Lupus

Also known as: Lupus, disseminated lupus erythematosus, lupus erythematosus, SLE, LE

What is it?

Lupus (SLE) is a chronic, inflammatory autoimmune disorder that may affect many organ systems including the skin, joints, and internal organs. SLE affects women eight times more often than men and usually occurs between the ages of 10 and 50. Certain drugs may also cause SLE.

The disorder usually begins in one organ, but others may be involved as it progresses. Some ways lupus shows itself include: arthritis-like joint pain; a rash – particularly one resembling a butterfly across the nose and cheeks; increased protein in the urine; seizures; psychoses or headaches; blood clots leading to strokes and pulmonary embolisms; and inflammation of parts of the heart and lungs.

Tests
Diagnosis is made by physical observation, symptoms, x-rays and some, or all, of the following laboratory tests:

Anti-nuclear antibody test (ANA) – positive; other specific types of anti-nuclear antibodies can also be positive: anti-double stranded DNA (especially common with kidney involvement), anti-Sm (usually seen only in lupus), anti-histone (seen usually in lupus caused by drugs).
Urine analysis – shows blood, microscopic casts of kidney cells, or protein
Full blood count (FBC) – decrease in some cell types, including platelets
Rheumatoid factor (RF) – positive
Serum protein electrophoresis – increased gamma globulin proteins
Sedimentation rate (ESR) and C-reactive protein (CRP) – increased
Cryoglobulin – positive; cryoglobulins are abnormal proteins in the blood that will precipitate when the body temperature drops below normal, causing blockage of the blood vessels. The test involves collecting blood and cooling it in the laboratory, then checking for the presence of the precipitate.
Complement 3 (C-3) – decreased; C-3 is one of nine major complement proteins associated with some diseases. Decreased amounts may be associated with lupus, gram-negative septicaemia, and shock, as well as malaria.

Treatment
There is no cure for lupus; therefore, treatment is geared toward alleviating the symptoms associated with the illness.

Common Question
My doctor told me my ANA test is positive but s/he isn't sure I have lupus. How can this be?

The body’s immune system normally produces antibodies that are designed to fight off diseases and infections. In an autoimmune disease, something goes wrong with this system and the person’s body begins producing antibodies against their own tissues. Antinuclear antibodies are antibodies that go against the cell nucleus, or central controlling part of the cell. The ANA test looks at the concentration of antinuclear antibodies in a person’s blood. A positive result means that you have a higher than “normal” concentration of these antibodies.

This is just one of the tools in diagnosing lupus as well as several other autoimmune diseases, so a positive result may be related to lupus or another disease. Or, you may simply have a higher than normal concentration of these antibodies just as some people’s normal body temperature is higher or lower than 37°C. Even among people with lupus, these results can vary widely – one person can be in remission at a certain level of ANA while another can be extremely ill at the same level.

Interpreting what these results mean for you is the work of your doctor. Your doctor may need to compare your test results as well as the severity of your symptoms over a period of time in order to make a definitive diagnosis. This additional time may also allow your doctor the opportunity to eliminate other possible causes for your symptoms.

For more FAQs, see Lupus UK: commonly asked questions and answers on lupus