Antiphospholipid syndrome occurs when your immune system mistakenly attacks some of the normal proteins in your blood. Antiphospholipid syndrome can cause blood clots to form within your arteries or veins. It can also cause pregnancy complications, such as miscarriage and stillbirth.
Antiphospholipid syndrome may cause blood clots to form in your leg veins, a condition known as deep vein thrombosis (DVT). Antiphospholipid syndrome may also cause blood clots to form in organs such as your kidneys or lungs. Damage depends on the extent and location of the clot. For instance, a clot in your brain can cause stroke.
There's no cure for antiphospholipid syndrome, but medications can be effective in reducing your risk of blood clots.
Signs and symptoms of antiphospholipid syndrome may include:
Blood clots in your legs (deep vein thrombosis, or DVT) that may travel to your lungs (pulmonary embolism)
Repeated miscarriages or stillbirths and other complications of pregnancy, such as premature delivery and high blood pressure during pregnancy (preeclampsia)
Blood clots in the arteries of your arms or legs (peripheral arterial thrombosis)
Other 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.
Rash. Some people develop a red rash with a lacy, net-like pattern (livedo reticularis).
Cardiovascular disease. Heart valves can be damaged in people with antiphospholipid syndrome.
Bleeding. Some people experience a decrease in platelets, blood cells necessary for normal clotting. If you have this condition (thrombocytopenia), you may have few or no symptoms. However, if your platelet count drops too low, you may 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).
Infrequent signs and symptoms include:
Movement disorder, in which your body and limbs jerk uncontrollably (chorea)
Cognitive problems, such as poor memory
Sudden hearing loss
When to see a doctor
If you already have an autoimmune condition, talk to your doctor about whether you should be tested for antiphospholipid antibodies.
Other reasons to contact your doctor include:
Pain or swelling in your leg or arm. See your doctor especially if an area of your leg or arm is red, swollen or tender. Seek emergency care if vein swelling and pain are severe or are accompanied by chest pain or shortness of breath, which could indicate DVT and an increased chance of a blood clot traveling to your lungs (pulmonary embolism).
Vaginal spotting or bleeding during pregnancy. This may be a sign of miscarriage or other pregnancy problems. However, many women spot or bleed and are able to have a healthy pregnancy. If you've had repeated pregnancy losses or unexplained severe complications of pregnancy, it could be related to antiphospholipid syndrome. Talk to your doctor about whether testing would be right for you.
If you have antiphospholipid syndrome and you're thinking of attempting pregnancy, treatments are available during your pregnancy. But be sure to seek the care of an expert obstetrical provider to discuss your options.
When it's an emergency
Seek emergency care if you have certain other serious signs and symptoms. Look for:
Signs and symptoms of stroke. These include sudden numbness, weakness or paralysis of your face, arm or leg; sudden difficulty speaking or understanding speech; sudden visual disturbances; sudden, severe headache; and dizziness.
Signs and symptoms of pulmonary embolism. These include sudden shortness of breath, chest pain and coughing up blood-streaked sputum.
Signs and symptoms of deep vein thrombosis. These include the development of leg swelling or pain.
Other signs of bleeding. These include unexplained bleeding from your nose or gums; an unusually heavy menstrual cycle; vomit that is bright red or looks like coffee grounds; black, tarry stool or bright red stool; and unexplained abdominal pain.
The role of phospholipids
In antiphospholipid syndrome, your body mistakenly produces antibodies against proteins that bind phospholipids, a type of fat present in your blood that plays a key role in clotting (coagulation). Antibodies are specialized proteins that normally attack body invaders, such as viruses and bacteria. When antibodies attack your phospholipid-binding proteins, your blood may clot abnormally.
There are two main classifications of antiphospholipid syndrome:
Primary. If there's no known underlying reason, such as an autoimmune disorder, you have primary antiphospholipid syndrome.
Secondary. If you have systemic lupus erythematosus or another autoimmune disorder, certain infections, or have taken certain medications, your antiphospholipid syndrome is secondary. The cause of your antiphospholipid syndrome is considered to be the underlying condition or medication.
