Laboratory Medicine Program

Anti-cardiolipin Antibody
(ACA, antiphospholipid antibody)

Clinical Decription:
The Hematology Laboratory at UHN has introduced an expanded assay for the ACA to include IgG and IgM isotype titers, by ELISA assay. Relevance: Individuals with the antiphospholipid antibody syndrome (APS) have an increased risk for stroke, myocardial infarction, venous thrombosis, thromboembolism, thrombocytopenia, and/or recurrent miscarriages. Current international consensus for the serologic diagnosis of "antiphospholipid syndrome" is the presence of ACA of IgG and/or IgM isotype, at medium or high titer, on two or more occasions, at least six weeks apart. The presence of ACA of moderate to high titer for IgG is strongly associated with both arterial and venous thrombosis and recurrent pregnancy loss. IgM isotype is associated with venous thrombosis and both may be transient. ACA antibodies are quite common in the general population (5%-10%) and are not always associated with APS.
<br/><em>Biorad Bioplex 2200 package insert</em>

Method: Automated method; Bioplex 2200

Component Tests Used: ACA IgG and ACA IgM

Reference Ranges Used:
Negative <20 U/mL, Positive >=20 U/mL

Specimen Type: Citrated plasma
Collected In: 3.2% Sodium Citrate
Volume: 2.5 mL (minimum: 2.5 mL)

Shipping: Frozen at -20C

Special Instructions: Separate plasma from cells

Testing Schedule(s): Weekly.

Turnaround Time: 7-10 days

For more information, call 416.340.5227 or 1.866.865.5227