What are antiphospholipids & anticardiolipins?

by Carolyn Salafia, MD, Ph.D.

They are antibodies that have been associated with systemic disease and with pregnancy loss. Normally, antibodies are produced by your immune system to fight infectious disease. They can also be produced in the process of rejecting a transplanted organ or skin that's grafted on the surface of the body. You continually acquire the ability to make new antibodies and, over time, you may develop antibodies to your own tissues or cells. Some people develop antibodies to molecules that are called phospholipids. These antibodies are called antiphospholipids. There are many types of antiphospholipids and anticardiolipins were the first type to be linked with pregnancy loss.

Phospholipids are fatty molecules on cell membranes that help maintain the proper balance between bleeding and clotting. (All normal, healthy people continually make blood clots and then break them down.) If antibodies block the phospholipids from being able to bind to their necessary sites of activity, the phospholipids will no longer be available to help regulate the balance of blood flow and clotting. As a result, blood clots may form anywhere in your body. If blood clots form in your brain, you might have mini-strokes. If blood clots travel to your heart, you may have a heart attack. If blood clots form in the blood vessels of the placenta, the fetus will be deprived of oxygen and nutrients. If the placental injury caused by the clots is mild, it will lead to growth retardation. If severe, it will lead to the loss of the pregnancy.

Many women with these antibodies may be asymptomatic until they suffer recurrent pregnancy loss. However, it is very important to note that many women with phospholipid antibodies never have a problem with pregnancy. There have been many cases of women with horrible systemic disease who gave birth to numerous healthy children. This is a condition where blind men feeling the elephant is extremely important to keep in mind. Obstetricians test for phospholipid antibodies only in women who have reproductive loss. It can be easy for an obstetrician to forget that many women who have these antibodies never have a problem in pregnancy. If you do have these antibodies your doctor cannot automatically assume they are the cause for your pregnancy losses or that anticoagulation is your best treatment. Tissue or slides from your previous losses should be examined by a perinatal pathologist to determine whether these antibodies did indeed contribute to your pregnancy loss, or whether some other reason might be causing or contributing to it. This other reason would need to be treated as well in order to ensure your next pregnancy the best chance of success.

You may be screened for many different types of antiphospholipids. It's important for you to know there's some controversy about whether all the antiphospholipids that are being tested for are actually associated with pregnancy loss and how they're associated with loss. Also, there are problems with testing for many different types of antiphospholipids because the more types you test for, the greater the chance that a person will be positive or borderline for one of them by random chance alone. This borderline or positive finding may be clinically meaningless. If this is the case for you, then your physician may wrongly assume that antiphospholipids are causing your losses when, in fact, some other reason might be. Again, a perinatal pathologist can help determine that reason.

If phospholipid antibodies are responsible for your pregnancy losses, a perinatal pathologist can help determine the proper course of treatment. Phospholipid antibodies can cause different types of injuries in the placenta and the only way to tell the pattern of injury is to examine placental tissue under a microscope. Some women will mainly show placental injury caused by bloodclots in the mother's blood vessels. For these women the standard method of anti-coagulant treatment (generally baby aspirin and heparin) will be effective in helping to maintain their next pregnancies. Some women have very little evidence of clotting at all and have primarily chronic inflammatory changes. That is the type of placental injury I've very commonly seen under the microscope in patients with phospholipid antibodies who've had losses after anti-coagulant therapy. Many doctors I know have tried intravenous gammagobulin on those patients with some success but we haven't been able to accumulate enough cases yet to specify the degree of success.

Carolyn Salafia, M.D., Ph.D., is board certified in Anatomic and Clinical Pathology and in Pediatric Pathology. 

Note: This communication is for educational purposes only and should not be used as a substitute for a consultation with your physician.