Antiphospholipid (AN-te-fos-fo-LIP-id) syndrome occurs when your immune system mistakenly creates antibodies that make your blood much more likely to clot. Antiphospholipid syndrome (APS) is an autoimmune syndrome caused by antiphospholipid antibodies. These antibodies are often referred to by different terms, including anticardiolipin antibody, lupus anticoagulant, and antiphospholipid antibody. APS can be primary or secondary, and also can be referred to by the name Hughes syndrome or “sticky blood”.
This can cause dangerous blood clots in the legs, kidneys, lungs, and brain. In pregnant women, the antiphospholipid syndrome also can result in miscarriage and stillbirth.
Antiphospholipid syndrome (APS) is an autoimmune disorder. Signs and symptoms vary but may include blood clots, miscarriage, rash, chronic headaches, dementia, and seizures.[1] APS occurs when your body’s immune system makes antibodies that attack phospholipids. Phospholipids are a type of fat found in all living cells, including blood cells and the lining of blood vessels. Most cases of APS occur in people with no family history of the disorder, however, there are rare cases of APS clustering in a family. A widely accepted explanation for APS is that it is caused by a combination of gene mutations (making one more susceptible to APS) and environmental exposure (such as to a virus). Currently, there is not a cure for APS. The goal of treatment is to prevent blood clots from forming and to keep existing clots from getting larger.[2][3][4]
Causes
The antiphospholipid syndrome occurs when your immune system mistakenly produces antibodies that make your blood much more likely to clot. Antibodies normally protect the body against invaders, such as viruses and bacteria.
Antiphospholipid syndrome can be caused by an underlying condition, such as an autoimmune disorder, infection or certain medications. You also can develop the syndrome without an underlying cause.
Risk factors for antiphospholipid syndrome include:
- Your sex. This condition is much more common in women than in men.
- Immune system disorders. Having another autoimmune condition, such as lupus or Sjogren’s syndrome, increases your risk of antiphospholipid syndrome.
- Infections. This condition is more common in people who have certain infections, such as syphilis, HIV/AIDS, hepatitis C or Lyme disease.
- Medications. Certain medications have been linked to antiphospholipid syndrome. They include hydralazine for high blood pressure, the heart rhythm-regulating medication quinidine, the anti-seizure medication phenytoin (Dilantin) and the antibiotic amoxicillin.
- Family history. This condition sometimes runs in families.
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
Symptoms
Signs and symptoms of antiphospholipid syndrome can include:
- Blood clots in your legs (DVT). Signs of a DVT include pain, swelling and redness. These clots can travel to your lungs (pulmonary embolism).
- Repeated miscarriages or stillbirths. Other complications of pregnancy include dangerously high blood pressure (preeclampsia) and premature delivery.
- Stroke. A stroke can occur in a young person who has antiphospholipid syndrome but no known risk factors for cardiovascular diseases.
- 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 red rash with a lacy, net-like pattern.
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. This can cause 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.
This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.
| Medical Terms | Other Names |
Learn More:
HPO ID
|
|---|---|---|
| Percent of people who have these symptoms is not available through HPO | ||
| Arterial thrombosis |
Blood clot in artery
|
0004420 |
| Autoimmune thrombocytopenia | 0001973 | |
| Autosomal dominant inheritance | 0000006 | |
| Blurred vision | 0000622 | |
| Central retinal artery occlusion | 0025342 | |
| Iritis |
Inflammation of iris
|
0001101 |
| Keratitis |
Corneal inflammation
|
0000491 |
| Lupus anticoagulant | 0025343 | |
| Retinal detachment |
Detached retina
|
0000541 |
| Retinal vasculitis | 0025188 | |
| Scleritis | 0100532 | |
| Venous thrombosis |
Blood clot in vein
|
0004936 |
| Visual loss |
Loss of vision
[ more ] |
0000572 |
| Vitritis | 0011531 | |
When to see a doctor
Contact your doctor if you have unexplained bleeding from your nose or gums; an unusually heavy menstrual period; vomit that is bright red or looks like coffee grounds; black, tarry stool or bright red stool; or unexplained abdominal pain.
