Antiphospholipid syndrome is an autoimmune disorder that can cause blood clots and miscarriages. Blood thinners work well to treat the syndrome and to help prevent future blood clots and miscarriages.
Antiphospholipid syndrome (also known as APS, antiphospholipid antibody syndrome or Hughes syndrome) is an autoimmune disorder in which your body’s immune system attacks proteins bound to phospholipids, a certain kind of fat found in all of the cells in your body. These antibodies make it much more likely that you will have blood clots in your arteries or veins, miscarriages and/or other pregnancy complications, such as preeclampsia.
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If you have antiphospholipid syndrome, your immune system makes abnormal proteins called antiphospholipid antibodies in your blood. When the antibodies attack your phospholipids, cells can get damaged. This damage can contribute to the formation of blood clots in your arteries and veins. The cause of increased risk of blood clots for people who have antiphospholipid antibodies is not straight-forward and there are likely multiple factors involved. Some people have antiphospholipid antibodies but never have signs or symptoms of the antiphospholipid syndrome.
Healthcare researchers believe that small blood clots get stuck in the placenta of individuals who are pregnant and have antiphospholipid syndrome. The blood clots block the flow of nutrients to the baby and can cause a miscarriage.
Antiphospholipid syndrome can affect anyone, but females are five times more likely to have antiphospholipid syndrome than males. Most individuals with antiphospholipid syndrome are diagnosed between the ages of 30 and 40.
While healthcare professionals and researchers don’t have exact numbers on the prevalence of the disorder, antiphospholipid syndrome is thought to be fairly common. Approximately 20% of people younger than 50 who have a stroke have antiphospholipid syndrome, and approximately 10% to 15% of individuals who experience recurrent miscarriages have antiphospholipid syndrome.
Symptoms and signs of antiphospholipid syndrome can include:
Antiphospholipid syndrome most commonly causes blood clots. The symptoms of having a blood clot depend on where the blood clot is in your body. Symptoms and signs of having blood clots can include:
It’s important to contact your healthcare provider immediately or go to the nearest hospital if you are experiencing signs and symptoms of a blood clot. Blood clots can be deadly.
Antiphospholipid syndrome is an autoimmune disorder. It develops when your body’s immune system mistakenly makes antibodies that attack phospholipid-binding proteins in your cells. Researchers are unsure what exactly causes your immune system to suddenly attack its own blood proteins, but healthcare professionals think it has to do with genetic mutations and environmental factors.
Antiphospholipid syndrome is diagnosed through more than one blood test that checks for antiphospholipid antibodies. This test is usually only taken by people with blood clots and/or individuals who are experiencing recurrent (frequent) miscarriages. Some people can have antiphospholipid antibodies and never experience a blood clot.
The screening for antiphospholipid syndrome requires three kinds of blood tests to check for antiphospholipid antibodies. Each individual test cannot find all of the possible antibodies, so the tests are often all used together. At least one of the three types of blood tests must be positive two different times three months or more apart in order for the person to be diagnosed with antiphospholipid syndrome.
Some people have antiphospholipid antibodies but never have signs or symptoms of the syndrome. Just because you have the antibodies doesn't mean that you have antiphospholipid syndrome. To be diagnosed with antiphospholipid syndrome (APS), you must have APS antibodies in addition to a history of health problems related to the disorder, such as blood clots and/or frequent miscarriages.
The main goal of treatment for antiphospholipid syndrome is to prevent further episodes of the medical conditions it is causing, whether that’s blood clots and/or miscarriages.
Blood thinners (anticoagulants) are generally used to prevent blood clots. Blood thinner medications that people with antiphospholipid syndrome may use include:
Individuals who have experienced recurrent miscarriages and who have been diagnosed with antiphospholipid syndrome may take the following medications to prevent another miscarriage and to deliver a healthy baby:
Taking blood thinners (anticoagulants) increases your chances of bleeding internally and externally. Your healthcare provider will check your dosage with blood tests to make sure your blood will be able to clot enough if you get a cut or a bruise.
It is important to know the warning signs of bleeding issues when you are taking blood thinners. Contact your healthcare provider right away if you experience any of the following symptoms:
The treatment therapy of heparin and low-dose aspirin for pregnant people who have antiphospholipid syndrome is safe and effective for both the parent and the baby.
There is currently no cure for antiphospholipid syndrome. However, treatment in the form of medication can help prevent the medical conditions antiphospholipid syndrome can cause, including blood clots and miscarriages.
While researchers aren’t sure what exactly causes antiphospholipid syndrome, the following things are considered risk factors for developing it:
If people with antiphospholipid syndrome are taking medication for the disorder and are maintaining their overall health, they can generally live healthy lives. Blood thinners work well to treat antiphospholipid syndrome and to prevent blood clots. However, you will need to see your healthcare provider regularly if you are on blood thinners to make sure your blood is still able to clot properly if you get a cut or bruise. Most people with antiphospholipid syndrome need to be on medication to treat it for the rest of their lives.
With proper treatment, pregnant individuals who have antiphospholipid syndrome are more likely to carry babies to term than those whose antiphospholipid syndrome isn't treated.
Antiphospholipid syndrome can be fatal. Death may occur as a result of dangerous blood clots in the heart, lungs or brain that are caused by antiphospholipid syndrome. If you have been diagnosed with antiphospholipid syndrome, it's important to take your medication regularly to prevent blood clots from forming in your body. Go to the nearest hospital as soon as possible if you are experiencing signs and symptoms of a blood clot.
In very rare cases, people with antiphospholipid syndrome develop blood clots in multiple veins or arteries throughout their body. This is called catastrophic antiphospholipid syndrome (CAPS). CAPS usually affects and causes damage to the kidneys, lungs, brain, heart and/or liver. It leads to death in over half of the people who have CAPS. Less than 1% of people who have antiphospholipid syndrome develop catastrophic antiphospholipid syndrome.
The main goal for managing antiphospholipid syndrome is preventing blood clots. Blood clots can largely be prevented through the use of blood thinner medication. However, there are several other conditions that can increase your risk of developing blood clots. If you have been diagnosed with antiphospholipid syndrome, it is essential to prevent, avoid or properly manage the following risk factors for developing blood clots if they apply to you:
If you are taking a blood thinner (anticoagulant) to treat antiphospholipid syndrome, you will need to see your healthcare provider routinely to make sure your dosage is working well.
Antiphospholipid syndrome can increase the risk of pregnancy-related complications such as preeclampsia. Talk with your healthcare provider about how to manage your antiphospholipid syndrome if you're pregnant or planning on becoming pregnant.
If you are experiencing symptoms and signs of having a blood clot or if you are on a blood thinner and are experiencing extensive bleeding, go to the nearest hospital as soon as possible.
Although part of the testing for APS is called “lupus anticoagulant”, your healthcare provider is not specifically testing for lupus when ordering tests for APS. Some people with lupus also have APS, which is where this term originated.
A note from Cleveland Clinic
Getting a diagnosis can be scary. Know that your healthcare team is there to help you and answer your questions. Antiphospholipid syndrome is very treatable. If you have had a blood clot or a miscarriage and have antiphospholipid syndrome, medication works well to help prevent them from happening again. Be sure to see your healthcare provider regularly to manage your antiphospholipid syndrome, and go to the nearest hospital if you are experiencing symptoms of a blood clot.
Last reviewed by a Cleveland Clinic medical professional on 08/19/2021.
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