Systemic Lupus Erythematosus
Systemic lupus erythematosus (SLE) is an autoimmune, multisystem disease with a wide variety of symptoms. The primary immunological defect is the production of antibodies against one’s own self. These molecules cause tissue injury principally in the skin, joints, kidneys, nervous system, heart, and the lungs and surrounding linings. Systemic Lupus Erythematosus affects 1 in 2,000 individuals in the general outpatient population. Women of childbear-ing age are most commonly affected. A genetic predisposition to Systemic Lupus Erythematosus is likely since first-degree relatives have a much higher frequency of disease. Environmental factors, including ultraviolet light, emotional stress, and certain drugs, may also play a role by bringing on the disease or worsening it. Thus, Systemic Lupus Erythematosus is a complex disease of many potential causes, including genetic and environmental factors, which results in an immune system that fights against normal tissues.
The symptoms of Systemic Lupus Erythematosus vary, but usually include nonspecific features such as fatigue, fever, and weight loss. Systemic Lupus Erythematosus potentially can affect almost every body part. Because of this variability and the fact that other diseases may resemble Systemic Lupus Erythematosus, diagnostic criteria have been developed. Although the list of criteria is a handy checklist, it is only a guide and is used primarily for research studies. In a research study, a patient must have 4 of the 11 criteria to meet the diagnosis of Systemic Lupus Erythematosus. However, in practice, patients are often treated as symptoms arise and may not have 4 criteria even though treatment is warranted.
The skin is most commonly involved. The characteristic malar or “butterfly rash” is a red and swollen rash extending over the bony part of the nose and across the cheeks, often associated with sun exposure and getting sick from the sun. Painful joints are the most common initial symptoms of Systemic Lupus Erythematosus. Arthritis may involve the hands, wrists, and knees on both sides of the body. This pattern also occurs in rheumatoid arthritis (RA), but unlike RA, permanent deformity does not develop. The kidney is one of the most important organs affected by Systemic Lupus Erythematosus, and kidney failure is the most common cause of death. Inflammatory reactions within the kidney lead to deposition of proteins that can cause a variety of problems including leakage of blood and protein into the urine. Nervous system involvement is also common and may involve the brain, nerves, and automatic functions such as blood pressure and pulse rate. Systemic Lupus Erythematosus affects the heart by causing swelling and irritation of the heart. This may produce a scratching sound when listening with a stethoscope. More than one third of Systemic Lupus Erythematosus patients have some form of lung disease during their lifetime, mostly involving the lining around the lung. The eye, the gastrointestinal tract, and liver may also be involved.
Since Systemic Lupus Erythematosus causes various changes in the blood itself, the complete blood count (CBC) is important in evaluating the disease. Up to 80% of patients will have anemia, due to many potential causes such as iron deficiency or destruction of blood cells by the immune system. This may result in not only decreased red blood cells but also decreased white blood cells and platelets. A low platelet count can cause nosebleeds and bleeding in the skin and gums. At times, this may be the only manifestation of Systemic Lupus Erythematosus.
Blood tests look for proteins and cells directed against otherwise normal proteins in the blood. Some of these tests include a positive antinuclear antibodies (ANA), antibodies to double-stranded DNA, and anti-Sm (Smith) antigen. A positive ANA may be found with autoimmunity but does not automatically diagnose Systemic Lupus Erythematosus, since there are many conditions that may cause a false-positive ANA. Complement proteins, which are involved in inflammation, can also be measured and are often greatly decreased, especially if there is active kidney involvement. Overall, these tests or measurements of antibodies are important for baseline evaluation, but treatment of Systemic Lupus Erythematosus should not be based on serological test results alone. More importantly, treatment should be based on the history and physical exam of each individual.
Due to the various drug treatments available, treatment should be based on the patient’s symptoms and their severity. Education is extremely important. The patient, along with his or her support network, should be provided information about Systemic Lupus Erythematosus, support groups and organizations, and strategies to maintain his or her quality of life.
Drugs commonly used in the treatment of Systemic Lupus Erythematosus include nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, antimalarials, and several immunosup-pressants.
NSAIDs are frequently used for musculoskeletal pain, inflammation, and headaches. Patients should be monitored for common side effects including gastrointestinal bleeding, liver or kidney damage, and high blood pressure.
Corticosteroids are often used for the immediate relief of life-threatening symptoms. Topical creams and joint injections should be used sparingly. Long-term use of corticosteroids should be avoided due to many potential side effects.
Antimalarial medications are commonly used for fatigue, skin, and musculoskeletal symptoms. Antimalarials are generally well tolerated and help avoid the need for corticosteroids. The most significant risk involves eye toxicity and a thorough eye examination by an ophthalmologist is required every 6 months.
Cyclophosphamide, a strong immunosuppressant, is used for severe organ-system disease, particularly for kidney damage due to Systemic Lupus Erythematosus (lupus nephritis). Side effects include bone marrow suppression, bleeding from the bladder, and severe hair loss (alopecia). Regular laboratory monitoring is required. Other immunosuppressive medications, such as azathioprine and methotrexate, are often used as an alternative agent for the treatment of nephritis or to avoid corticosteroids for nonkidney symptoms.
Alternative therapies and experimental drugs under investigation include stem cell research and biologic therapies. However, more studies of long-term effects and effectiveness will be needed before these treatments can be used in the management of Systemic Lupus Erythematosus.
See Also: Autoimmune disorders
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