Ankylosing Spondylitis, Rheumatologic Perspective

Ankylosing spondylitis (AS) is a type of arthritis that involves the spine and the sacroiliac (SI) joints (joints between the lowest end of the spine, called the sacrum and the pelvis). The affected joints and ligaments become swollen and painful, leading to stiffness in the back. As the disease progresses, the vertebrae may fuse together and the spine becomes rigid and inflexible, making the joints immovable. Ankylosing spondylitis can also affect other joints, tendons, and ligaments. 
 
Ankylosing spondylitis affects approximately 0.1-0.2% of the population. It primarily affects young males. Females often experience a less severe form of the disease. The usual age of onset is from the late teens to age 40 years. Approximately 10-20% of all persons with ankylosing spondylitis have onset of symptoms when younger than 16 years (juvenile-onset ankylosing spondylitis).

A combination of genetic and environmental factors is believed to cause ankylosing spondylitis, but the exact cause is unknown. Studies have shown that most people with ankylosing spondylitis have the gene for HLA-B27. A person with the gene for HLA-B27 is not guaranteed to develop ankylosing spondylitis; however, having the gene increases the likelihood for a person to develop ankylosing spondylitis. Infection of the intestines with certain bacteria (Klebsiella) may trigger a reaction in persons with the gene for HLA-B27, causing the development of ankylosing spondylitis.

Symptoms vary from person to person. Typical symptoms of ankylosing spondylitis include the following:

• Gradual onset of back pain and stiffness



• Early-morning pain and stiffness that is relieved with exercise or a warm shower



• Fatigue



• Fever



• Loss of appetite



• Complete loss of spine mobility (in persons with advanced ankylosing spondylitis)

No laboratory tests can be used specifically to diagnose ankylosing spondylitis. The diagnosis is aided by the symptoms of ankylosing spondylitis, family history of ankylosing spondylitis, x-ray film findings, and a test for the gene for HLA-B27.

Persons with ankylosing spondylitis may have an elevated erythrocyte sedimentation rate (ESR), which is the rate at which red blood cells settle to the bottom of a tube in 1 hour. A raised ESR is an indication of inflammation in the body that results from many types of inflammatory diseases and does not necessarily indicate ankylosing spondylitis.

Blood examination may reveal anemia (decreased levels of hemoglobin), which is a complication that can result from ankylosing spondylitis.

The presence of the gene for HLA-B27 is not diagnostic for ankylosing spondylitis. However, the absence of the gene for HLA-B27 means that the presence of ankylosing spondylitis is less likely.

Spinal x-ray films of persons with ankylosing spondylitis reveal characteristic changes in the sacroiliac joints and the spine.

MRI or CT scan may reveal evidence of early changes in the sacroiliac joints and the spine that are not seen on the x-ray film. However, because of their high cost, MRI and CT scans are not part of the routine examinations of persons with suspected ankylosing spondylitis.

The aims of treatment of ankylosing spondylitis are to reduce pain and stiffness, to prevent deformities, and to help maintain normal activities.

Treatment of ankylosing spondylitis includes exercise and physical therapy to help improve posture and spinal mobility and medical treatment to reduce inflammation and pain.

The following steps help alleviate pain and stiffness in people with ankylosing spondylitis:

• Keep the spine straight.



• Sleep on a hard mattress.



• Try to sleep in a prone position (on the abdomen) without a pillow.



• Try to sleep in a supine position (on the back) with a thin pillow.



• Keep the legs straight when sleeping.



• Do not sleep in a curled-up position.



• When walking or sitting, keep the spine as straight as possible.



• Use chairs and work surfaces specially designed to support the spine.

Regular exercise is an essential part of the treatment of ankylosing spondylitis. Exercises that strengthen the back and neck help maintain correct posture. Swimming is an excellent exercise because it promotes flexibility of the spine and movement of the shoulder and hip joints. A hot shower before exercise relieves some joint pain and stiffness and makes exercising easier and less painful. Exercise should be started slowly and performed when pain is minimized.

Although medications do not cure ankylosing spondylitis, they relieve pain and stiffness, allowing the person to exercise, to maintain correct posture, and to continue daily activities. The medications used in the treatment of ankylosing spondylitis include the following:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most commonly used medications. NSAIDs do not cure ankylosing spondylitis, but they reduce the pain and stiffness of ankylosing spondylitis. Commonly used NSAIDs include diclofenac (Cataflam, Voltaren), ibuprofen (Advil, Motrin), ketoprofen (Orudis), naproxen (Aleve, Naprosyn), piroxicam (Feldene), etodolac (Lodine), indomethacin, oxaprozin (Daypro), nabumetone (Relafen), and meloxicam (Mobic). People with ankylosing spondylitis respond differently to each of the many NSAIDs available. An NSAID that works for one person may not work for another person. Be patient and actively participate in deciding which NSAID provides maximum relief. Side effects of NSAIDs include heartburn, nausea, abdominal pain, diarrhea, and bleeding ulcers. To decrease the risk of heartburn and ulcers, NSAIDs should be taken with food. Sometimes, taking antacids or other medicines may be necessary to prevent heartburn and ulceration caused by NSAIDs.



