Lupus (systemic lupus erythematosus) is a chronic disease of the immune system that causes inflammation throughout the body. Normally the immune system makes proteins called antibodies that protect the body against foreign invaders like viruses, bacteria, and cancers. In lupus, the immune system malfunctions and produces antibodies that mistakenly attack healthy tissues. Lupus most commonly affects the skin, joints, kidneys, heart, brain, lungs, and blood cells. Lupus belongs to a group of disorders called autoimmune diseases, which attack various parts of the body in a similar fashion.
Main Types of Lupus
Discoid lupus is primarily limited to the skin.
Systemic lupus involves skin, joints, and internal organs.
Drug-induced lupus is triggered by certain medications. This condition completely resolves when the medication is discontinued.
Lupus occurs far more frequently in women than men and usually occurs in people between age 15 and 40.
The underlying cause of lupus is unknown, but genetics, hormones, and environmental factors are key elements. Certain genes predispose people to develop lupus by increasing their susceptibility to triggers in the environment. People with lupus often have a close relative with lupus or another autoimmune disease. Additionally, African Americans, Hispanics, and Asians are at increased risk for the disorder.
In women, the hormone estrogen is a very important causal factor. Nine times more women develop lupus than men.
Environmental factors associated with lupus include the following:
Toxic substances, such as cigarette smoke, mercury, and silica
Exposure to sunlight
Lupus is a lifelong disease characterized by periods of exacerbation (flares), alternating with mild illness or absence of symptoms (remission). Symptoms of lupus are highly variable, so some individuals experience mild symptoms while others develop serious illness.
The following are the most common signs and symptoms of lupus:
Decreased circulation in fingers and toes in response to cold (Raynaud’s phenomenon).
The symptoms associated with lupus are often difficult to distinguish from other diseases. Many patients experience mild or vague symptoms, making these cases particularly difficult to diagnosis.
When the symptoms and physical examination suggest a diagnosis of lupus, blood tests are used to measure specific types of antibodies, which are elevated in people with lupus.
Testing for Lupus
Antinuclear antibody (ANA) test measures the level of antibodies produced by the immune system and is elevated in autoimmune diseases such as lupus.
Antiphospholipid antibody test measures another type of antibody that is often elevated in people with lupus.
Red blood cell count is often low (anemia).
Kidney function is evaluated with blood and urine tests.
Kidney biopsy may be required to determine the extent of any kidney disease. In this procedure a sample of kidney tissue is removed and examined under a microscope.
Skin biopsy is used to confirm the diagnosis of discoid lupus.
Lupus is a life-long condition and there is no cure. However, there are effective treatments to control symptoms, and most people with lupus live a normal active life. Rarely, lupus involves multiple organs, causing life-threatening illness that requires aggressive treatment.
Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that decreases inflammation.
Prednisone is a steroid - a potent drug that reduces inflammation and suppresses the immune system.
Immune suppressing agents, such as azathioprine and cyclophosphamide, are powerful drugs that block activities in the immune system.
Antimalarial drugs, like hydroxychloroquine, decrease antibody production.
There are no known methods to prevent the occurrence of lupus. However, in individuals with the disease, certain measures help decrease the incidence of lupus flares. In some cases, the skin rashes are prevented by avoidance of excessive exposure to sunlight and the use of sunscreen. Healthy lifestyle habits - proper nutrition, avoidance of stress, and not smoking - help prevent severe illness.
Systemic Lupus Erythematosus (Lupus). American College of Rheumatology website. https://www.rheumatology.org/practice/clinical/patients/diseases_and_conditions/lupus.asp. Accessed December 4, 2014.
Handout on Health: Systemic Lupus Erythematosus. National Institute of Arthritis and Musculoskeletal and Skin Diseases website. http://www.niams.nih.gov/Health_Info/Lupus/default.asp. Accessed December 4, 2014.
Lupus Primer. The Johns Hopkins Lupus Center website. http://www.hopkinslupus.org/lupus-info/. Accessed December 5, 2014.
Lupus. Mayo Clinic website. http://www.mayoclinic.org/diseases-conditions/lupus/basics/definition/con-20019676. Accessed December 4, 2014.
Lupus. Cleveland Clinic website. http://my.clevelandclinic.org/health/diseases_conditions/hic_systemic_lupus_erythematosus. Accessed December 4, 2014.
Tina is a Life Science Writer for a number of online publications, including Innerbody.com. Her expertise is in conveying complex scientific topics to diverse audiences. Tina earned her PhD in Biochemistry from the University of California, San Francisco and her BS degree in Cell Biology from U.C. Davis. In her spare time, she enjoys drawing science-related cartoons.