Lupus Anticoagulant

This test is used to help evaluate a prolonged activated partial thromboplastin time (aPTT) and/or a clotting episode. It is also used to help determine the cause of recurrent miscarriages, especially in the 2nd and 3rd trimesters. It is also used as a part of an evaluation for antiphospholipid syndrome. This is not a diagnostic test for lupus.

Lupus anticoagulant is a protein that increases the risk of developing blood clots in both the veins and arteries. These clots may block blood flow in any part of the body, leading to strokes, heart attacks, pulmonary embolisms, deep vein thrombosis (usually clots in the legs), and to recurrent fetal loss, especially in the 2nd and 3rd trimesters (thought to be related to clotting in placental blood vessels). The lupus anticoagulant is an acquired, not inherited, condition. Although it is found most frequently in those with autoimmune diseases, such as Systemic Lupus Erythematosus (SLE) and HIV, the lupus anticoagulant may also be seen chronically or temporarily in those with infections or cancers and in those who are taking certain medications, such as phenothiazines, chlorpromazine, procainamide, and fansidar. It is thought to be present in about 1 – 2% of the general population, and may develop in people with no known risk factors.

The lupus anticoagulant (LA) is not a diagnostic test for lupus. It gets its name because it was first discovered to be associated with SLE.


No preparation or fasting is necessary unless you have been informed otherwise. A blood sample is obtained by inserting a needle into a vein in the arm.


  • Less than 23 GPL (IgG phospholipid units).

  • Less than 11 MPL (IgL phospholipid units).

Ranges for normal findings may vary among different laboratories and hospitals. You should always check with your doctor after having lab work or other tests done to discuss the meaning of your test results and whether your values are considered within normal limits.


Your caregiver will go over the test results with you and discuss the importance and meaning of your results, as well as treatment options and the need for additional tests if necessary.


It is your responsibility to obtain your test results. Ask the lab or department performing the test when and how you will get your results.