Seek emergency care if you have signs and symptoms of:
- Stroke. A clot in your brain can cause sudden numbness, weakness or paralysis of your face, arm or leg. You may have difficulty speaking or understanding speech, visual disturbances and a severe headache.
- Pulmonary embolism. If a clot lodges in your lung, you may experience sudden shortness of breath, chest pain and coughing up blood-streaked mucus.
- Deep vein thrombosis (DVT). Signs and symptoms of DVTs include swelling, redness or pain in a leg or arm.
Diagnosis
A diagnosis of antiphospholipid syndrome is made based upon a thorough clinical evaluation, a detailed patient history, identification of characteristic physical findings (at least one blood clot or clinical finding), and a variety of tests including simple blood tests.
The most common blood tests used to detect antiphospholipid antibodies are anticardiolipin antibody immunoassays (which, despite the name, detect mainly antibodies to beta-2-glycoprotein I), anti-beta-2-glycoprotein antibody immunoassays, and lupus anticoagulant tests (coagulation assays that detect subsets of anti-beta-2-glycoprotein I antibodies and anti-prothrombin antibodies). Positive tests should be repeated because antiphospholipid antibodies can be present in short intervals (transiently) due to other reasons such as infection or drug use. Borderline negative tests may need to be repeated because individuals with APS have initially tested negative for the antiphospholipid antibodies.
Treatment
Individuals with APS who do not have symptoms may not require treatment. Some individuals may undergo preventative (prophylaxis) therapy to avoid blood clots from forming. For many individuals, daily treatment with aspirin (which thin the bloods and prevents blood clots) may be all that is needed.
Individuals with a history of thrombosis may be treated with drugs that preventing clotting by thinning the blood. These drugs are often referred to as anticoagulants and may include heparin and warfarin (Coumadin). New oral blood thinners (dabigatran, rivaroxaban, and apixaban) have recently been approved to treat other blood clotting conditions. Studies are needed to determine whether these drugs are appropriate for preventing recurrent blood clots in patients with APS. Individuals with repeated thrombotic events may require lifelong anticoagulant therapy.
Importantly, affected individuals are strongly encouraged to avoid or reduce risk factors that increase the risk of a blood clot forming. Such risks include smoking, the use of oral contraceptives, high blood pressure (hypertension), or diabetes. During pregnancy, women at a high risk for pregnancy loss are treated with heparin, sometimes in combination with low dose aspirin.
In some cases, heart valve damage may be severe and require surgical replacement.
Vascular events
Acute thrombotic events are treated with anticoagulants (blood thinners), initially with intravenous heparin and then followed by oral warfarin (Coumadin). In serious situations, some patients also are given compounds that dissolve clots quickly.
In patients with aPL, oral anticoagulation is required to avoid recurrences of venous blood clots, possibly over a period of years. For arterial events, recurrences also are prevented with drugs that inhibit platelets, such as aspirin and clopidogrel (Plavix).
Pregnancy-related events
Subcutaneous (under the skin) injections of heparin and low-dose aspirin are the standard therapy for preventing miscarriages. The therapy is started at the beginning of the pregnancy and continued in the period immediately after the delivery. This therapeutic approach has been shown to be effective in the majority of the cases, with the delivery of healthy babies. In more difficult cases, additional therapies such as intravenous immunoglobulin (IVIG) infusions and administration of corticosteroids (prednisone) may help.
Pregnant women who had previous blood clots may receive the same combination of heparin and low-dose aspirin – but with higher doses of heparin – because of the increased risk of blood clots. The therapy with heparin and aspirin has been shown to be safe for both the mother and the baby. When antibodies are detected in patients with no prior thrombotic events or miscarriages, the need for preventive therapy must be evaluated case by case. However, it is generally accepted that treatment is not necessary if no additional risk factors for clotting or an associated systemic autoimmune disease (e.g. Lupus) are present.
Complications
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.
- 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. Another possible complication is heart damage.
- Lung problems. These can include high blood pressure in your lungs and pulmonary embolism.
- Pregnancy complications. These can include miscarriages, stillbirths, premature delivery, slow fetal growth and dangerously high blood pressure during pregnancy (preeclampsia).
Rarely, a person can have repeated clotting events in a short time, leading to progressive damage in multiple organs.
References
