What is Ankylosing Spondylitis?
Ankylosing spondylitis (pronounced ank-kih-low-sing spon-dill-eye-tiss), or AS, is a form of arthritis that primarily affects the spine, although other joints can become involved. It causes inflammation of the spinal joints (vertebrae) that can lead to severe, chronic pain and discomfort. In the most advanced cases (but not in all cases), this inflammation can lead to new bone formation on the spine, causing the spine to fuse in a fixed, immobile position, sometimes creating a forward-stooped posture known as kyphosis.

AS can also cause inflammation, pain and stiffness in other areas of the body such as the shoulders, hips, ribs, heels and small joints of the hands and feet. Sometimes the eyes can become involved (known as Iritis or Uveitis), and rarely, the lungs and heart can be affected. The hallmark feature of ankylosing spondylitis is the involvement of the sacroiliac (SI) joints during the progression of the disease, which are the joints at the base of the spine, where the spine joins the pelvis.

Symptoms vary depending on the severity of the disease:
  • Intermittent back pain and discomfort in some people while others can have severe pain and stiffness
  • Acute, painful episodes("flares") followed by temporary periods of remission where symptoms subside.
                            
What causes Ankylosing Spondylitis?
Although the exact cause of AS is unknown, we do know that genetics play a key role in AS. Most individuals who have AS also have a gene that produces a "genetic marker" - in this case, a protein - called HLA-B27. This marker is found in over 95% of people in the Caucasian population with AS (the association between ankylosing spondylitis and HLA-B27 varies greatly between ethnic and racial group. It is important to note however, that you do not need to have to be HLA-B27 positive to have AS and also a lot of HLA-B27 positive people never contract AS.

Who is At Risk?
The risk factors that predispose a person to ankylosing spondylitis include:

  • Testing positive for the HLA-B27 marker
  • A family history of AS
  • Frequent gastrointestinal infections

Unlike other forms of arthritis and rheumatic diseases, general onset of AS commonly occurs in younger people, between the ages of 17-45. However, it can affect children and those who are much older. AS is more common in men, but occurs in women as well.

How is AS diagnosed?
With the use of X-rays and MRI to detect any sacroiliac involvement. Blood tests may also be done but it is not diagnostic as HLA-B27 is a perfectly normal gene found in 8% of the Caucasian population.

How is AS treated?
Currently, there is no cure for AS, but there are treatments and medications to reduce symptoms and manage pain such as the NSAIDs (nonsteroidal anti-inflammatory drugs) which are still the first line of treatment to manage pain and stiffness. When NSAIDs are not enough, the next stage of medications, (also known as second line medications), are sometimes called disease modifying anti-rheumatic drugs (DMARDS).This group of medications include: Sulfasalazine, Methotrexate and Corticosteroids The most recent and most promising medications for treating ankylosing spondylitis are the biologics, or TNF Blockers. These drugs have been shown to be highly effective in treating not only the arthritis of the joints, but also the spinal arthritis. Included in this group are Enbrel, Remicade, Humira and Simponi.


Note: Please see your physician/rheumatologist if you have any of the above symptoms.

Source: http://www.spondylitis.org/about/as.aspx