Orders for "Antiphospholipid Antibody"

The Clinical Laboratories frequently receive ambiguous orders for “antiphospholipid antibody” on the Miscellaneous Test requisitions (Form O-4). 

As a reminder, the standard laboratory diagnostic criteria for definite Anti-Phospholipid Syndrome (APS) include persistence of one of two positive antiphospholipid antibody screening tests for six or more weeks:

The common anti-phospholipid antibody screening tests are:

Cardiolipin Antibody, IgG and IgM, Serum

Cardiolipin Antibody, IgG, Serum

Cardiolipin Antibody, IgM, Serum

Lupus Anticoagulant, Citrated Whole Blood

The Immunopathology test requisition (MH06111) should be used for ordering IgG anti-cardiolipin antibody and IgM anti-cardiolipin antibody.  The Miscellaneous requisition should be used for ordering lupus anti-coagulants.

Additional clinically useful tests that are currently available in-house for evaluation of APS are the Anti-Beta-2-Glycoprotein I - IgG and IgM antibody tests.  Although these are not yet currently included among the standard diagnostic criteria for APS, recently published clinical investigations support their use. The Immunopathology Laboratory also performs these tests and they are listed on the Immunopathology test requisition (MH06111).

If we continue to receive ambiguous "anti-phospholipid antibody" requests as noted above, we will presume that these orders are for the purpose of evaluating patients for APS, and we will interpret them to be requests for both IgG and IgM anticardiolipin antibodies.

Additional information concerning tests for evaluation of APS is available in the Antiphospholipid Syndrome (APS): Laboratory Evaluation Appendix.

Questions may be directed to Dr. James Goeken (6-1966) or Dr. John Kemp (4-9611).