Antiphospholipid antibody syndrome

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at December 3, 2016
StartDiseasesAntiphospholipid antibody syndrome

Antiphospholipid antibody syndrome (APS) is a type of autoimmune disease that mistakenly creates antibodies that attack phospholipids in the body. This damages the blood cells in the body which can cause dangerous blood clots to develop. 


Definition & Facts

An autoimmune disorder is a condition in which the immune system attacks existing tissues or cells, producing antibodies to do so. Antiphospholipid antibody syndrome is a type of autoimmune disorder which attacks phospholipids, a type of fat that is stored in the body. Phospholipids are found in all living cells, including blood cells and blood vessels.

In an individual with APS, antibodies attack these cells and damage them, causing blood clots to potentially form in arteries and veins. Coagulation or blood clotting is a normal process, but in cases like these, the blood clots can block the blood's path and damage the body's organs.

APS is more commonly diagnosed in women and in people who have other autoimmune or rheumatic diseases. Antiphospholipid antibody syndrome is present in 15-20 percent of all cases of deep vein thrombosis and found in one third of all stroke victims under 50 years of age. Blood clots most often form in the lower legs, and those clots can break off and travel into the lungs causing a life-threatening pulmonary embolism.

Symptoms & Complaints

Some individuals with APS antibodies never experience any symptoms and live out their lives undiagnosed. Usually, a history of health problems helps identify this disorder as the cause of their health troubles. APS can lead to health problems like stroke, heart attack, kidney damage, deep vein thrombosis, pregnancy-related problems, pulmonary embolism, and more.

The pregnancy-related symptoms can include miscarriages or premature birth due to preeclampsia. People diagnosed with APS are also at risk for thrombocytopenia which is a condition where the blood in the patient has fewer platelets than needed. This can cause dangerous bleeding.

APS can be a fatal disease. Large blood clots can occur in the heart, lungs, or brain. People with APS can exhibit symptoms of the neurological variety, including chronic headaches, dementia, and seizures are possible if a blood clot has blocked the blood flow to an area of the brain.

A rash can develop from APS that is described as being a red, lacy, net-like pattern. Some patients with APS exhibit petechiae which is bleeding into the skin as shown by red patches and spots on the surface of the skin.


There are two types of antiphospholipid antibody syndrome: primary and secondary. Primary APS has no underlying reason for the disorder, like a pre-existing autoimmune disorder. Secondary APS is when the patient has an autoimmune disorder, like lupus, certain infections, or has taken certain medications, and APS results.

Medications that can heighten the risk of APS includes hydralazine for high blood pressure (hypertension), quinidine for cardiac arrhythmia, phenytoin to prevent seizures, and the antibiotic, amoxicillin.

There is a higher likelihood that relatives of people with antiphospholipid antibody syndrome will also have the antibodies present in their bodies. As mentioned above, it is possible to have the antibodies and exhibit no symptoms of the disorder. Below are listed a few situations and causes that may contribute to an individual developing the disorder if the antibodies are already present. 

Diagnosis & Tests

Different medical professionals may be utilized in this diagnosis, including a specialist in vascular diseases, obstetrics, or hematology depending on the patient's symptoms and complaints. The patient's medical history will be inquired about and a physical examination will be performed.

Blood tests are done to identify any unusual blood clotting and the presence of the antibodies. These blood tests look for lupus anticoagulant, anticardiolipin, and beta-2 glycoprotein I. If two of these listed antibodies appear in the blood at least twice, a diagnosis of antiphospholipid antibody syndrome can be confirmed. 

Treatment & Therapy

There is no cure for antiphospholipid antibody syndrome at this time, but medication can be prescribed to help stop blood clots from forming or to stop current ones from increasing in size.

If thrombosis is already present, blood thinners are usually prescribed to help. These can include heparin, warfarin, and aspirin. When taking anticoagulants, dosage should be monitored with blood tests to determine if the blood is clotting enough to stop the bleeding from a cut or bruise.

Treatment for APS during pregnancy is more complex and involves regular injections of medication. Heparin and aspiring can be recommended, but warfarin is not advised as it can cause birth defects. Treatment during pregnancy, while complicated, is usually effective in preventing an antiphospholipid antibody syndrome-related miscarriage.

Other types of treatment include statins, new blood thinners, and rituximab. Statins are medications that are generally used to lower cholesterol but may have a purpose in preventing blood clots as well. Dabigatran, rivaroxaban, and apixaban are oral blood thinners that could provide more treatment options for patients suffering from APS. None of these options are approved for pregnant women suffering from APS though.

Prevention & Prophylaxis

Complications of this disorder can be prevented with anticoagulants, regular checkups, and attention to dietary needs. Pregnant women require close monitoring and medications to ensure the health of the child and themselves. Women with this disorder must avoid estrogen replacement therapy.