Systemic Lupus Erythematosus
DescriptionAn in-depth report on the causes, diagnosis, treatment, and prevention of Lupus.
Alternative NamesCorticosteroids; Immunosuppressant Drugs
Systemic lupus erythematosus (SLE) is one of the most serious rheumatic diseases. According to a 2002 government study, the annual number of deaths has risen from 879 to 1,406 since 1979. About third of these deaths occur in people aged 15 to 44 years, mostly women. (Such numbers may be underestimates, since SLE can affect so many organs that a cause of death in some people with SLE may not have been directly attributed to the condition.) It is important to note that a primary cause of death among patients with lupus is atherosclerosis, disease of the coronary blood vessels resulting from accelerated buildup of plaque.
SLE is unpredictable and varies greatly form one individual to the next. Severity also appears to differ among ethnic groups and countries. In Europe and North American SLE patients for example, overall five-years survival rates are between 93% and 95%, while in Asia or Africa they are considerable lower (60% to 70%). Other research also indicates that in the US African American and Hispanic patients suffer greater organ damage than Caucasian patients. Genetic factors appear to have some influence on specific effects of SLE on organ damage among ethnic groups. The poorer outlook among minority groups and in underdeveloped nations appears to be primarily due to less access to good health care.
Mild SLE. About 20% to 30% of cases are mild. For many of these patients, the only symptoms may be the skin rashes of discoid lupus erythematosus (DLE) or subacute cutaneous lupus erythematosus (SCLE) with or without joint aches. The number and intensity of symptoms in mild cases often decrease over time, as does the likelihood of major organ involvement. These skin conditions, however, are not absolute insurance against more severe disease, and patients with mild SLE should be tested for organ involvement.
Widespread SLE. Most commonly, SLE is a chronic, life-long disease, alternating between periods of symptom-relapse, or flares, and remission. The disease may begin in any of the various systems of the body and progress unpredictably to others. The following are typical patterns:
The degree of severity depends on different factors.
Because of more effective and aggressive treatment, the prognosis for SLE has improved markedly over the past two decades. Long-term progress of the disease is affected greatly by treatment in the initial acute phase of the disease so a speedy and accurate diagnosis is all-important. The 10-year survival rate with treatment is now 85% to 95% and many people have a normal life span. SLE that develops later in life is generally less serious than SLE that strikes in childhood.
Complications of the Blood
Almost 85% of SLE patients experience problems associated with abnormalities in the blood.
Anemia. About half of SLE patients are anemic. Causes include the following:
The Antiphospholipid Syndrome. Between 34% and 42% of SLE patients have the antiphospholipid syndrome (APS). This is a specific set of conditions related to the presence of autoantibodies called lupus anticoagulant and anticardiolipin. These autoantibodies react against fat molecules called phospholipids, and so are called antiphospholipids. Their actions have complex effects that include causing narrowing and abnormalities of blood vessels.
Conditions most often associated with APS include the following:
Not all patients with APS carry both of the autoantibodies, and they can also wax and wane and so have varying effects. It should also be noted that APS occurs without lupus in about half of those with the syndrome.
Thrombocytopenia. In thrombocytopenia, antibodies attack blood platelets. In such cases, blood clotting is impaired, causing bruising, bleeding from the skin, nose, gums, or intestines. (This condition can also occur in APS, but it is not considered to be one of the standard features of the syndrome.)
Neutropenia. Commonly, patients with SLE have low counts of white blood cells (a condition called neutropenia), but the condition is usually harmless unless the reductions are so severe that they leave the patient vulnerable to infections.
Acute Lupus Hemophagocyte Syndrome. A rare blood complication of SLE that occurs primarily in Asians is called acute lupus hemophagocytic syndrome. It is generally of short duration and characterized by fever and a sudden drop in blood cells and platelets.