Some factors are associated with developing antiphospholipid antibodies — though not necessarily with developing the syndrome. They include:
Infections. People with certain infections, including syphilis, HIV infection, hepatitis C and Lyme disease, among others, have a higher incidence of having antiphospholipid antibodies.
Medications. The high blood pressure medication hydralazine, the heart rhythm-regulating medication quinidine, the anti-seizure medication phenytoin (Dilantin) and the antibiotic amoxicillin may lead to an increased risk of developing antiphospholipid antibodies.
Genetic predispositions. Although the disorder isn't considered hereditary, research indicates that relatives of people with antiphospholipid syndrome are more likely to have the antibodies.
Risk factors for antiphospholipid syndrome 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 ever developing signs or symptoms. However, if you have these antibodies, your risk of developing blood clots increases particularly if you:
Remain immobile for a period of time (such as when you're on bed rest or sitting during a long airline flight)
Take oral contraceptives
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 damage or death. Complications may 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. If a clot forms in your leg (deep vein thrombosis), the clot can damage the valves in the veins in your affected leg, which normally serve to keep the blood flowing upward to your heart. This may result in a condition called chronic venous insufficiency, which causes chronic swelling and discoloration in your lower legs, because of the impaired blood flow upward to your heart. Another possible complication is heart damage.
Lung problems. Complications related to your lungs may include high blood pressure in your lungs (pulmonary hypertension) and pulmonary embolism.
Pregnancy complications. These may include miscarriages, stillbirths, premature delivery and high blood pressure during pregnancy (preeclampsia).
In most cases, it's the complications of antiphospholipid syndrome — such as deep vein thrombosis, stroke or pregnancy loss — that will prompt you to seek medical care. Depending on your complication, you'll likely see a specialist. For deep vein thrombosis, for instance, you may meet with a specialist in vascular disease, obstetrics or hematology. You're more likely to see a specialist if testing done for unexplained clotting or pregnancy loss shows antiphospholipid antibodies.
Because appointments can be brief and because there's often a lot of ground to cover, it's a good idea to be well-prepared. Here's some information to help you get ready, including what to expect from the doctor.
What you can do
Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance.
Write down any signs or symptoms you've had, including any that may seem unrelated to your main health problem.
Write down key personal information, including any major recent events or changes in your life.
Make a list of your key medical information, including other conditions or infections with which you've been diagnosed. Be sure to mention if any close relatives have had antiphospholipid syndrome. Also write down the names of any medications, vitamins or supplements you're taking.
Consider taking a family member or friend along. Sometimes it can be difficult to remember all of the information provided during an appointment. Someone who accompanies you may remember something that you missed or forgot.
Write down questions to ask your doctor.
Your time with your doctor is limited, so preparing a list of questions will help you make the most of your time together. List your questions from most important to least important in case time runs out.
For antiphospholipid syndrome, some basic questions to ask your doctor include:
What's the most likely cause of my symptoms?
What kinds of tests do I need?
What treatment do you recommend?
Will I need to take medications long term?
What are the possible side effects of the medications you're prescribing?
How will you determine whether my treatment is working?
Does this condition increase my risk of any other medical problems?
Does this condition increase my risk of health problems during pregnancy? Are treatment options available to reduce that risk?
Are there any brochures or other printed material that I can take with me? What websites do you recommend?
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask additional questions during your appointment.
What to expect from your doctor
Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over points you want to talk about in-depth. Your doctor may ask:
Do you have a history of stroke or blood clots?
Do you have a history of pregnancy complications, such as high blood pressure, miscarriage or stillbirth?
Do you have lupus or another autoimmune disorder?
Have you ever been tested for sexually transmitted infections or chronic viral diseases, such as hepatitis?
Have you experienced frequent headaches?
Have you noticed a red, net-like rash on your wrists or knees?
Do you smoke?
Do any of your close relatives have antiphospholipid syndrome?
