Cardiolipin antibodies (IgG, IgM, IgA), anticardiolipin, aCL antibody
A cardiolipin antibodies test looks for a certain kind of antibody in your blood. An antibody is a substance in your blood that helps fight off infection. The antibodies attack cardiolipins by mistake. Cardiolipin is a phospholipid, or a kind of fat in the blood that is important for blood clotting. When the antibodies attack cardiolipin, blood clots can occur. Platelets, blood cells that help blood to clot, also get used up, leading to problems with bleeding. The levels of these antibodies are often high in people with abnormal blood clotting, autoimmune diseases like systemic lupus erythematosus (SLE), or repeated miscarriages.
You may need this test if you often have abnormal blood clotting or abnormal bleeding. If you have had frequent miscarriages, the test might help healthcare providers figure out why. Also people with some autoimmune diseases such as SLE have cardiolipin antibodies in their blood. This test may be used to help diagnose this disease. When high levels of cardiolipin antibodies are found in people with these or other issues, it is known as cardiolipin antibody syndrome. This test helps diagnose this condition.
The cardiolipin antibodies test is usually just one of many tests that may be done to check why you are having your symptoms. The tests you get will depend on what your healthcare provider is looking for. For example, if your healthcare provider thinks you have SLE, you will probably need other blood tests. You may also need imaging tests and tissue biopsies.
These other tests may include:
Complete blood cell count
Partial thromboplastin time and activated prothromboplastin time. These tests see how your blood clots.
Antinuclear antibody test. These antibodies are found in people with lupus.
Antiphospholipid antibody test. These antibodies are found in people with abnormal blood clots.
Ultrasound, to look for clots in your arteries or veins
Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you.
The results of a cardiolipin antibody test are easy to understand. If you're negative for cardiolipin antibodies, that is normal. If you're positive, you might have cardiolipin antibody syndrome. You will probably be retested to see if the antibody stays in your blood. You may need to wait as long as 12 weeks between each test period.
The test is done with a blood sample. A needle is used to draw blood from a vein in your arm or hand.
Having a blood test with a needle carries some risks. These include bleeding, infection, bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may feel a slight sting or pain. Afterward, the site may be sore.
Although cardiolipin antibodies are commonly related to SLE, a positive test for them doesn't mean you have it. Other tests will be needed to confirm the diagnosis. When you have problems related to blood clotting, miscarriages, or other issues, this test result can help healthcare providers figure out the best way to treat your condition.
You don't need to prepare for this test.