• Sulfasalazine (Azulfidine) has been shown to reduce the pain and stiffness of ankylosing spondylitis, especially of peripheral joints (eg, hips, shoulders). Side effects include rash, nausea, and diarrhea. A rare but serious side effect is a severe reduction in the number of white blood cells, which predisposes the individual to life-threatening infections.



• The new medications that block tumor necrosis factor (TNF)-alpha (a substance that plays a role in the inflammatory process of ankylosing spondylitis) are useful in the treatment of ankylosing spondylitis. Examples of TNF-alpha blockers include etanercept (Enbrel) and infliximab (Remicade). Etanercept is administered as an injection either once or twice per week. Infliximab is administered as an intravenous infusion every 2 weeks for 3 doses, then every 8 weeks to maintain the effect.



• Other medications such as methotrexate (Rheumatrex), azathioprine (Imuran), cyclophosphamide (Cytoxan), and cyclosporine (Sandimmune, Neoral) may be helpful in the treatment of ankylosing spondylitis, especially when peripheral joints are involved. They are prescribed only if NSAIDs are not effective in controlling the symptoms of ankylosing spondylitis.



• Oral corticosteroids, such as prednisone, are occasionally helpful in controlling symptoms; however, they should be used for only short-term management.

For more information, see Understanding Ankylosing Spondylitis Medications.

Surgery is occasionally indicated in the treatment of AS. It may be performed to repair damaged peripheral joints or to correct spinal deformities.

Persons with ankylosing spondylitis may need total hip replacement and, occasionally, total shoulder replacement. These procedures may reduce pain and improve function when the hip and shoulder joints become severely damaged.

Rarely, surgery may be performed to correct spinal deformities. Only surgeons who specialize in spine surgery and have experience with the procedure should perform this surgery.

Rehabilitation therapies are important in the treatment of ankylosing spondylitis. Proper sleep and walking postures, together with abdominal and back exercises, help maintain correct posture. Exercises help maintain joint mobility.

Physical therapy is not believed to prevent the progression of ankylosing spondylitis, but it may minimize symptoms in some persons.

• The course of ankylosing spondylitis may change over time, with periods of relapses and remissions.



• The outlook of most persons with ankylosing spondylitis is generally good. They can expect to lead normal lives. Few people with ankylosing spondylitis become severely disabled.

• Long-term therapy with NSAIDs is usually required.



• Indicators of poor outlook include involvement of a peripheral joint (eg, hip, shoulder), young age of onset, elevated ESR, and poor response to NSAIDs.

A long-term illness, such as ankylosing spondylitis, can bring physical and emotional challenges. People often find benefit from sharing questions and concerns with others who have the same illness. The following Web sites provide support to people with ankylosing spondylitis and their families and friends:

• Spondylitis Association of America Sponsored Support Groups



• Reiter's Information & Support Group Inc.

Spondylitis Association of America
PO Box 5872
Sherman Oaks, CA 91413
(800) 777-8189, (818) 981-1616
info@spondylitis.org

The North American Spine Society
22 Calendar Court, 2nd Floor  
LaGrange, IL USA 60525
(877)-Spine-Dr, (847) 698-1630
info@spine.org

Arthritis Foundation
PO Box 7669
Atlanta, GA 30357-0669
(800) 283-7800

American College of Rheumatology
1800 Century Place, Suite 250
Atlanta, GA 30345-4300
(404) 633 3777

National Institute of Arthritis and Musculoskeletal and Skin Diseases
Bldg 31, Room 4C02
31 Center Dr - MSC 2350
Bethesda, MD 20892-2350
(301) 496-8190

Ankylosing Spondylitis International Federation
6 Falcarragh Road, Gaeltacht Park
Whitehall, Dublin 9, Ireland
(+353-1) 83 76 614
asai@oceanfree.net

|Web Links|

The Assessment in Ankylosing Spondylitis (ASAS) International Working Group

MedlinePlus, Ankylosing Spondylitis

MayoClinic, Ankylosing spondylitis

Media file 1: Pelvic x-ray film of a person with ankylosing spondylitis showing involvement of the sacroiliac joints.

Media type:  X-RAY

rheumatologic perspective of ankylosing spondylitis, AS, arthritis, sacroiliac joint, intervertebral joint, fused vertebra, bamboo spine, rigid spine, back stiffness, early-morning stiffness, loss of spine mobility, HLA-B27, nonsteroidal anti-inflammatory drugs, NSAIDs, sulfasalazine, TNF-alpha blockers

Author: Lawrence H Brent, MD, Chair, Program Director, Associate Professor, Department of Medicine, Division of Rheumatology, Albert Einstein Medical Center, Thomas Jefferson University.

Editors: Kristine M Lohr, MD, Associate Chief, Program Director, Professor, Department of Internal Medicine, Division of Rheumatology, University of Tennessee School of Medicine; Mary L Windle, Pharm D, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Pharmacy Editor, .com, Inc; Rick Kulkarni, MD, Assistant Professor of Medicine, David Geffen UCLA School of Medicine; Director of Informatics, Department of Emergency Medicine, UCLA/Olive View-UCLA Medical Center.