What are lupus anticoagulants?
Lupus anticoagulants (LAs) are a type of antibody produced by your body’s immune system. While most antibodies attack disease in the body, LAs attack healthy cells and cell proteins.
They attack phospholipids, which are essential components of cell membranes. LAs are associated with an immune system disorder known as antiphospholipid syndrome.
LAs can increase the risk of blood clots. However, antibodies can be present and not lead to a clot.
If you develop a blood clot in one of your arms or legs, symptoms may include:
- swelling in your arm or leg
- redness or discoloration in your arm or leg
- breathing difficulties
- pain or numbness in your arm or leg
A blood clot in the area of your heart or lungs may cause:
- chest pain
- excessive sweating
- breathing difficulties
- fatigue, dizziness, or both
Blood clots in your stomach or kidneys may lead to:
- belly pain
- thigh pain
- diarrhea or bloody stool
Blood clots can be life-threatening if they aren’t treated promptly.
Small blood clots caused by LAs can complicate a pregnancy and induce miscarriage. Multiple miscarriages may be a sign of LAs, especially if they occur after the first trimester.
Roughly half of people with the autoimmune disease lupus also have LAs.
Your doctor may order testing for LAs if you have unexplained blood clots or have had multiple miscarriages.
No single test helps doctors conclusively diagnose LAs. Multiple blood tests are required to determine if LAs are present in your bloodstream. Repeat testing is also needed over time to confirm their presence. This is because these antibodies can appear with infections, but go away once the infection resolves.
Tests may include:
The partial thromboplastin time (PTT) test measures the time it takes your blood to clot. It can also reveal if your blood contains anticoagulant antibodies. However, it won’t reveal whether you specifically have LAs.
If your test results indicate the presence of anticoagulant antibodies, you’ll need to be retested. Retesting normally happens in about 12 weeks.
Other blood tests
If your PTT test indicates the presence of anticoagulant antibodies, your doctor may order other types of blood tests to look for signs of other medical conditions. Such tests may include:
- anticardiolipin antibody test
- kaolin clotting time
- coagulation factor assays
- dilute Russell viper venom test (DRVVT)
- LA-sensitive PTT
- beta-2 glycoprotein 1 antibody test
These are all blood tests that carry little risk. You may feel a brief sting when the needle pierces your skin. It may feel a bit sore afterward as well. There’s also a slight risk of infection or bleeding, as with any blood test.
Not everyone who receives a diagnosis of LAs requires treatment. If you don’t have symptoms and you haven’t had blood clots before, your doctor may prescribe no treatment for the time being, as long as you’re feeling well.
Treatment plans will differ from individual to individual.
Medical treatments for LAs include:
These medications help prevent blood clots by suppressing your liver’s production of vitamin K, which facilitates blood clotting. Common blood thinners include heparin and warfarin. Your doctor may also prescribe aspirin. This drug inhibits platelet function instead of suppressing vitamin K production.
If your doctor prescribes blood thinners, your blood will be periodically tested for the presence of cardiolipin and beta-2 glycoprotein 1 antibodies. If your test results show that the antibodies are gone, you might be able to discontinue your medication. However, this should only be done with consultation with your physician.
Some people with LAs only need to take blood thinners for a number of months. Other people need to stay on their medication for the long term.
Steroids, such as prednisone and cortisone, can inhibit your immune system’s production of LA antibodies.
Plasma exchange is a process in which a machine separates your blood plasma — which contains the LAs — from your other blood cells. The plasma that contains the LAs is replaced by plasma, or a plasma substitute, that’s free of the antibodies. This process is also called plasmapheresis.
Discontinuing other medications
Some common medications can potentially cause LA. These medications include:
Talk to your doctor about any medication you’re taking to determine if it could be causing LAs. If you are, you and your doctor can discuss whether it’s safe for you to discontinue use.
There are simple lifestyle changes you can make that may also help you manage LAs, whether or not you’re taking medication for your condition. These include:
Getting regular exercise
Exercise and movement increases blood flow. This means it also helps prevent blood clotting. Find your favorite way of getting exercise and do it regularly. It doesn’t have to be strenuous. Simply taking a good brisk walk each day can stimulate blood flow.
Quit smoking and moderate your drinking
Quitting smoking is very important if you have LAs. Nicotine causes your blood vessels to contract, which leads to clotting.
Fat cells produce substances that may prevent blood clots from dissolving like they’re supposed to. If you’re overweight, your bloodstream may carry too many of these substances.
Reduce your intake of vitamin K-rich foods
Many foods that contain a lot of vitamin K are good for you otherwise, but they help create blood clots.
If you’re on blood thinners, eating foods high in vitamin K is counterproductive to your therapy. Foods that are rich in vitamin K include:
In most cases, both blood clotting and symptoms of LAs can be controlled with treatment.
According to a 2002 review, women who are treated for antiphospholipid syndrome — usually with low-dose aspirin and heparin — have about a 70 percent chance of carrying a successful pregnancy to term.