Medical Edge Newspaper Column

New Drug Promising for Type Of Inflammatory Arthritis

July 25, 2008
Dear Mayo Clinic:
I've been diagnosed with ankylosing spondylitis. Is there a recommended treatment?

Answer:
Medications are available to treat the joint pain and stiffness that accompany ankylosing spondylitis. But one new class of drugs looks particularly promising for both relieving symptoms and treating the disease's underlying cause.

Ankylosing spondylitis is a chronic form of inflammatory arthritis, a disease of the immune system. It prompts your immune system to attack the joints of the body. While almost any joint can be affected, the disease especially affects the joints between the vertebrae of the spine and the joints between the spine and pelvis (sacroiliac). As a result, the joints are damaged and become swollen and painful.

Over time, the spine can become very stiff. For example, when people who have ankylosing spondylitis get out of bed in the morning, they may experience unusual spine stiffness that lasts for an hour or more. This morning back pain is very different from those first few minutes of stiffness most people feel before the "kinks are worked out."

Other symptoms can include a low-grade fever, weight loss, and swelling in other joints, including the shoulders, hips, and knees, and joints in the hands and feet. The disease may also cause inflammation and pain where the tendons and ligaments attach to bones and in some organs, especially the heart, lung and eyes.

Unlike most forms of inflammatory arthritis, ankylosing spondylitis affects men more than women. In addition, over 90 percent of people who have the disease also have the gene HLAB27. That gene appears to increase the susceptibility to ankylosing spondylitis. Not everybody who has the gene gets the disease, but most people who have the disease have the gene. Although researchers don't yet understand the process, the condition seems to result from the interaction of HLAB27 and the immune system.

The prognosis for people who have ankylosing spondylitis has improved markedly over the past several decades. We have much better treatments today. Traditionally, we relied mainly on nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and other drugs related to aspirin to reduce inflammation and pain. Those drugs can help relieve some symptoms but don't treat the underlying problem.

Corticosteroids, such as prednisone, have also been used to suppress inflammation and slow joint damage in severe cases of ankylosing spondylitis. But, we don't like to use them often because of potential side effects, including fluid retention, increased blood pressure, diabetes, thinning of the bones and weight gain. And, like NSAIDs including aspirin, corticosteroids don't treat the underlying cause of the disease.

Another type of medication, disease-modifying anti-rheumatic drugs, can be used to treat inflamed joints of the limbs and other inflamed tissues. These medications can help limit the amount of joint damage that occurs as a result of the disease, but they often don't relieve spine stiffness.

Recently, a group of drugs called tumor necrosis factor alpha blockers have been approved for the treatment of ankylosing spondylitis. These medications appear to combat one of the principle underlying immunological problems by blocking a protein that works as an inflammatory agent in the body. At this time, these medications seem to hold the most promise for controlling symptoms and preventing damage to the joints.

In addition to medications, physical therapy can be an important component of treatment. Therapy may help relieve pain, maintain joint flexibility, preserve good posture and increase your strength. I advise you to talk to your physician about a treatment program that combines medication and physical therapy.

— Eric Matteson, M.D., Rheumatology, Mayo Clinic, Rochester, Minn.