Prothrombin Antibody (IgG)

Laboratory assay overview

This test is intended for the detection and semi-quantitation of IgG anti-prothrombin (aPT) antibodies. Antiphospholipid antibodies are a heterogenous group of antibodies that bind to protein-phospholipid complexes. aPT antibodies are included in this category and may be detected in patients with autoimmune diseases (e.g. systemic lupus erythematosus) and/or with antiphospholipid syndrome (APS). The aPT antibody concentration values obtained from this assay are an aid to diagnosis only. If the results from this test are negative, and the clinical history is suggestive of APS, suggest testing for the APS criteria antibodies - IgG and IgM beta-2-glycoprotein I and cardiolipin antibodies, and lupus anticoagulant. If the latter testing is positive, it is recommended to repeat testing in at least 12 weeks to demonstrate persistence of antibodies.