Presence of anti-PS/PT IgG or IgM antibodies indicates a high risk category of patients
Antiphospholipid antibodies are not directed against phospholipids, but rather to phospholipid-protein complexes. Recent evidence suggests that antibodies to the complex of PS and PT (PS/PT) identifies a distinct subset of patients with very high likelihood of adverse events. Antibodies targeted to either PS or PT yield less clinically relevant information as antibodies towards the PS/PT complex.
Recent studies have shown that the risk of thrombotic events increases with the number of positive test results in APS patients and aPL carriers. Triple positivity for LAC, anti-β2GP1, and PS/PT demonstrated the highest diagnostic accuracy out of 23 possible combinations of aPL tests.
Inclusion of PS/PT testing into routine testing can improve patient outcome.
Anti-β2GP1 domain 1 antibodies are highly specific for the diagnosis of APS and may help support therapeutic decision making
Anti-β2GP1 antibodies target multiple epitopes in the same molecule. A growing body of evidence indicates that domain 1 is the most relevant epitope targeted by anti-β2GP1 antibodies in patients with APS. Many studies have shown that anti-domain 1 antibodies identify a distinct population of patients with a high risk of thromboembolic events, despite therapy. In addition, carriers are high risk to develop a first thromboembolic event.