Dr. Theo on Arthritis Continued
ANKYLOSING SPONDYLITIS
If you wake up in the morning with lower back pain and stiffness,
if you've had the low back pain for longer than three months, and if it gets
better with exercise but is not improved with rest. you may have ankylosing
spondylitis (AS).
Causing fused spinal vertebrae, AS is most commonly seen in young
men. It sometimes goes untreated in earlier stages because it can easily be
confused with mechanical back pain, the kind you get from lifting a heavy
object. With AS, the tendons and ligaments that move the back become inflamed.
The vertebrae respond to the problem by producing more bone. The body's
response is well intentioned, but making extra bone can cause the vertebrae to
grow into each other and fuse together. Eventually, the spine can wind up
looking like a bamboo pole. It gets so stiff that the natural inward curvature
of the low back and the natural extension of the neck are lost, making AS
sufferers appear bent over. They don't really have trouble holding up their heads-their
neck vertebrae are fused in that position. If you have ever seen an elderly
person walking bent over as though he were looking at his shoes, you have
probably witnessed the late stages of AS.
AS inflammation usually begins in the lower back, and always
involves the sacroiliac joints (the joints where the lower spine meets the
pelvis). In later stages the middle and upper back and neck are afflicted. The
disease can spread down into the buttocks and thighs, or up into the chest,
where it can make deep breaths difficult. The inflammation may also strike the
joints of the shoulder, knees, or ankles. It can also affect the eyes about 30
percent of patients with AS will develop anterior uveitis (inflammation of the
iris) at some point. In fact, in some 20 percent of AS cases, the first signs
of arthritis appear in the knees, hips, heels, or eyes.
Young men between 16 and 35 years of age are the favorite targets
of AS, which afflicts approximately I in 1,000 people under the age of 40.
Three times as many males as females are diagnosed with the disease, but this
may be because females tend to have much milder symptoms and may never be
diagnosed. It also appears in children (mostly boys), who account for roughly 5
percent of the cases. It is rarely seen in African Americans.
Scientists have found what may prove to be a genetic basis for AS.
The disease is found almost exclusively in those who have the HLA-B27 gene, a
gene involved in fighting infection. But don't worry if you carry HLA-B27-less
than 5 percent of those with the gene eventually develop the disease. It's not
enough simply to have the genetic tendency the gene has to be "switched
on" somehow. (If one identical twin develops AS, it appears in the other
twin only 60 percent of the time.) Studies currently under way are looking into
the possibility that a certain type of infection triggers AS.
Early diagnosis and proper treatment of AS can reduce or prevent
deformity. The treatment regimens are designed to reduce pain and prevent
deformities, while strengthening the back and neck. Nonsteroidal
anti-inflammatory drugs (NSAIDs) are used to reduce pain and inflammation but
do not prevent progression of the disease. Exercise and posture improvement
help to increase strength and flexibility. The new biologic agents infliximab
and etanercept show great promise in the treatment of AS. Not only do they help
decrease pain and increase flexibility in patients with AS, they can also slow
or even stop progression of the disease. In July 2003 etanercept (Enbrel) was
approved by the FDA for treatment of AS. Glucosamine and chondroitin are often
used by AS sufferers, but mainly in an effort to decrease their reliance on
NSAIDs. Some patients report that the supplements glucosamine and chondroitin
sulfate help, but no formal studies on these supplements or ASU have been done
yet.