Science closes in on this crippling disease

New findings may help diagnose, treat, and even cure some forms of arthritis. Researchers are zeroing in on ways to diagnose the two most common forms of arthritis before serious joint damage is done, in order to more effectively treat both forms of the disease and, possibly, to cure one of them.

To diagnose osteoarthritis early, some scientists are looking for biomarkers, chemicals in blood or joint fluid that might reflect cartilage injury. Others are scanning for changes in cartilage that precede the breakdown or loss of cartilage that occurs in joints damaged by ostseoarthritis. Researchers have known that healthy cartilage holds water tightly. Damaged cartilage allows water to move through it more easily, ultimately leading to fragmentation and loss of cartilage. At Penn State, researchers have developed an MRI technique to scan for changes in the water content of cartilage, allowing doctors to pinpoint trouble spots in joints at a very early stage.

"My guess is that the eventual gold standard will be a combination of these two approaches: using biomarkers to test for biochemical damage, then MRI to examine the structure of an individual joint," says Penn State researcher Timothy Mosher, MD.

On the treatment front, scientists are studying ways to harvest cartilage cells, grow them in a petri dish, and then inject them into joints to repair damage, says Bonnie Bermas, MD, director of the Women's Musculoskaletal Center at Brigham and Women's Hospital in Boston.

Rheumatoid Arthritis: Cause and Cure?

Researchers are also developing a new technique to diagnose One of the most serious forms of arthritis, rheumatoid arthritis (RA). In RA, antibodies from the immune system attack joints, causing Inflammation and damage. Researchers are using a new molecular biology technique called microarray to search for the targets (antigens) of the immune attack on the joint and aid in early diagnosis.

After adding a small sample of a patient's blood (which contains antibodies) to a microarray, the researchers are checking to see which antigens the antibodies target. In healthy people, antibodies will ignore most antigens, but in those with RA, they'll attach to antigens found in joints, explains Paul J. Utz, MD, researcher for the Atlanta-based Arthritis Foundation (AF) and assistant professor of medicine at Stanford University.

In addition to helping doctors diagnose RA, microarray technology may also enable them to better treat it. They may be able to design individualized therapies for patients, therapies that keep the immune system from attacking harmless antigens in joints but leave it free to fight infections, Dr. Utz explains.

An outright cure for RA may even be on the horizon if another promising avenue of research pans out. Harvard researchers recently discovered what may be a cause of the disease. They found that in RA, the immune system inappropriately turns on and attacks complex carbohydrates called glycosaminoglycans (GAGs), which are naturally found in joint cartilage.

"There are several possible scenarios for this," says John Klippel, MD, medical director of the AF. "It could be that GAGs in a joint have somehow been changed by a bacterium or virus, or there could be a genetic defect in the immune system of these people. Whatever it is in the normal immune system that tells it GAGs are okay may be missing in people with FLA."

If the culprit is a bacterium or virus, then drugs or an immunization to block the immune system's response to GAGs might be the answer, says Dr. Klippel. A genetic defect, however, would be more complicated to correct.