Lupus is a disease that affects more individuals than AIDS, cerebral palsy, multiple sclerosis and cystic fibrosis combined, yet it is largely unfamiliar to the general public. Jennifer Paterson investigates a potentially life threatening illness.
What is lupus?
Lupus is an autoimmune disease, which can be mild or life threatening. The disease affects the immune system causing it to become hyperactive - attacking normal tissue. It causes tissues to become inflamed, and any part of the body can be affected. The disease can result in a wide variety of symptoms such as joint or muscle pain, skin rash, kidney problems, headaches and in serious cases - seizures. Symptoms will vary depending on which part of the body the disease targets.
What does 'autoimmune' mean?
It quite literally means that the body fights its own immune system. Inflammation is generally the body's defence mechanism, used to eliminate a foreign body or organism (such as a bacteria or virus). In an autoimmune disease the body makes a 'mistake' and reacts to its own tissues. When inflammation occurs for an extended period of time, such as with a disease like lupus, tissue damage can result, impairing normal bodily functions.
What causes lupus? At this stage the exact cause of lupus is not known. Research has established that the disease has a genetic component, as it affects women of child bearing age more frequently. It is suspected that people inherit characteristics which predispose them to develop lupus, with certain 'triggers' providing the right environment for the disease to develop.
What can trigger lupus?
Certain factors are believed to trigger the onset of lupus, or cause lupus to flare up. These include:
Ultra Violet light (UV)
Certain prescription drugs
It has also been suggested that extreme stress may play a role in triggering lupus. Anecdotal reports from many sufferers have related lupus flare-ups to stressful periods, but this has not been confirmed scientifically.
Systemic lupus is quite difficult to diagnose for a number of reasons.
1. The disease develops slowly, often over months or years, and symptoms can come and go.
2. The disease often mimics other diseases.
3. The disease is a 'multi-system' disease, requiring many symptoms in different body parts to be diagnosed.
4. There is no single diagnostic test for lupus.
So how is it diagnosed?
An anti-nuclear antibody test is used as a screening test in suspected cases of lupus. However, a positive result is not necessarily proof of Lupus. The test is only an indicator. Many people may have a positive ANA test, yet do not have the disease. Doctors have to gather information from a variety of sources - past medical history, lab tests and current symptoms - and a person must satisfy at least 4 of 11 diagnostic criteria before lupus can be pinpointed.
What type of research is being conducted into lupus? Researchers at the Garvan Institute have been investigating the the BAFF gene (B cell Activation Factor) as a possible cause of lupus. It was chosen as a potential candidate because its gene sequence is similar to that of other proteins which are of importance to the immune system.
They have discovered that mice who produce too much BAFF get sick, and have symptoms reminiscent of systemic lupus ertymatosis (SLE). Marcel Batten, a researcher in the Arthritis and Inflammation Research Progam comments "the work we have been doing aims to describe how excess BAFF may be involved in autoimmune disease."
Therapies that block BAFF show a great deal of promise for the treatment of autoimmune disease. It has been shown that blocking BAFF can increase the lifespan of mice with lupus-like disease. Marcel adds that "our research will further the understanding of autoimmune diseases, including lupus. If we can understand the cause of the disease we can create effective treatments."
Date written: October 11, 2000