Clinical relevance of antiphosphatidylserine/prothrombin antibodies in antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is characterised by thrombosis and/or pregnancy morbidity associated with persistent antiphospholipid antibodies (aPL). Beyond the criteria antibodies, non-criteria aPL, particularly antiphosphatidylserine/prothrombin (aPS/PT), have emerged as clinically relevant aPL in the diagnosis of APS. aPS/PT antibodies, especially IgG, are strongly associated with thrombosis, obstetric morbidity, and LA positivity. Most importantly, aPS/PT identify high-risk aPL profiles and are detectable in seronegative APS. aPS/PT antibodies are among the most informative non-criteria aPL and add diagnostic and prognostic value in APS.