Lupus and SLE
Lupus is a chronic, autoimmune disorder. In lupus, the immune system attacks healthy cells and tissues by mistake. This can damage joints, skin, blood vessels and organs.
There are many kinds of lupus. The most common type, systemic lupus erythematosus (SLE), affects many parts of the body. Discoid lupus causes a rash that doesn’t go away. Subacute cutaneous lupus (SCL) causes sores after being in the sun. Another type called drug-induced lupus (DIL) can be caused by medication. Neonatal lupus, which is rare, affects newborns.
Anyone can get lupus, but women are most at risk. It is a common autoimmune condition in African, Hispanic, Asian and Native American women affecting up to 1 in 1,000 of the female population.
The cause of lupus is not known. However, a combination of genetics (heredity), environment, and hormones is involved. There is no cure for lupus, but medicines and lifestyle changes can help control it. (LinkOut to an excellent review article on SLE, published in the Orphanet Journal of Rare Diseases, Open Access, accessed 28/07/2010 – I really do recommend this!)
Lupus has many symptoms. Common ones are:
- joint pain or swelling
- muscle pain
- fever with no known cause
- red rashes, often on the face, which is called the “butterfly rash”
Lupus is characterized by abnormalities in many laboratory test results, but there is no single test to diagnose lupus (see article Blood Tests for Diagnosing Lupus, posted 21/04/2010). The serial evaluation of an individual’s tests along with the physicians’ observations and the patient’s history determine the diagnosis of lupus, its course, and the treatment regimen.
Lupus erythematosus is an autoimmune disease that may manifest as a systemic disease or in cutaneous forms. Systemic lupus erythematosus (SLE), is the most common and serious variant of the disease. Many different organs can be affected by the disease, including joints, skin, kidney, blood cells, heart, and lungs.
SLE, or lupus for short, affects women nine times more often than men. The disease usually occurs between the ages of 20-40 years. There is an increased incidence of lupus in persons of African and Asian descent. The cause of lupus is not fully understood. It is thought to involve both an inherited component and a trigger that may be related to environmental factors and/or to hormones. Certain drugs may also cause SLE.
Lupus may co-exist with other autoimmune disorders, such as Sjögren’s syndrome, Hashimoto’s thyroiditis, and the antiphospholipid syndrome (APS). Diagnosis is made by evaluation of patient symptoms and examination findings.
The following autoantibody assays and laboratory tests may be useful in the diagnosis of lupus erythematosus and SLE: antinuclear antibodies (ANA) test is positive in almost all SLE patients; SS-A antibodies (Ro) and SS-B antibodies (La) may also be positive; anti-Sm antibodies, the so called “Smith antibodies”, are specific to lupus, but they are only seen in 10-30% of cases; antibodies to double-stranded DNA (dsDNA) are frequently present, and the anti-dsDNA level can fluctuate with disease activity.
Further lab tests may be: urine analysis, full blood count (FBC), serum protein electrophoresis, sedimentation rate (ESR), C-reactive protein (CRP), complement 3 (C-3).
Want to read more on lupus and SLE? – You will find many citations about Lupus, SLE, and autoimmune diagnostics in lupus and SLE at the end of the article Blood Tests for the Diagnosis of Lupus, posted on ORGENTEC Autoimmunity Blog, 21/04/2010.
Some Internet resources, all accessed 28/07/2010:
- Manson JJ, Rahman A. Systemic lupus erythematosus. Orphanet J Rare Dis. 2006 Mar 27;1:6. Review. – doi:10.1186/1750-1172-1-6 – open source, free full text
- What is Lupus? What is SLE? – provided by Lupus Foundation of America
- London Lupus Centre: What is Lupus? Lupus symptoms, lupus diagnosis, lupus treatment, lupus research
- Lupus Foundation of America: Understanding lupus – What causes lupus? What are the symptoms of lupus? What kind of doctors treat lupus?
- The Hopkins Lupus Centre: Understanding the signs, symptoms and diagnosis of lupus, causes and co-occurring conditions
- Lupus Foundation of Minnesota – Lupus facts: What causes lupus? What are the symptoms of lupus? Who gets lupus? Is there a cur for lupus?
- MedlinePlus article on systemic lupus erythematosus, SLE
- article on Lab Tests Online – Systemic Lupus Erythematosus: Overview, Tests, Treatment