Cardiolipin antibody


Alternative names, keywords


Samples required

Clotted blood (gold cap, 5 mL tube). Smaller tubes are available for paediatric samples.

Test indications

Cardiolipin antibody has a disease association with the anti-phospholipid syndrome (APLS). The main features of this disease are thrombosis and/or recurrent fetal loss. Other features may include livedo reticularis, thrombocytopaenia, heart valve disease, nephropathy and neurological disease.

The diagnosis is suggested by strong positive IgG or IgM cardiolipin antibody in association with appropriate clinical features; however, it should be noted that IgM cardiolipin probably has far lower predictive value compared to IgG. A repeat sample should be sent after 12 weeks for confirmation, as transient positives may occur during infection or inflammation.

Test information

Samples are analysed by immunoassay for both IgG and IgM cardiolipin antibody.

Beta-2 glycoprotein-1 antibody is another anti-phospholipid antibody that can be useful in some situations. This test is referred to an external laboratory for analysis.

Reference range

Cardiolipin IgG and IgM antibody:

< 20 negative
20 or greater positive

Turnaround time

14 days.