What is Ankylosing Spondylitis?

Ankylosing spondylitis (AS) is a member of a group of diseases that attack the spine called spondyloarthropathies. The disease causes arthritis of SI joints, spine & can causes inflammation of the eyes, lungs, and heart valves. It varies from intermittent episodes of back pain that occur throughout life to a severe chronic disease that attacks the spine, peripheral joints and other body organs, resulting in severe joint & back stiffness, loss of motion & deformity as life progresses.

What Are Spondyloarthropathies:

These are a group of rheumatic diseases that share common clinical genetic & radiological features:

1. Predilection of inflammatory lesions of axial skeleton (SI joints & spondylitis)

2. Enthesitis: Inflammation at bony insertion of tendons, ligaments, articular capsules.

3. Oligoarticular Peripheral joint Arthritis (Involvement of 2-5 joints).

4. Frequent involvement of eye, heart(aortitis), skin & mucous membrane.

5. Strong association with HLA B₂₇ & negative rheumatoid factor.

6. Tendency to affect mainly young adult males(except in blind loop syndrome).

What Are Different Subgroups of Spondyloarthropathies?

1. Ankylosing spondylitis
2. Psoriatic Arthritis
3. Reiter's Syndrome
4. Juveline ankylosing spondylitis
5. Arthropathies of IBD

Who Is Affected?

It commonly occurs below 40 years of age, males commonly affected. There is variations in different ethnic group and is most common in native Americans.

What Are The Causes?

It is believed that interactions between genetic factor, HLAB₂₇ and the environment factor (the bacterial infection) leads to immune response resulting in ankylosing spondylitis.

What Are The Different Joints Involved?

The joints involved are:

1. Axial Skeleton: Sacroiliac joint, spine(cervical, thoracic & lumbar)
2. Anterior central joint involving rib cage & sternum
3. Large peripheral joints: Hips, shoulder, Knees.
4. Rarely small peripheral joints

What Are Other Symptoms of AS?

Some people have eye inflammation, more severe cases may develop heart valve involvement. Other may have fever, fatigue, weight loss, anemia. At times there may be associated inflammatory bowel disease.

How It Is Diagnosed?

The diagnosis is a clinical one, combined with x-ray finding. Laboratory evaluation may reveal an elevated ESR, anaemia & positive HLA-B₂₇ assay. X-rays & bone scan may show characteristics changes.

How Is It Treated?

Early diagnosis is very important for good prognosis from this disease.

Medical therapy comprises of NSAIDs (pain killers), indomethacin being the most effective of them and sulfasalazine (which is considered to have a disease modifying role). Unresponding peripheral arthritis may require treatment with methotrexate.

Physical therapists may help by advising proper sleep & walking positions coupled with abdominal & back exercise, to maintain proper posture. Exercises to help maintain joint flexibility include aerobics & swimming. Breathing exercises are advisable as this disease is associated with decreased lung capacity.

What Is The Prognosis?

Even with optimal treatment, some people will develop a stiff or "ankylosed" spine, but they will remain functional if this fusion occurs in an upright position. Continuing care is very important as AS is a lifelong problem, and people often fail to continue treatment, in which case permanent posture & mobility loss occurs.