Antiphospholipid antibody syndrome (APS) causes blood clots in the veins or arteries, miscarriages and other problems. The condition can affect any organ, including the lungs, brain, liver, kidneys, eyes, heart and skin. Women with the syndrome can have repeated miscarriages or late-term death of the fetus.

APS probably involves the immune system, although no one knows its exact cause. People with APS have antibodies that interact with proteins in the blood and cause the blood to clot more than normal. Antibodies are molecules produced by the immune system that normally fight infection. Having antiphospholipid antibodies does not necessarily mean that someone will develop symptoms. Up to 8% of normal people without any evidence of APS have the antibodies.

There are two types of APS: primary and secondary. People with primary APS do not have any associated condition. The secondary form is associated with another immune disorder, such as lupus (systemic lupus erythematosus), or with a viral infection. Some doctors believe a medication causes secondary APS. The most common suspect is chlorpromazine (Thorazine). A brief form of secondary APS occurs commonly in children after a viral infection.

The symptoms of APS can include any of the following:

• Nervous system – APS can cause stroke; involuntary jerking movements of the arms or legs (chorea); dementia; migraines and other problems of the nervous system. Stroke symptoms include slurred speech or difficulty understanding or forming words, change in vision or weakness on one side of the body. In a form of APS called Sneddon's syndrome, people have repeated strokes and a mottling of the skin that is lacy purple and white, called livedo reticularis. Some people with APS develop a syndrome similar to multiple sclerosis. They can have numbness, double vision and difficulty walking or urinating.



• Heart and blood vessels – APS can lead to heart attacks, heart valve problems that can mimic bacterial endocarditis, and clots in the upper chambers of the heart. Up to 20% of younger people who have a heart attack have antiphospholipid antibodies. Clots in the veins can cause inflammation of the veins (thrombophlebitis) of the legs with pain in the thigh or calf, swelling of the leg, and sometimes a visible, red, thickened blood vessel.



• Blood cells – Up to one in four people with a condition called idiopathic thrombocytopenic purpura (ITP) have antiphospholipid antibodies. Over time, many of these people develop APS. Idiopathic thrombocytopenic purpura is characterized by a low number of platelets. Because platelets are blood cells that help the blood to clot, people with ITP may be prone to bleeding even though APS tends to promote clotting. People with ITP and APS can have problems with excessive clotting and excessive bleeding. Also, red blood cells can break down abnormally, causing fatigue, dizziness and pale skin, but this is more common in people with lupus.



• Lung – Blood clots in the lung can cause chest pain, shortness of breath and rapid breathing. Repeated clots can cause elevated pressure in the blood vessels around the lungs (pulmonary hypertension), which may cause the person to be constantly short of breath.



• Gastrointestinal – APS can affect the blood supply to the intestines, causing abdominal pain, fever and blood in the stool. APS can cause a condition called Budd-Chiari syndrome, in which a blood clot prevents blood from flowing out of the liver, and the person may experience nausea, vomiting, jaundice (yellow skin) dark urine, pale stool and swelling of the abdomen.



• Kidneys – Blood clots that affect the kidneys can cause kidney damage and blood in the urine.



• Skin – APS can cause purple and white mottling of the skin, and repeated sores (ulcers) and bumps (nodules) of the skin. It can cause tissue in the fingertips to die (gangrene).



• Eyes – Veins or arteries in the retina can be affected, causing blurring or loss of vision.



• Pregnancy – APS can cause problems for the fetus, such as miscarriage, a partial or complete separation of the placenta from the uterus before the baby is born (placental abruption) and a small placenta. It can cause problems for the pregnant woman, such as stroke or blood clots in the lungs. APS may be associated with a syndrome of pregnancy known as HELLP: hemolysis (breakdown of red blood cells), elevated liver tests and low platelets.

Many symptoms that occur with APS are common and do not necessarily mean APS is the cause. However, when blood clots or miscarriages occur for no apparent reason, or when a young person has a heart attack or stroke, the doctor may order tests to detect the antibodies associated with APS.

People with antiphospholipid antibodies may have a positive screening test for syphilis even though they do not have the disease. Fortunately, confirmatory tests are available to rule out syphilis infection in a person with antiphospholipid antibodies.

Although some people with APS continue to have symptoms off and on throughout their lives, others improve without any repeat episodes. Some people even lose the antibodies associated with the syndrome. This can happen with primary APS, but it is especially common after a viral infection, in women who recently were pregnant, or when a medication suspected to be associated with APS is no longer used.

Because no one knows what causes APS, there is no way to prevent it. However, lifestyle changes can reduce the likelihood of blood clots. Quit smoking, increase physical activity and avoid medications suspected of increasing the risk of blood clots or causing APS.

If you have antiphospholipid antibodies but have not had blood clots or a miscarriage, your doctor may recommend that you take a low-dose aspirin every day. However, aspirin increases the risks of bleeding, so your doctor will have to determine whether the uncertain benefits are worth the risks for you.

For people with a history of blood clots, doctors usually prescribe a powerful blood thinner called warfarin (Coumadin), which usually is taken for life. People who take warfarin need to have their blood tested regularly because if the blood is too thin, the risk of bleeding increases, and if it is not thin enough, clotting is more likely.

Another blood thinner called heparin (sold under several brand names) may be used before you start taking warfarin. Heparin also is used for pregnant women, because warfarin is not safe for the developing fetus. Heparin is given as an injection.

A woman with APS who is trying to become pregnant after repeated miscarriages may increase the chance of a successful pregnancy if she starts getting heparin injections and taking low-dose aspirin. This treatment starts as soon as the pregnancy is discovered and continues until just before delivery. For this purpose, a different form of heparin called enoxaparin (Lovenox) sometimes is used.

Other medications used in advanced cases of APS include steroids, immune-suppressing drugs and antiglobulin medications. However, the benefits of these medications have not been proven, and they can cause significant side effects. They are used only for people who do not respond well to blood thinners.

Contact a doctor if you have any symptoms of APS. Call your doctor if you have APS and want to become pregnant, or if you have unusual bruising, bleeding or other symptoms of APS.

People with primary APS generally lead normal, healthy lives with the help of medication and lifestyle changes. However, some people will have repeated blood clots despite the best treatments (a condition called catastrophic antiphospholipid antibody syndrome).

People with secondary APS generally have a similar prognosis, but their illnesses and life spans can be affected by associated conditions.

American College of Rheumatology
1800 Century Place
Suite 250
Atlanta, GA 30345-4300
Phone: 404-633-3777
http://www.rheumatology.org/

National Institute of Arthritis and Musculoskeletal and Skin Diseases
Information Clearinghouse
National Insitutes of Health
1 AMS Circle
Bethesda, MD 20892-3675
Phone: 301-495-4484
Toll-Free: 1-877-226-4267
TTY: 301-565-2966
Email: niamsinfo@mail.nih.gov
http://www.niams.nih.gov/

National Organization for Rare Disorders (NORD)
55 Kenosia Ave.
P.O. Box 1968
Danbury, CT 06813-1968
Phone: 203-744-0100
Toll-Free: 1-800-999-6673
TTY: 203-797-9590
Email: orphan@rarediseases.org
http://www.rarediseases.org/