Antiphosphatidylserine, IgG and IgM

Also known as: Phosphatidylserine/Prothrombin Antibody, (IgG and IgM), PS/PT Antibody (IgG and IgM)

Clinical Use

Use

This test can be used as an aid in the diagnosis of certain autoimmune thrombotic disorders, such as antiphospholipid syndrome (aPS). Antibodies to PS/PT correlate with the presence of lupus anticoagulants (LA), and this test may be useful in cases with difficult LA test interpretation. This assay also may assist in the determination of risk for thrombosis as well as obstetric complications in patients with antiphospholipid antibodies.

Special Instructions

Not provided.

Limitations

The pathogenic mechanism of aPS-PT antibody morbidity is substantially undefined, although under investigation. To date, aPS/PT antibodies are not included among the formal laboratory classification criteria for APS but are suggested as supplemental assays. The clinical significance of PS/PT IgG or IgM antibodies in diseases other than SLE or APS is currently under investigation. When negative PS/PT IgG or IgM titers are found in the presence of clinical indications, a lupus anticoagulant, anticardiolipin, anti-β2 or other additional testing is indicated. Diagnosis cannot be made on the basis of PS/PT IgG or IgM results alone. These results must be interpreted in conjunction with physical findings. Treatment must not be initiated on the basis of a positive PS/PT IgG or IgM titer alone. Supportive clinical indications must also be present. It is to be expected that some samples can be anticardiolipin positive and/or anti-β2 GPI positive yet PS/PT IgG or IgM negative. The anti-β2 GPI test is a specific marker of thrombotic risk. Patients with APS can be PS/PT positive yet lupus anticoagulant, anticardiolipin or anti-β2 negative.

Test Details