylitis.

What other names do people use for ankylosing spondylitis?

• Ankylosing Spondylitis - Ankylosing spondylitis
• Bechterew Disease
• Marie-Struempell Disease
• Rheumatoid Spondylitis
• Spondylarthritis Ankylopoietica
• Spondylitis ankylopoietica
• Spondylitis, Ankylosing
• Spondyloarthritis Ankylopoietica

What happens if the doctor suspects you have Ankylosing Spondylitis?

X-rays are often used to help detect and diagnose people who are suspected of having Ankylosing Spondylitis. This is because people who have the disease for a while will show changes in their spine and pelvis. A series of x-rays are also useful to monitor any changes that may occur over a period of time.

MRI may also be used. This is very good at detecting early changes and any inflammation which may be occurring at the time. However, this is quite an expensive procedure and may not be used in everyone.

Blood samples may be taken to detect if you have the HLA-B27 gene and to see if there are any changes in your blood as a result of Ankylosing Spondylitis. The type of things that are measured in your blood include C-reactive protein (CRP), which is present in the blood if any inflammation occurs (remember, this may include other things apart from Ankylosing Spondylitis such as any infection), and red blood cells, which may be reduced.

How do you treat Ankylosing Spondylitis?

Unfortunately, there is no cure at the moment for Ankylosing Spondylitis. The type of treatment is usually dependent on the individual person and this can include how severe the disease is or what the person would want.

Treatment without medication involves regular exercises, physiotherapy, spa therapy, education and self help groups.

Medication for Ankylosing Spondylitis:

Non steroidal anti-inflammatory drugs (NSAIDS)

This type of drug includes aspirin or ibuprofen and have been shown to be extremely effective in controlling pain and stiffness. They may also slow down the progression of the disease. However, it must be remembered that NSAIDS may have side-effects. This can include bleeding or the drug may affect you if you have kidney problems or ulcers.

Tumour necrosis factor blockers (TNF blockers)

TNF is used in the immune system as a signalling molecule. TNF blockers are a recent, new set of drugs. There are three main ones – infliximab, adalimumab and etanercept. Recent studies have shown improvements in pain and function of people who have been treated with these type of drugs.

However, this medication is extremely expensive and their side-effects include increased chances of infection, worsening of heart failure in people with the disease already and possibly increased risk of cancer. It is for this reason that strict criteria have been released to offer guidance to doctors on when to use these type of drugs. NICE have published guidelines in 2008 (2).

Disease Modifying anti-rheumatic drugs (DMARDS)

These type of durgs include sulfasalazine and methotrexoate. However, studies have shown no strong evidence in the effectiveness of these drugs, although they may help affected joints of the hand, feet, leg and arm in people with Ankylosing Spondylitis.

Steroids

Occasionally, steroids may be injected into the joint

What are the complications of Ankylosing Spondylitis?

People with Ankylosing Spondylitis are more likely to suffer from osteoporosis (a condition leading to weakening of the bones) and fractures. Therefore drugs used to treat osteoporosis, such as calcium supplements or bisphosphonates are used.

People may also suffer from heart and blood vessel disease. Therefore, drugs such as statins may be used to reduce this risk.

Key points

• Ankylosing Spondylitis is an inflammatory condition of the body, associated with the HLA-B27 gene
• It commonly affects the spine and pelvis, but can affect other joints in the body
• It is diagnosed through the New York Criteria 1984
• Treatment involves the combinations of medicines and exercise

References

1. Rudwaleit M, Metter A, Listing J, Sieper J, Braun J. Inflammatory back pain in ankylosing spondylitis: a reassessment of the clinical history for application as classification and diagnostic criteria. Arthritis Rheum. 2006 Feb;54(2):569-78.
2. http://guidance.nice.org.uk/TA143/Guidance/pdf/English. [cited 2009 14/7]