Tests for cardiolipin antibodies are frequently used to help determine the cause of:

·         An unexplained blood clot (thrombotic episode)

·         Recurrent miscarriages

·         A prolonged result on the coagulation (clotting test) PTT (partial thromboplastin time); in this setting, the test is often ordered along with lupus anticoagulant testing (e.g., dilute Russell viper venom test, DRVVT)

If cardiolipin antibodies are detected on an initial test, then it is usually repeated 12 weeks later to help determine whether their presence is persistent or temporary. If a person with a known autoimmune disorder tests negative for cardiolipin antibodies, they may be retested later as these antibodies may develop at any time in the future.

There are three classes of cardiolipin antibodies that may be present in the blood: IgGIgM and/or IgA. The two most commonly tested are IgG and IgM. However, if these tests are negative and clinical suspicions still exist, then IgA cardiolipin antibody testing may be ordered.

Some other tests that may be performed in conjunction with cardiolipin antibody tests include lupus anticoagulant testing (e.g., DRVVT) and anti-beta-2 glycoprotein 1 antibody.