Raynaud's phenomenon is a condition in which cold or stress can cause spasms in impaired blood vessels resulting in pain in fingers and toes. It occurs as part of the inflammatory response in blood vessels, which can narrow them and reduce circulation. In extreme cases, gangrene can result.
Heart and Circulation Complications
Cardiovascular disease is a primary cause of death in lupus patients. The immune response in SLE can cause inflammation and other damaging effects that can cause significant injury to the arteries and tissues associated with the circulation and the heart. In addition, SLE treatments (particularly corticosteroids) affect cholesterol, weight, and other factors that can also affect the heart. For decades experts have questioned the extent to which the drugs used to treat SLE were contributing to the high rate of atherosclerosis in such patients. Numerous studies now suggest that something about the disease process itself, possibly the chronic inflammation of the blood vessels, probably lies at the root of this dangerous problem. In any event, SLE patients, have a higher chance for the following conditions, which put them at risk for heart attack or stroke:
The risk for cardiovascular disease, heart attack and stroke is much higher than average in younger women with SLE; the risks decline as such women age.
SLE affects the lungs in about 60% of patients:
Kidney Complications (Lupus Nephritis)
The kidneys are a crucial battleground in SLE because it is here that the debris left over from the immune attacks is most likely to be deposited. About 50% of SLE patients exhibit inflammation of the kidneys (called lupus nephritis).This condition occurs in different forms and can vary widely in severity.
Serious complications occur eventually in about 30% of patients. If kidney injury develops, it almost always occurs within 10 years of the onset of SLE, rarely after that.
Central Nervous System Complications
Nearly all SLE patients report some symptoms relating to problems that occur in the central nervous system (CNS), which includes the spinal cord and the brain. Most of these symptoms are minor and some, such as headache, may be related to depression rather than the disease itself. CNS involvement is more likely to occur in the first year, usually during flare-ups in other organs. Symptoms vary widely and may be indistinguishable from psychiatric or neurologic disorders or from the side effects of some medications used for SLE. They include the following:
Central nervous system symptoms are usually transient and mild, although, unfortunately, there is little effective treatment available for them. The severity of CNS symptoms correlates with progression of the disease.
Infections are a common complication and a major cause of death in all stages of SLE. The immune system is indeed overactive in SLE, but it is also abnormal and reduces the ability to fight infections. Patients are not only prone to the ordinary streptococcal and staphylococcal infections, but they are also susceptible to fungal and parasitic infections (called opportunistic infections), which are common in people with weakened immune systems. They also face an increased risk for herpes, salmonella, and yeast infections. Corticosteroid and immunosuppressants, treatments used for SLE, also increase the risk for infections, thereby compounding the problem.
About 45% of SLE patients suffer gastrointestinal problems, including nausea, weight loss, mild abdominal pain, and diarrhea. Severe inflammation of the intestinal tract occurs in less than 5% of patients and causes acute cramping, vomiting, diarrhea, and, rarely, intestinal perforation, which can be life-threatening. Fluid retention and swelling can cause intestinal obstruction, which is much less serious but causes the same type of severe pain. Inflammation of the pancreas can be caused by the disease and by corticosteroid therapy.
Joint, Muscle, and Bone Complications
Arthritis caused by SLE almost never leads to destruction or deformity of joints. The inflammatory process can, however, damage muscles and cause weakness. SLE patients also commonly experience reductions in bone mass density (osteoporosis) and have a higher risk for fractures, whether or not they are taking corticosteroids (which are known risk factors for osteoporosis).
Inflamed blood vessels in the eye can reduce blood supply to the retina, resulting in degeneration of nerve cells and a risk of hemorrhage in the retina. The most common symptoms are cotton-wool-like spots on the retina. In about 5% of patients sudden temporary blindness may occur.
In one study, 40% of SLE patients quit work within four years of diagnosis, and many had to modify their work conditions. Significant factors that predicted job loss included high physical demands from the work itself, a more severe condition at the time of diagnosis, and lower educational levels. People with lower income jobs were at particular risk for leaving them.