What it measures
Beta-2 glycoprotein I antibodies are a type of antiphospholipid antibody. They target a protein in the blood that binds to fats called phospholipids. The test usually reports IgG and IgM antibodies separately.
Why people test it
- Measured after an unexplained blood clot in a vein or artery.
- Checked after repeated miscarriages or some other pregnancy problems.
- Part of the antiphospholipid screen, with lupus anticoagulant and cardiolipin antibodies.
- A positive result is usually repeated at least 12 weeks later, as short-lived rises can follow infections.
Typical range
Results are given in units per millilitre, separately for IgG and IgM, with cut-offs that vary by lab and method. Your report shows the lab's own cut-offs.
Finger-prick or vein?
A finger-prick sample is often enough, as antibody tests need only a small amount of serum. A vein sample is taken where a lab or a larger panel needs more blood, as when lupus anticoagulant is tested at the same time.