DEFINITION
Lupus is a disorder of the autoimmune
disease. In autoimmune diseases, the body harms its own
healthy cells and tissues. This leads to inflammation mage to
various body tissues. Lupus can affect many parts of the body,
including the joints, skin, kidneys, heart, lungs, blood
vessels, and brain. Lupus is characterized by periods of
illness, called flares, and periods of wellness (remission).
Although lupus is used as a broad term, several kinds of
lupus exist.
Systemic lupus erythematosus is the
most common form of the disease. The symptoms of SLE may be
mild or serious. 
Discoid lupus erythematosus refers to a skin disorder in which a red,
raised rash appears on the face, scalp, or elsewhere. The
raised areas may become thick and scaly and may cause
scarring. The rash may last for days or years and may recur. A
small percentage of persons with discoid lupus have or develop
SLE.
Drug-induced lupus refers to a form
of lupus caused by specific medications. Symptoms are similar
to those of SLE and typically resolve when the drug is
stopped.
Neonatal lupus is a rare form of
lupus affecting newborn babies of women with SLE or certain
other immune-system disorders. At birth, the babies have a
skin rash, liver abnormalities, or low blood counts, which
resolve entirely over several months. However, babies with
neonatal lupus may have a serious heart defect. Physicians can
now identify most at-risk mothers, allowing for prompt
treatment of the infant at or before birth. Neonatal lupus is
very rare, and most infants of mothers with SLE are entirely
healthy.
At present, no cure for lupus exists.
However, lupus can be very successfully treated with
appropriate drugs, and most persons with the disease can lead
active, healthy lives.
Anyone can get lupus; however, more women than men have
the disease.
In the United States, lupus is 3 times more
common in black women than in black women and is also more
common in women of Hispanic/Latino, Asian, and Native American
descent. Persons who are black or Hispanic/Latino tend to
develop lupus at a younger age and have more symptoms at
diagnosis. They also tend to have a more severe form of the
disease than black patients do. In addition, lupus can run in
families, but the risk that a child or a brother or sister of
a patient will also have lupus is still quite low.
It
is difficult to estimate how many persons in the United States
have the disease because its symptoms vary widely and its
onset is often hard to pinpoint.
Lupus is a complex disease, the cause of which is unknown. In addition, some autoantibodies join with substances from the body's own cells or tissues to form molecules called immune complexes. A buildup of these immune complexes in the body also contributes to inflammation and tissue injury in persons with lupus. Researchers do not yet understand all the factors that cause inflammation and tissue damage in lupus.
Each person's experience with
lupus is different, though patterns exist that permit accurate
diagnosis. Symptoms can range from mild to severe and may come
and go over time.
Common symptoms of lupus include
painful or swollen joints, muscle pain, unexplained fever,
skin rashes, and extreme fatigue. A
characteristic skin rash may appear across the nose and
cheeks-the so-called butterfly or malar rash. Other rashes may
occur elsewhere on the face and ears, upper arms, shoulders,
chest, and hands.
Other symptoms of lupus include
chest pain, unusual hair loss, sensitivity to the sun, anemia,
and pale or purple fingers or toes from cold and stress
(Raynaud's phenomenon). Some persons also experience
headaches, dizziness, depression, or seizures. New symptoms
may continue to appear years after the initial diagnosis, and
different symptoms can occur at different times.
The
following systems in the body also can be affected by lupus.
Kidneys: Inflammation of the kidneys
can impair their ability to get rid of waste products and
other toxins from the body effectively. Usually no pain is
associated with kidney involvement, though some persons may
notice that their ankles swell. Most often the only indication
of kidney disease is an abnormal urine or blood test.
Lungs: Some persons with lupus develop pleuritis.
Persons with lupus also may get pneumonia.
Central nervous system : In some persons, lupus affects
the brain or central nervous system. This can cause headaches,
dizziness, memory disturbances, vision problems, stroke, or
changes in behavior.
Blood vessels: Blood vessels may become inflamed, affecting the
way blood circulates through the body. The inflammation may be
mild or severe.
Blood: Persons with lupus may develop anemia,
leukopenia, or thrombocytopenia. Some persons with lupus may
have abnormalities that cause an increased risk for blood
clots.
Heart:
In some persons with lupus, myocarditis, endocarditis, or
pericarditis can occur, causing chest pains or other symptoms.
Lupus can also increase the risk of
atherosclerosis
Despite the symptoms persons with lupus
can maintain a high quality of life overall. One key to
managing lupus is understanding the disease and its impact.
The diagnosis
of lupus can be difficult. It may take months or even years
for physicians to piece together the symptoms to diagnose this
complex disease accurately.
No single test can
determine whether a person has lupus, but several laboratory
tests may aid in the diagnosis. Most persons with
lupus test positive for ANA. However, there are a
number of other causes of positive ANA results, including
infections and other rheumatic or immune diseases-occasionally
they even are found in healthy adults. The ANA test simply
provides another clue for the physician to consider in making
a diagnosis.
In addition, blood tests for individual
types of autoantibodies exist that are more specific to
persons with lupus, though not all persons with lupus test
positive for these, and not all persons with these antibodies
have lupus. These antibodies include anti-DNA,
anti-Sm, anti-RNP, anti-Ro (SSA), and anti-La (SSB).
These antibody tests may help in the diagnosis of lupus.
Some tests are used less frequently but may be helpful
if the cause of a person's symptoms remains unclear. A
biopsy of the skin or kidneys may be indicated if those body
systems are affected. A test for syphilis or the
anticardiolipin antibody may also be useful. Positive test
results do not mean that a person has syphilis; however, the
presence of this antibody may increase the risk of blood
clotting and can increase the risk of miscarriages in pregnant
women with lupus. Again, all these tests merely serve as tools
in making a diagnosis.
Other laboratory tests are used
to monitor the progress of the disease once it has been
diagnosed. A complete blood count, urinalysis, blood
chemistries, and erythrocyte sedimentation rate test can
provide valuable information. Another common test measures the
blood level of a group of substances called complement. Persons with lupus
often have increased erythrocyte sedimentation rates and low
complement levels, especially during flares of the disease.
Persons diagnosed with systemic lupus erythematosus
(SLE) have autoantibodies in their blood years before any
symptoms appear, according to an article in the October 16,
2003, issue of The New England Journal of Medicine.
The early detection of autoantibodies may facilitate
the recognition of those persons who will develop SLE and may
allow physicians to monitor them before the disease might
otherwise be noticed.
