Research on Arthritis.

Research on types of arthritis

Ankylosing spondylitis and Reiter's syndrome

Ankylosing spondylitis and Reiter's syndrome are related to the HLA-B27 gene and affect the spine and legs. Researchers are trying to discover how the gene interacts with infections to trigger these diseases.

Some studies indicate that a few people with HLA-B27 may develop ankylosing spondylitis after a bowel infection. Signs of bowel inflammation and spondylitis have been reported to improve after taking the antibiotic sulfasalazine.

Some of the proteins related to HLAB27 are identical to proteins in the bacterium Klebsiella, which can produce bowel infections leading to Reiter's syndrome.

Some people with the AIDS virus have also developed Reiter's syndrome, leading researchers to study related mechanisms in both diseases.

Fibrositis or fibromyalgia

Fibrositis or fibromyalgia refers to a condition that involves pain, stiffness and fatigue in muscles, ligaments and tendons. Researchers are trying to improve methods to diagnose and treat the disease.

Sleep disorders, chemical reactions in the brain or nervous system, immune responses, muscle disease, personality and stress have been linked as possible factors in causing or triggering fibrositis.

Fibrositis-like symptoms can appear in some other types of arthritis. For example, people with rheumatoid arthritis may also experience sleep disturbances and tender points. It is not clear how these symptoms are related.

Gout

Gout occurs when excess uric acid crystals collect in the joints, especially the big toe, and cause severe pain. Researchers are trying to eliminate some of the causes of gout.

Low levels of the enzyme HPRT result in too much uric acid build-up. Scientists have located the gene that passes on an inherited lack of this enzyme.

For over 100 years, scientists have known that lead poisoning causes gout. Now, they are trying to find out if exposure to small amounts of lead from jobs or hobbies, such as stained glass, can also cause gout.

Plans are under way for a federal health study to see how many people, who have been told they have gout and are taking anti-gout drugs, actually have the disease or just have elevated levels of uric acid in their blood.

Juvenile rheumatoid arthritis

Juvenile rheumatoid arthritis may cause children's joints to become inflamed, deformed, and sometimes damaged. Scientists are trying to understand what goes wrong with the body's immune system, how the disease affects growth, and what treatments used for adults are safe and effective for growing children.

HLA-type antigens have been associated with certain types of juvenile arthritis. Findings may help explain if some children are more likely to develop the disease.

Oral gold (auranofin), a drug used for adults with rheumatoid arthritis, can be safely used in children and teenagers with juvenile rheumatoid arthritis.

Lyme disease

Lyme disease results from infection by spiral-shaped bacteria carried by a tick that can affect joints and many different parts of the body. Researchers are tracking the spread of Lyme disease and studying it as a possible model for explaining what happens in rheumatoid arthritis.

Lyme disease has been reported in over 33 states since it was first described in 1977. Blood samples from over half the farmers tested in one midwestern state showed signs of infection from the spirochete or spiral-shaped bacteria transmitted by bites from infected ticks. Scientists are now wondering why just some people who are bitten go on to develop Lyme disease or the chronic arthritis that accompanies it. One study showed that people with HLA-DR3 or DR4 genes were more likely to develop chronic arthritis.

Similarities between changes in joints affected by Lyme disease and rheumatoid arthritis have encouraged researchers to look at what happens in Lyme disease as a possible clue to what happens in rheumatoid arthritis.

Osteoarthritis

Osteoarthritis involves a gradual breakdown in joint tissue, usually in the hands, knees and hips. Researchers are looking for factors that cause changes in cartilage and bone and why such changes occur more rapidly in some people.

One byproduct of the rapid breakdown of cartilage is a substance called keratan sulfate. Researchers are working on a blood test for this substance that may help detect osteoarthritis in earlier stages.

Two studies have shown that people who are very overweight, especially women, have a greater chance of developing osteoarthritis of the knees. Very heavy black women appear to have an even higher risk. Early studies also suggest that twisting injuries to the knee and repeated knee bending may also increase risk.

Osteoporosis

Osteoporosis is a condition that causes bones in the wrist, spine and hips to lose strength and break or fracture. Researchers are looking at risk factors that may help prevent the disorder and ways to provide better diagnosis and treatment.

Bone cells have recently been found to contain receptors for estrogen. Estrogen used for the first six years after menopause has been shown to protect against fracture.

Calcium and exercise are important for building stronger bones but their exact role in osteoporosis is hotly debated.

Psoriatic arthritis

Psoriatic arthritis develops from the skin condition psoriasis and can cause swelling in fingers, fingernails, toes and sometimes the spine. Researchers are looking for causes and better treatments for this type of arthritis.

One gene has been linked to psoriatic arthritis and scientists are looking for others. Researchers are now studying whether people with psoriasis, but not arthritis, also have this gene.

Drugs that affect the immune system have been shown to be effective in psoriasis, leading researchers to look closer at the role of the immune system in psoriatic arthritis.

Rheumatoid arthritis

Rheumatoid arthritis affects many joints, especially the hands and feet, as well as other parts of the body. Researchers are looking at the interaction of genes and infection in causing the disease as well as seeking better treatments.

Most people with rheumatoid arthritis carry a gene called HLA-DR4 or a similar one, HLA-DR1. Scientists suspect other genes are related to rheumatoid arthritis. For instance, one study showed a large number of people with rheumatoid arthritis in a family group had HLA-DR4 and a second gene.

About 80 percent of those with rheumatoid arthritis have an autoantibody called rheumatoid factor. People with certain chronic infections, such as tuberculosis, also have this factor in their blood. This suggests that an infection is involved in rheumatoid arthritis.

Two experimental drugs, one of which controls the immune system, are being tested in rheumatoid arthritis. Gamma interferon, which the body produces, has shown promise in small numbers of people. Therafactin, a drug made from a complex sugar molecule, has shown in early studies that it reduces inflammation.

Scleroderma

Scleroderma and mixed connective tissue disease are related conditions that affect the connective tissues, such as the skin and blood vessels. Researchers are looking for better ways to diagnose and treat these diseases.

Autoantibodies discovered in the blood have helped doctors separate the diagnoses of three very similar conditions scleroderma, mixed connective tissue disease and polymyositis. A new technique using ultrasound is also helping measure skin thickness in scleroderma.

A drug used to treat severe high blood pressure, called captopril, has also been used to dramatically reduce blood pressure and protect the kidneys in people with scleroderma, who developed a serious form of kidney disease.

Lupus

Systemic lupus erythematosus most often affects young women and involves a disorder in the body's immune system that can affect many parts of the body, including joints. Scientists are finding different genetic patterns and autoantibodies for lupus and its complications.

High levels of interferon have been found in people with lupus. Scientists are looking at interferon to see whether this substance, which the body produces naturally, contributes to lupus.

People with lupus make many autoantibodies against normal parts of the body. One autoantibody, anti-native DNA, occurs in about 80 percent of those with untreated lupus.

Credits

Some of this material may also be available in an Arthritis Foundation brochure. Contact the Washington/Alaska Chapter Helpline: (800) 542-0295. If dialing from outside of WA and AK, contact the National Helpline: (800) 283-7800.

Adapted from the pamphlets originally prepared for the Arthritis Foundation by Irving Fox, MD, Frederic McDuffie, MD, and Robert Rich, MD. This material is protected by copyright.

Disclaimer

This resource has been provided by the University of Washington Department of Orthopaedics and Sports Medicine as general information only. This information may not apply to a specific patient. Additional information may be found at http://www.orthop.washington.edu or by contacting the UW Department of Orthopaedics and Sports Medicine.