August 19, 2011
Dear Mayo Clinic:
My 43-year-old daughter has been diagnosed with lupus. Is there any new information about lupus? What is the latest research?
Lupus is a complex disease. The exact cause isn't known, but a variety of factors appear to influence the development of lupus. In the last several decades, research has focused on pinpointing genes that predispose people to lupus, investigating molecules that play a role in the disease, and identifying new therapies to treat lupus.
Lupus is an autoimmune disease, meaning the immune system attacks the body's own tissues and organs, causing inflammation and damage. Lupus can affect any system in the body. The body systems most commonly involved include the skin, joints, lungs, kidneys and blood. In some people, lupus may be a minor disease with only a skin rash. In others, lupus may be severe, causing nervous system complications, anemia or life-threatening kidney disease.
The risk of heart disease is increased in lupus patients. Traditional risk factors like smoking, diabetes mellitus, high blood pressure, high cholesterol and menopause do not fully account for the heightened risk, and several lupus-related factors play a role. These include persistent low-grade inflammation, the presence of abnormal proteins that increase the risk of clotting, a decreased number and function of the cells lining the blood vessels, and kidney disease. Exercise, smoking cessation, a healthy diet, and control of disease activity all may help reduce the risk of heart disease in people with lupus. The use of statin therapy (Lipitor, Crestor, others) also may be effective for some individuals.
The cause of lupus is likely a combination of genetic and environmental factors — such as smoking, exposure to sunlight or use of certain medications. Lupus is much more common in women than men and is often triggered by pregnancy, suggesting that hormones have an important effect on the disease's development.
Genes that predispose people to lupus are important for immune system function. However, researchers have learned that having those genes isn't the end of the story. It appears that genetic makeup can put a person at high risk for lupus, but the disease requires additional triggers like medication, hormones, infection or other environmental factors.
Research into the genetic factors in lupus has led to an investigation of key molecules associated with the disease. One protein in particular, interferon alpha, has been investigated most in the last few decades. Interferon alpha can help produce auto-antibodies, which are connected to the development of lupus. Currently, research is examining the effect of blocking interferon alpha activity in people who have lupus, and the preliminary clinical trials are encouraging.
In terms of therapy for the disease, several new drugs have been recently tested for treating lupus. In March 2011, the Food and Drug Administration (FDA) approved belimumab for treatment of lupus. Belimumab blocks a protein called BLyS, which is important for survival of immune cells that produce auto-antibodies.
Although it's the first drug in 50 years to be approved for lupus treatment, the effects of belimumab are modest and the drug has not been tested in people with severe disease. In addition, the clinical research trials did not show any important benefits in African-Americans, a population that has an increased risk of lupus. Therefore, more studies are needed before we can find the exact place for belimumab in lupus therapy.
Lupus researchers have also studied the effectiveness of the medication rituximab. This drug can decrease the number of B lymphocytes, a type of white blood cell that produces auto-antibodies. Although many people with resistant lupus have benefitted from rituximab, two large clinical trials surprisingly failed to show any benefit of this drug for lupus treatment. The reasons behind these findings aren't clear, and additional studies are necessary to identify people who may benefit from rituximab.
Several drugs already in use for treatment of rheumatoid arthritis, including tocilizumab and abatacept, are being studied in clinical trials for lupus treatment. New therapies, such as atacicept, have undergone preliminary clinical testing and show promising results, as well.
Although no cure is currently available for lupus, these advances in research offer hope for the future. At this time, to most effectively manage her condition, your daughter should work with a specialized care team familiar with lupus. Treating lupus can be challenging, but with focused, specialized medical care, many people with this disease lead fulfilling lives.
— Vaidehi Chowdhary, M.D., Rheumatology, Mayo Clinic, Rochester, Minn.