Anti-phospholipid antibodies


Alternative names, keywords

Cardiolipin antibody, B2GP1 antibody, beta 2 glycoprotein 1 antibody, APLA.

Samples required

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

Test indications

Investigation of anti-phospholipid syndrome, which is associated with thrombosis and recurrent fetal loss.

Test information

A panel of tests for IgG and IgM cardiolipin AND B2GP1 antibodies. Positives are relatively common in the healthy population; positive results are not diagnostic, and results should be interpreted in clinical context.

Positive results may be confirmed with a second test at least 12 weeks later. Further repeats are not needed.

Negative results do not need to be repeated routinely.

For suitable patients, consider lupus anticoagulant test in addition (performed in Haematology).

Method: Phadia 250 ELIA

Reference range


   Negative   Equivocal   Positive 

IgG cardiolipin 

 <10 GPL units/mL 

10 - 40  40 or more 

IgM cardiolipin 

 <10MPL units/mL  10 - 40   40 or more 


 < 7 U/mL  7 - 10  10 or more 


 < 7 U/mL  7 - 10  10 or more 

Turnaround time

10 days.