Cardiolipins are a type of Phospholipid, a fat in the blood, that plays an important role in blood clotting.  In some people with autoimmune disorders such as Lupus, the body produces antibodies to target its own Cardiolipins.  Cardiolipin Antibodies are associated with the development of abnormal blood clots and have been linked to recurrent miscarriages in pregnant women.  These antibodies can develop at any time in people with autoimmune disorders so periodic testing may be necessary.  Blood testing for Cardiolipin Antibodies can help determine the cause of conditions associated with these antibodies and aid in the diagnosis of Antiphospholipid Syndrome (APS).  

- Anticardiolipins are antibodies produced by the immune system against the platelet membrane phospholipids responsible for the coagulation of blood clots. 

- Anticardiolipin antibodies are often responsible (with lupus anticoagulants and beta-2 glycoprotein antibodies) for the abnormal formation of clots in veins (phlebitis) and arteries (arterial thrombosis). 

- They are involved in antiphospholipid syndrome, which occurs, for example, through repeated miscarriages during the second or third trimester of pregnancy. 

There are three types of anticardiolipin antibodies: IgG, IgA and IgM.

There are different classes (isotypes) of anticardiolipin antibody, namely IgG, IgM, and IgA. IgG is the anticardiolipin antibody type most associated with complications. An enzyme-linked immunosorbent assay (ELISA) is used to test for anticardiolipin antibodies. One can test for all isotypes at once, or they can be detected separately. High levels of the IgM isotype are associated with autoimmune hemolytic anemia, a condition in which an individual’s immune system attacks their red blood cells.