What is lupus?
Systemic lupus erythematosus (lupus) is a disease of the immune system. Normally, the immune system protects the body from infection. However, in lupus, the immune system inappropriately attacks tissues in various parts of the body. This abnormal activity of the immune system leads to tissue damage and illness.
Who is affected by lupus?
Lupus can affect men and women of any race or age. One in 2,000 people in the United States has lupus. People of African, Asian and Native American descent are more likely to develop lupus than are Caucasians. In addition, the disease develops in Emiratis at an earlier stage compared to Asians and expatriate Arabs working in UEA. Lupus studies also show racial preferences, being more prevalent among Arabs than Asians in the UAE region.
Areas of the body which may be affected during the course of lupus are shown in this drawing. The blood may also be affected.
If only women of childbearing age (14 to 45 years old) are considered, as many as 1 in 250 may develop lupus. This suggests a possible role for female hormones influencing vulnerability to this disease.
Symptoms and Causes
What problems may lupus patients develop?
Many patients with active lupus feel poorly in general and complain of fever, weight loss and tiredness. Patients with lupus also develop specific problems when the immune system attacks a particular organ(s) or area(s) in the body.
Specific areas of the body that may be affected during the course of lupus include the skin, joints, and kidneys. The blood may also be affected during the course of lupus, resulting in low red blood cell count (anemia), low white blood cell count and low platelet count.
Skin problems are a common feature of lupus. Some patients with lupus have a red rash over their cheeks and the bridge of their nose. Because the location of this rash is the same as the common markings of a wolf, the name "lupus" (wolf in Latin) was given to this disease many years ago.
Other skin problems that occur include large red, circular rashes (plaques), which may scar (called discoid lupus). Skin rashes are usually aggravated by sunlight.
Hair loss and mouth sores are also common.
Arthritis is very common in people who have lupus. There may be pain, with or without swelling. Stiffness and pain may be especially evident in the morning. Arthritis may be a problem for only a few days to weeks or may be a permanent feature of the disease. Fortunately, arthritis is usually not crippling.
Kidney involvement in people with lupus is potentially life threatening and may occur in up to half of lupus patients. Kidney problems may become apparent when lupus patients feel ill with arthritis, have a rash, fever and weight loss. Less often, kidney disease may occur when there are no other symptoms of lupus. Kidney disease itself usually does not produce symptoms until it is in the advanced stages. It is important that kidney disease be diagnosed early and treated appropriately. The earliest signs of kidney disease are apparent from a urinalysis.
Blood involvement can occur with or without other symptoms. Patients may have dangerous reductions in the number of red blood cells, white blood cells or platelets (cells that help clot the blood).
Sometimes changes in blood counts may contribute to symptoms of fatigue (low red blood cell count, anemia), serious infections (low white blood cell count), or easy bruising (low platelet count). However, many patients do not have symptoms that indicate blood abnormalities, so it is important for lupus patients to have periodic blood tests in order to detect any problems.
Blood clots are seen with increased frequency in lupus. Clots often occur in the legs (a vein clot, called deep venous thrombosis), lungs (a lung clot, called pulmonary embolus), or brain (stroke). Blood clots that develop in lupus patients may be associated with the production of antiphospholipid antibodies. These antibodies are abnormal proteins that may increase the tendency of the blood to clot.
Heart and lungs
Heart and lung involvement is often caused by inflammation of the covering of the heart (pericardium) and lungs (pleura). When these structures become inflamed, patients may develop chest pain, irregular heartbeat and accumulation of fluid around the lungs (pleuritis or pleurisy) and heart (pericarditis).
What causes lupus?
The cause of lupus is unknown. Finding the cause is the object of major research efforts.
Factors that may contribute to the cause of lupus include viruses, environmental chemicals, and the person's genetic makeup.
Female hormones are believed to play a role in the development of lupus because women are affected more commonly than men. This is especially true of women during their reproductive years, a time when hormone levels are highest.
The observation that lupus may affect more than one member of the same family has raised the possibility that the tendency to develop lupus may be inherited. Having such a tendency, however, does not predict that a relative will develop lupus. About 10 percent of lupus patients have a close relative with lupus.
Diagnosis and Tests
How is lupus diagnosed?
The diagnosis of lupus is best made by an experienced clinician who fully understands the disease and other diseases with similar features that can mimic lupus. The diagnosis is made when a patient has several features of the disease (including symptoms, findings on examination and blood test abnormalities). The American College of Rheumatology has devised criteria to assist clinicians in making the correct diagnosis of lupus.
Does a positive antinuclear antibody (ANA) test indicate lupus?
Not necessarily. The antinuclear antibody (ANA) test is positive in most patients with lupus, but it may also be positive in many people who do not have lupus. Therefore, a positive ANA test alone is not adequate for the diagnosis of lupus -- there must be at least three additional clinical features for the diagnosis to be made.
Management and Treatment
How is lupus treated?
The type of treatment prescribed will depend on several factors, including the person's age, type of medications he or she is taking, overall health, medical history and location and severity of disease.
Because lupus is a condition that can change over time and is not always predictable, a critical part of good care includes periodic visits with a knowledgeable, available physician.
Some patients with mild features of the disease do not require treatment, while patients with serious involvement (such as kidney complications) may require the use of powerful medications. Medications used to treat lupus include:
- Steroids or prednisone and related derivatives of cortisone. Steroid creams can be directly applied to rashes. The use of creams is usually safe and effective, especially for mild rashes. The use of steroid creams or pills in low doses can be effective for mild or moderate features of lupus. Steroids can also be used in higher doses when internal organs are threatened. Unfortunately, high doses are also most likely to produce side effects.
- Hydroxychloroquine (Plaquenil®) is commonly used to help keep mild lupus-related problems, such as skin and joint disease, under control.
- Cyclophosphamide (Cytoxan®) is a chemotherapy drug that has very powerful effects on reducing the activity of the immune system. It is used to treat severe forms of lupus.
- Azathioprine (Imuran®) is a medication originally used to prevent rejection of transplanted organs. It is commonly used to treat the more serious features of lupus.
- Methotrexate (Rheumatrex®) is another chemotherapy medication used to suppress the immune system. Its use is becoming increasingly popular for skin disease, arthritis, and other non-life threatening forms of disease that have not responded to medications such as hydroxychloroquine or low doses of prednisone.
- Cyclophosphamide (Cytoxan®) and mycophenolate mofetil (CellCept®) are chemotherapy drugs that have very powerful effects on reducing the activity of the immune system. They are used to treat more severe forms of lupus, especially lupus that affects the kidneys.
- Belimumab (Benlysta®) is a monoclonal antibody that reduces the activity of white blood cells (lymphocytes) that make autoantibodies. Autoantibodies are important as they cause tissue damage. Belimumab is used to treat lupus that does not involve the kidneys and has not responded to other types of treatments.
- Rituximab (Rituxan®) is also a monoclonal antibody that reduces the activity of white blood cells (lymphocytes) that make autoantibodies. It is sometimes used to treat lupus that has not responded to other types of treatments.