Antiphospholipid syndrome

Antiphospholipid (AN-te-fos-fo-LIP-id) syndrome is a condition in which the immune system mistakenly makes antibodies that attack tissues in the body. These antibodies can cause blood clots to form in arteries and veins.

Blood clots can form in the legs, lungs and other organs, such as the kidneys and spleen. The clots can lead to heart attack, stroke and other conditions. During pregnancy, antiphospholipid syndrome also can result in miscarriage and stillbirth. Some people who have the antibodies may not have any symptoms.

There's no cure for this uncommon condition, but medicines can reduce the risk of blood clots and miscarriage.

Symptoms of antiphospholipid syndrome can include:

• Blood clots in the legs, also called deep vein thrombosis (DVT). Symptoms of DVT include pain, swelling and a change in skin color. These clots can travel to the lungs and cause a condition called pulmonary embolism.
• Repeated miscarriages or stillbirths. Other complications of pregnancy include dangerously high blood pressure, called preeclampsia, and premature delivery.
• Stroke. A stroke can occur in a young person who has antiphospholipid syndrome but no known risk factors for cardiovascular disease.
• Transient ischemic attack (TIA). Similar to a stroke, a TIA usually lasts only a few minutes and causes no permanent damage.
• Rash. Some people develop a rash with a lacy, netlike pattern.

Less common symptoms include:

• Neurological symptoms. Chronic headaches, including migraines, as well as dementia and seizures are possible when a blood clot blocks blood flow to parts of the brain.
• Cardiovascular disease. Antiphospholipid syndrome can damage heart valves.
• Low blood platelet counts, also called thrombocytopenia. This decrease in blood cells needed for clotting can cause episodes of bleeding, particularly from the nose and gums. Bleeding into the skin can appear as patches of small, discolored spots.

Seek emergency care if you have symptoms of:

• Stroke. A clot in your brain can cause sudden numbness, weakness or paralysis of your face, arm or leg. You may have trouble speaking or understanding speech, visual disturbances, and a severe headache.
• Pulmonary embolism. If a clot lodges in your lung, you may have sudden shortness of breath and chest pain or cough up blood-streaked mucus.
• Deep vein thrombosis (DVT). Symptoms of DVT include swelling, a change in skin color, or pain in a leg or arm.

Contact your healthcare professional if you have any of the following signs and symptoms of serious bleeding:

• Bleeding from the nose or gums that can't be explained.
• A heavy menstrual period that is not usual.
• Vomit that is bright red or looks like coffee grounds.
• Black, tarry stool or bright red stool.
• Abdominal pain with no explanation.

Antiphospholipid syndrome occurs when the immune system mistakenly produces antibodies that make blood much more likely to clot. Antibodies usually protect the body against invaders, such as viruses and bacteria.

Antiphospholipid syndrome can be caused by another condition, such as an autoimmune disease. You also can develop the syndrome without a known cause.

Antiphospholipid syndrome is more common in women than in men. Having another autoimmune condition, such as systemic lupus erythematosus or other connective tissue diseases, increases the risk of antiphospholipid syndrome.

It's possible to have the antibodies linked to antiphospholipid syndrome without getting symptoms. But having these antibodies increases your risk of having blood clots, particularly if you:

• Become pregnant.
• Are not mobile for a time, such as being on bed rest or sitting during a long flight.
• Have surgery.
• Smoke cigarettes.
• Take contraceptives by mouth or take estrogen therapy for menopause.
• Have high cholesterol and triglyceride levels.

Complications of antiphospholipid syndrome can include:

• Kidney failure. This can result from decreased blood flow to the kidneys.
• Stroke. Decreased blood flow to a part of the brain can cause a stroke. This can result in lasting neurological damage, such as partial paralysis and loss of speech.
• Cardiovascular problems. A blood clot in the leg can damage the valves in the veins, which keep blood flowing to the heart. This can result in chronic swelling and a change in skin color in the lower legs. Another possible complication is heart damage.
• Lung problems. These can include high blood pressure in the lungs and pulmonary embolism.
• Pregnancy complications. These can include miscarriage, stillbirth, premature delivery, slow fetal growth and dangerously high blood pressure during pregnancy, called preeclampsia.

Rarely, severe antiphospholipid syndrome can cause damage to multiple organs in a short time.