Lupus
Lupus, or systemic lupus erythematosus (SLE), is an autoimmune
disease that causes various tissues in the body to become chronically
inflamed. A healthy immune system makes proteins called antibodies that
protect the body against invading bacteria, viruses and other foreign
material. Lupus is the result of mistaken identity: the immune system
produces antibodies, called auto-antibodies, that mistakenly attack the
body’s own healthy tissue, in particular the joints, skin, blood and
kidneys.
The auto-antibodies damage healthy tissue, resulting in
inflammation. Inflammation is a protective process involving the action
of several types of immune cells to help prevent and heal damage. The
symptoms are brought on by the body’s own repair mechanisms as they
deal with the damaged tissue.
Lupus was once considered a life-threatening disease but in recent years increased understanding and appropriate treatments have led to better outcomes, and the quality of life of those with the disease has been greatly improved.
Why the immune system attacks itself is unknown. Research is
providing a greater understanding of how the immune system functions,
allowing scientists to work out what goes wrong in autoimmune diseases.
Lupus tends to be concentrated in certain families and ethnic groups,
suggesting a genetic component to the disease, although no genes have
yet been identified with it. Scientists also think that environmental
factors can trigger lupus, including infections, stress and diet.
Hormonal factors may explain why lupus occurs more frequently in women
during the reproductive ages of 15 to 45 years, because recent studies
support the theory that the female hormone oestrogen plays a role in
immune system action.
The disease is chronic (persistent), punctuated by ‘flare-ups’ –
periods when the symptoms appear. During a flare-up, patients usually
feel generally unwell, weak and fatigued. These flare-ups may be
triggered by sunlight, infection, certain medications and even some
foods.
At the site of affected tissue, the signs of inflammation include
swelling, redness, pain and heat. Because lupus can affect a variety of
areas of the body, such as the lungs, heart, liver, brain and the
reproductive and nervous systems, the symptoms can vary depending on
which tissues are targeted.
Some common symptoms include:
•Painful inflammation of one or more joints, which may cause the
disease to be mistaken for rheumatoid arthritis
•Red rashes on various parts of the body, but most often on the face: a
butterfly-shaped rash on the cheeks and across the nose is a
distinguishing sign of the disease
•Reduction in blood cell numbers, which may cause anaemia, making the
body more vulnerable to infection and preventing blood from clotting
properly
•Kidney failure due to severe inflammation and immune cell blockage of
the blood vessels
There is currently no cure for lupus, but there is effective
treatment that will bring the disease under control. The aim of
treating lupus is to minimize the symptoms and reduce the inflammation
of affected tissues. Learning to recognise the warning signs and
patterns of a flare-up can also help patients to better manage the
disease.
The Lupus
Foundation of America has reported that anti-malarial drugs can
control lupus. Anti-malarials appear to interfere with immune cell
enzymes by raising the pH inside cells. This alters many chemicals
involved in the inflammation response, producing an anti-inflammatory
effect and thinning the blood by altering platelet aggregation.
Further, anti-malarials combine with immune signallers such as
cytokines, decreasing the production of auto-antibodies and inhibiting
the proliferation of lymphocytes (a form of white blood cell).
Several groups of scientists at Garvan are focusing on understanding
how and why the immune system turns on itself. The Autoimmine Disease
Mechanisms is studying a molecule called B Cell Activating Factor
(BAFF) and its role in lupus. Using a strain of laboratory animal that
develops a lupus-like disease, they have found that dysfunction of this
molecule may be an underlying factor in autoimmune disease. They have
shown that excess BAFF increases a subset of B immune cells with
potential to cause autoimmunity. Their recent research has found that
these B cells express a specific target molecule called CXCR7 that may
have a role in the autoimmune response. By identifying target
molecules, researchers can develop therapies aimed at destroying those
cells that attack and damage healthy tissue.
News
Have we uncovered a new form of Lupus?
31 Jul 2007
Findings published in the July edition of the prestigious Journal of Experimental Medicine may offer new hope to people suffering from a previously unsuspected form of lupus. The research, undertaken by Garvan's Professor Fabienne Mackay, suggests a form of the disease that does not respond to current treatments. If proven to be correct, her findings will change clinical thinking and so bring about changes in patient management and in clinical trial protocols.
