Antiphospholipid (AN-te-fos-fo-LIP-id) syndrome occurs when your immune system attacks some of the normal proteins in your blood. It can cause blood clots in your arteries or veins. And it can cause pregnancy complications, such as miscarriage and stillbirth.
Blood clots in your leg veins cause a condition known as deep vein thrombosis (DVT). Damage from blood clots in your organs, such as your kidneys, lungs or brain, depends on the extent and location of the clot. For instance, a clot in your brain can cause a stroke.
There’s no cure for antiphospholipid syndrome, but medications can reduce your risk of blood clots.
Signs and symptoms of antiphospholipid syndrome can include:
- Blood clots in your legs (DVT). The clots can travel to your lungs (pulmonary embolism).
- Repeated miscarriages or stillbirths. Other complications of pregnancy include premature delivery and high blood pressure during pregnancy (preeclampsia).
- Stroke. A stroke can occur in a young person who has antiphospholipid syndrome but no known risk factors for cardiovascular diseases.
- Transitory 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 red rash with a lacy, net-like pattern (livedo reticularis).
Less common signs and symptoms include:
- Neurological symptoms. Chronic headaches, including migraines; dementia and seizures are possible when a blood clot blocks blood flow to parts of your brain.
- Cardiovascular disease. Antiphospholipid syndrome can damage heart valves.
- Bleeding. Some people have a decrease in blood cells needed for clotting (platelets). If you have this condition (thrombocytopenia), you might have few or no symptoms.
However, if your platelet count drops too low, you might have episodes of bleeding, particularly from your nose and gums. You can also bleed into your skin, which will appear as patches of small red spots (petechiae).
Antiphospholipid syndrome affects women much more than it does men. Other risk factors include:
- Having an autoimmune condition, such as systemic lupus erythematosus or Sjogren’s syndrome
- Having certain infections, such as syphilis, HIV/AIDS, hepatitis C or Lyme disease
- Taking certain medications, such as hydralazine for high blood pressure, the heart rhythm-regulating medication quinidine, the anti-seizure medication phenytoin (Dilantin) and the antibiotic amoxicillin
- Having a family member with antiphospholipid syndrome
Risk factors for developing symptoms
It’s possible to have the antibodies associated with antiphospholipid syndrome without developing signs or symptoms. However, having these antibodies increases your risk of developing blood clots, particularly if you:
- Become pregnant
- Are immobile for a time, such as being on bed rest or sitting during a long flight
- Have surgery
- Smoke cigarettes
- Take oral contraceptives or estrogen therapy for menopause
- Have high cholesterol and triglycerides levels
Depending on which organ is affected by a blood clot and how severe the obstruction of blood flow to that organ is, untreated antiphospholipid syndrome can lead to permanent organ damage or death. Complications include:
- Kidney failure. This can result from decreased blood flow to your kidneys.
- Stroke. Decreased blood flow to a part of your brain can cause a stroke, which can result in permanent neurological damage, such as partial paralysis and loss of speech (aphasia).
- Cardiovascular problems. A blood clot in your leg can damage the valves in the veins, which keep blood flowing to your heart. This can result in chronic swelling and discoloration in your lower legs (chronic venous insufficiency). Another possible complication is heart damage.
- Lung problems. These can include high blood pressure in your lungs (pulmonary hypertension) and pulmonary embolism.
- Pregnancy complications. These can include miscarriages, stillbirths, premature delivery, slow fetal growth and high blood pressure during pregnancy (preeclampsia).
Doctors generally use medications that reduce your blood’s tendency to clot to help prevent complications of antiphospholipid syndrome.
Standard initial treatment
If you have thrombosis, standard initial treatment involves a combination of blood-thinning (anticoagulant) medications.
- Heparin. Typically, you’ll first be given an injection of the blood thinner heparin, combined with another blood thinner in pill form, likely warfarin (Coumadin, Jantoven).
- Warfarin. After several days of combined heparin and warfarin, your doctor might discontinue the heparin and continue the warfarin, possibly for the rest of your life.
- Aspirin. In some cases, your doctor might recommend adding low-dose aspirin to your treatment plan.
When you’re taking anticoagulant medication, you have an increased risk of bleeding episodes. Your doctor will monitor your dosage with blood tests to be sure your blood is capable of clotting enough to stop the bleeding of a cut or the bleeding under the skin from a bruise.
Treatment during pregnancy
During pregnancy, treatment to keep your blood from clotting increases your chances of carrying to term. Treatment includes:
- Heparin. Some forms of heparin — enoxaparin (Lovenox) and dalteparin (Fragmin) — are known as low-molecular-weight heparin, which you can inject yourself under your skin (subcutaneously). Heparin is considered safe to take during pregnancy.
- Aspirin. If you’re pregnant, your doctor might recommend taking one tablet of aspirin daily in addition to the heparin, to increase your chances of a successful pregnancy.
Possible future treatments
Several new treatments are being considered for antiphospholipid syndrome, including:
- New blood thinners (anticoagulants). A number of oral blood thinners — dabigatran (Pradaxa), rivaroxaban (Xarelto) and apixaban (Eliquis) — have recently been approved to treat other conditions. It’s not clear yet if these drugs are appropriate for treating antiphospholipid syndrome. None is recommended for use during pregnancy or breast-feeding.
- Rituximab (Rituxan). This drug has been used successfully to treat conditions affecting the immune system. But there isn’t yet enough evidence of benefit to recommend rituximab as a treatment for antiphospholipid syndrome.