If you have one or more episodes of thrombosis or pregnancy loss that are not explained by known health conditions, your doctor can schedule blood tests to check for abnormal clotting and for the presence of antibodies to phospholipid-binding proteins.
Blood tests for antiphospholipid syndrome look for at least one of the following three antibodies in your blood:
Beta-2 glycoprotein I
To confirm a diagnosis of antiphospholipid syndrome, the antibodies must appear in your blood at least twice, in tests conducted at least 12 weeks apart.
Doctors generally use medications that reduce your blood's tendency to clot to treat antiphospholipid syndrome. This doesn't cure the disease but does help to prevent its most serious complications.
Standard initial treatment
If you have thrombosis, standard initial treatment involves a combination of anticoagulant (blood-thinning) 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).
Warfarin. After several days of combined heparin and warfarin, your doctor may discontinue the heparin and continue the warfarin, possibly for the rest of your life.
Aspirin. In some cases, your doctor may recommend adding low-dose aspirin to your treatment plan.
When you're taking anticoagulant medication, 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
Anticoagulation therapy is more complex during pregnancy. The therapy is expensive, requires regular injections and carries some significant risks of side effects.
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 may recommend taking one tablet of aspirin daily in addition to the heparin, to increase your chances of a successful pregnancy.
Rarely, warfarin can cause birth defects, so it isn't recommended for use during pregnancy. In rare cases, a doctor may prescribe warfarin during pregnancy if the benefits of using it outweigh the risks.
Although anticoagulation therapy during pregnancy may be complicated, the good news is that it usually prevents antiphospholipid syndrome-related miscarriage.
Throughout your pregnancy, your doctor will monitor your dosage of blood-thinning medication with blood tests. These tests ensure that your blood is capable of clotting enough to stop the bleeding of a cut or the bleeding under the skin from a bruise.
Several new treatments are being considered for antiphospholipid syndrome, including:
Statins. These medications are normally used to lower cholesterol, but they may lessen the risk of blood clots and cardiovascular disease in antiphospholipid syndrome.
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. However, none of these medications is recommended for use during pregnancy or breast-feeding.
Rituximab (Rituxan). This drug has been used successfully to treat conditions affecting the function of the immune system. But there isn't enough evidence of benefit to recommend rituximab as a treatment for antiphospholipid syndrome.
Depending on your treatment plan for antiphospholipid syndrome, there are additional steps you can take to protect your health.
If you take anticoagulants
If your antiphospholipid syndrome requires that you take anticoagulant medication, take extra precautions to keep from injuring yourself and to avoid bleeding. Follow these suggestions:
Avoid contact sports or other activities that could cause bruising or injury or cause you to fall.
Use a softer toothbrush and waxed floss.
Shave with an electric razor.
Take extra care when using knives, scissors and other sharp tools.
Certain foods and medications may affect how well your anticoagulants work. Ask your doctor for guidance about:
Safe dietary choices. Vitamin K can lessen the effectiveness of warfarin. It's important to be consistent in how much vitamin K you get daily. The average daily value of vitamin K for adult men is 120 micrograms (mcg). For adult women, it's 90 mcg. While eating small amounts of foods that are rich in vitamin K may not be harmful, avoid eating large amounts of kale, spinach, lettuce, broccoli, Brussels sprouts, parsley, collard greens, mustard greens and soybeans.
On the other hand, cranberry juice and alcohol may dangerously increase warfarin's blood-thinning effect. Ask your doctor if you need to limit or avoid these drinks.
Safe medications and dietary supplements. Certain medications, vitamins and herbal products may interact dangerously with warfarin. These may include over-the-counter pain relievers, cold medicines, stomach remedies or multivitamins, as well as garlic, ginkgo and green tea products.
If you don't take anticoagulants
If you have antiphospholipid antibodies but do not take anticoagulant medication, take these precautions:
Tell your doctor that you have antiphospholipid antibodies.
Ask your health care provider to take measures to help prevent deep vein thrombosis if you can't move due to surgery or other medical reasons.
Take steps, such as lowering your cholesterol level, to help prevent a heart attack or stroke.