Systemic lupus erythematosus (SLE) can cause complications throughout the body.
Blood problems are common with SLE.
About one half of patients with SLE are anemic. Causes include:
- Iron deficiencies resulting from excessive menstruation
- Iron deficiencies from gastro-intestinal bleeding caused by some of the treatments
- A specific anemia called hemolytic anemia, which destroys red blood cells
- Anemia of chronic disease
Hemolytic anemia can occur with very high levels of the anticardiolipin antibody. It can be chronic or develop suddenly and be severe (acute).
Many patients with SLE have antiphospholipid syndrome (APS). This is a disorder of blood coagulation related to the presence of autoantibodies called lupus anticoagulant and anticardiolipin antibodies. APS can cause blood clots, which most often occur in the deep veins of the legs, a condition called deep vein thrombosis. Blood clots increase the risk for stroke and pulmonary embolism (clots in the lungs). Patients with APS are also at high risk for pregnancy complications, including miscarriage (see Pregnancy Complications below).
Vasculitis is an inflammation of the blood vessels. If it becomes severe, it can cause blood to stop flowing to organs and tissues, resulting in damage to the tissue and potentially life-threatening complications.
In thrombocytopenia, antibodies attack and destroy blood platelets. In such cases, blood clotting is impaired, which causes bruising and bleeding from the skin, nose, gums, or intestines.
Leukopenia and Neutropenia
These conditions cause a drop in the number of white blood cells. Severe reductions in white blood cell counts can increase the risk for infections.
Patients with SLE and other autoimmune disorders have a greater risk of developing lymph system cancers such as Hodgkin disease and non-Hodgkin lymphoma (NHL).
The risk for coronary artery disease, heart attack, and stroke is much higher than average in patients with SLE, and heart disease is a primary cause of death. The chronic inflammation associated with SLE can cause plaque buildup (atherosclerosis) in the heart's arteries, which can lead to coronary heart disease and heart attack. SLE also affects blood vessels and circulation. In addition, SLE treatments (particularly corticosteroids) can affect cholesterol, weight, and other factors that harm the heart.
Patients with SLE have an increased risk of developing the following conditions, which put them at risk for heart attack or stroke:
- Atherosclerosis, or plaque buildup in the arteries
- Unhealthy cholesterol and lipid (fatty molecules) levels
- High blood pressure, often associated with kidney damage and corticosteroid treatments
- Heart failure
- Pericarditis, inflammation of the tissue surrounding the heart
- Endocarditis, inflammation in the lining of the heart
- Myocarditis, inflammation of the heart muscle itself
- Coronary vasculitis, inflammation of the blood vessels of the heart
- Valvular abnormalities
SLE affects the lungs in several ways:
- Pleurisy. A common problem is inflammation of the membrane lining the lung, which can cause shortness of breath and coughing.
- Pleural effusion. Accumulation of fluid in the lungs.
- Lupus pneumonitis. Inflammation of the lung tissue, which can be acute (short-term) or chronic (long-term). Symptoms include chest pain, difficulty breathing, and a dry cough that may bring up blood. Lupus pneumonitis may cause scarring of lung tissue. Fortunately, this condition is relatively rare.
- Pulmonary hypertension. Another serious but rare condition. It occurs when high pressure develops in the pulmonary arteries as a result of damage to the blood vessels of the lungs.
- Blood clots in the lungs (pulmonary embolism) can travel from deep veins in the legs. This problem is linked to the antiphospholipid syndrome (APS).
Kidney Complications (Lupus Nephritis)
Kidney complications such as inflammation of the kidneys (lupus nephritis) are common in SLE and are a significant cause of morbidity and mortality in lupus. About one third of patients have lupus nephritis at the time of diagnosis and more than one half develop it within 10 years after lupus symptoms begin. In its early stages, lupus nephritis can cause fluid buildup leading to swelling in the extremities (feet, legs, hands, arms) and overall weight gain. Lupus nephritis may progress to kidney failure (end-stage renal disease), a severe condition that requires lifelong treatment with hemodialysis or even kidney transplant. Periodic screening for kidney disease is important for all patients with SLE.
Central Nervous System Complications
Nearly all patients with SLE report some symptoms relating to problems that occur in the central nervous system (CNS), which includes the spinal cord and the brain. SLE can also affect the peripheral nervous system, which transmits and receives motor and sensory information from the central nervous system.
Symptoms vary widely and may overlap with psychiatric or neurologic disorders. They may also be caused by of some medicines used for treating SLE.
CNS complications associated with SLE include:
- Problems with thinking, concentration and memory, commonly known as "lupus fog."
- Migraine and tension-type headaches.
- Emotional disorders (anxiety, depression).
- Problems with the reflexes, sensation, vision, hearing, and motor control. These abnormalities can be due to inflammation in the cranial or peripheral nerves or in the spinal cord itself.
- CNS vasculitis is a serious but very rare disorder caused by inflammation of the blood vessels of the brain.
- Strokes can be due to the APS.
Immune System Complications
Infections are a common complication and a major cause of death in all stages of SLE. Patients are not only prone to the ordinary bacterial and viral infections, but they are also susceptible to fungal and parasitic infections, which are common in people with weakened immune systems. They also face an increased risk for urinary tract, herpes, salmonella, and yeast infections. Corticosteroid and immunosuppressant drug treatments used for SLE also increase the risk for infections.
Many patients with SLE suffer gastrointestinal problems, including nausea, weight loss, mild abdominal pain, diarrhea, and gastroesophageal reflux disorder (heartburn). SLE can also affect organs located in the gastrointestinal system, such as the liver, gallbladder, pancreas, and bile ducts.
Joint, Muscle, and Bone Complications
Patients with SLE often experience muscle aches and weakness. Lupus can also cause pain, stiffness, and swelling in the joints. Lupus arthritis varies in severity from mild to deforming. Knees, wrists, and the small joints of the hand are most commonly affected. Patients with SLE also commonly experience reductions in bone mass density (osteoporosis) and have a higher risk for fractures, whether or not they are taking corticosteroids (which can increase the risk for osteoporosis). Women who have SLE should have regular bone mineral density scans to monitor bone health.
Many patients with SLE have problems with dry eyes. Retinal vascular lesions (blood vessel damage due to reduced blood flow) are also common and may affect vision. Nerve damage in the eyes can also cause poor vision as well as droopy eyelids. It is not uncommon for patients with SLE to also have Sjögren syndrome, another type of autoimmune disorder characterized by dry eyes. Certain antimalarial drugs, especially hydroxychloroquine, used to treat SLE can also cause eye complications.
Women with lupus face a higher risk for pregnancy complications, including miscarriage, premature birth, and preeclampsia. The risk for miscarriage is highest for patients with antiphospholipid antibodies, which can cause blood clotting in the placenta. Lupus patients with active kidney disease are at increased risk for preeclampsia (a pregnancy complication that includes high blood pressure and fluid buildup). Pregnant women who take corticosteroids face increased risks for gestational diabetes and high blood pressure.
Despite these obstacles, many women with lupus have healthy pregnancies and deliver healthy babies. To increase the odds of a successful pregnancy, it is important for women to plan carefully before becoming pregnant. (See "Pregnancy and SLE" in Treatment section of this report.)