Systemic lupus erythematosus, often called SLE or lupus, is a chronic inflammatory disease that can affect the skin, joints, kidneys, lungs, nervous system, and other organs of the body. It is sometimes labeled the “great imitator” because its wide variety of symptoms can often be confused with other disorders. Usually, patients with SLE experience skin rashes and arthritis as well as fatigue and fever, and the disease can be fatal. However, improvements in therapy have significantly increased these patients’ quality of life and their life expectancy.
SLE typically develops in people in their 20s and 30s, and it develops 10 times more often in women than in men. It is more common in certain ethnic groups, particularly among African Americans and Asians, who also tend to be more severely affected.
The immune system normally protects the body by producing antibodies that attack foreign germs and cancers. With SLE, the immune system misfires. Instead of producing protective antibodies, the autoimmune disorder begins manufacturing “auto-antibodies” that attack the patient’s own tissues. This leads to inflammation and blood vessel abnormalities (vasculitis). These antibodies then end up in the immune system of cells in organs where they cause tissue damage. Why this inflammatory reaction begins is not known, but according to patient–fact sheet writers Ellen Ginzler, MD, and Jean Tayar, MD, “It is probably the result of a combination of inherited tendencies and environmental factors, such as viruses, the ultraviolet rays in sunlight, Silica dust, and allergies to medications.”
Diagnosis of SLE is difficult due to the gradual development of the symptoms. Suspected cases must be confirmed by a series of blood tests. More specific tests, such as the anti–double-strand DNA and anti-Smith antibodies, confirm the diagnosis of SLE. Levels of certain complement proteins (a part of the immune system) in the blood are also measured to help diagnose and track the disease. Physicians frequently use the 1997 update of the 1982 Revised Criteria for Classification of Systemic Lupus Erythematosus to aid them in considering whether a patient with symptoms may have SLE. “Although this table was originally designed for clinical research studies, it can be helpful when considering an individual patient as well,” say Drs. Ginzler and Tayar.
There is no cure for SLE, and its management can be a challenge. However, in the past several years, treatment has improved considerably, and recent medical developments have proven effective. Treatment decisions are based on symptoms and the severity of those symptoms. Patients with muscle or joint pain, fatigue, skin abnormalities (such as rashes), and other responses that are not life threatening can be treated conservatively. Those with serious and life-threatening problems—such as kidney inflammation, lung or heart involvement, and central nervous system symptoms—need more aggressive therapy. Treatment depends on an individual assessment of risks and benefits. Most immunosuppressive medications, for instance, may cause significant side effects, such as increased risk of infections, nausea, vomiting, hair loss, diarrhea, high blood pressure, and osteoporosis. Rheumatologists may reduce or discontinue a medication after the disease goes into remission for a period of time.