Coordinated Health


Lupus anticoagulants are antibodies against substances in the lining of cells. These substances prevent blood clotting in a test tube. They are called phospholipids.

Persons with these antibodies may have an abnormally high risk of blood clotting.

Causes, incidence, and risk factors

Most often lupus anticoagulants are found in persons with diseases such as systemic lupus erythematosus (SLE).

Lupus anticoagulants may also occur if:

  • You take certain medicines, such as phenothiazines, phenytoin, hydralazine, quinine, and the antibiotic amoxicillin.

You have such conditions such as

  • Inflammatory bowel disease (Crohn’s disease and ulcerative colitis), infections, and certain kinds of tumors.

Some people have no risk factors for this condition.


You may not have any symptoms. Symptoms that may occur include:

  • Blood clots in the legs or the lungs as well as stroke or heart attack
  • Recurrent miscarriages

Signs and tests

The following tests may be done:

  • Partial thromboplastin time (PTT)
  • Russell viper venom time
  • Thromboplastin inhibition test


Often, you will not need treatment if you do not have symptoms or if you have never had a blood clot in the past.

Take the following steps to help prevent blood clots from forming:

  • Avoid most birth control pills or hormone treatments for menopause (women).
  • Do not smoke or use other tobacco products.
  • Get up and move around during long plane flights or other times when you have to sit or lie down for extended periods.
  • movie your ankles up and down when you can’t move around.

Your doctor  may prescribe blood thinning medicines (such as heparin and warfarin) to help prevent blood clots:

  •  After surgery
  • After a bone fracture
  • With active cancer
  • When you need to set or lie down for long periods of time, such as during a hospital stay or recovering at home.

You may also need to take blood thinners for 3-4 weeks after surgery to lower your risk of blood clots.

Expectations (prognosis)

Most of the time, outcome is good with proper treatment. Some people may have blood clots that are hard to control with treatments. Symptoms may recur.

Calling your health care provider

Call your health care provider if you notice symptoms of a blood clot such as:

  • Swelling or redness in the leg
  • Shortness of breath
  • Pain, numbness and pale skin color in an arm or leg.