What is Beta2 Glycoprotein 1 - IgG?
Also Known As:
Anti-Beta-2 Glycoprotein 1, ?2-Glycoprotein 1 Antibodies, Beta 2GP1 Ab
Beta-2 Glycoprotein 1 Antibodies IgG, IgM and IgA
Beta-2 glycoprotein 1 antibody is an autoantibody that is associated with inappropriate blood clotting. This test detects and measures beta-2 glycoprotein 1 antibodies in the blood.
Beta-2 glycoprotein antibody is considered one of the primary autoantibodies called antiphospholipid antibodies that mistakenly target the body’s own lipid-proteins (phospholipids) found in the outermost layer of cells (cell membranes) and platelets. This test is often ordered along with tests for other antiphospholipid antibodies, including cardiolipin antibody and lupus anticoagulant.
Antiphospholipid antibodies interfere with the body’s blood clotting process in a way that is not fully understood yet. They increase the risk of developing inappropriate blood clots (thrombi) in both arteries and veins.
Antiphospholipid antibodies most frequently develop in people with the autoimmune disorder called antiphospholipid syndrome (APS). This condition is associated with widespread blood clots (thrombotic episodes), a low platelet count (thrombocytopenia), or pregnancy complications such as pre-eclampsia and recurrent miscarriages, especially in the second and third trimesters.
Also, some people with autoimmune disorders such as lupus (systemic lupus erythematosus, SLE) may begin to produce one or more of these autoantibodies, which can put them at risk of forming blood clots in blood vessels.
How is the test used?
Beta-2 glycoprotein 1 antibody tests are primarily used along with cardiolipin antibody and lupus anticoagulant testing to help diagnose:
- Antiphospholipid syndrome (APS)
- The cause of an unexplained blood clot (thrombotic episode)
- The cause of recurrent miscarriages in women
Sometimes the test may be used to determine whether you have developed these autoantibodies if you have another autoimmune disorder, such as lupus.
Laboratory tests can detect three different classes of these autoantibodies: IgG, IgM, and IgA. If the initial antiphospholipid antibody tests for the IgG and IgM classes are negative but APS is still strongly suspected, then the IgA class of these antibodies may be tested, along with other less common antiphospholipid antibodies, such as anti-phosphatidylserine and anti-prothrombin.
However, the value of testing for the IgA class of antiphospholipid antibodies remains controversial. According to the international consensus statement on APS, the presence of the IgA class (either anticardiolipin antibodies or beta-2 glycoprotein 1 antibodies) does not fulfill laboratory criteria for APS diagnosis.