Antiphospholipid syndrome (APS) is a clinical and laboratory entity consisting of persistent antibodies directed against antiphospholipid (aPL) in conjunction with recurrent venous or arterial thrombosis and obstetric signs.
Clinical criteria | Laboratory criteria |
---|---|
Thrombosis: | Circulating lupus anticoagulant, measured by International Society on Thrombosis and Hemostasis (ISTH) criteria |
Obstetric signs:
| Anticardiolipin antibodies (IgG or IgM), in moderate or high titre (> 40 GPL or MPL, or > 99th percentile), measured by a standardized ELISA |
Anti-ß2-glycoprotein-1 antibodies (IgG or IgM), present in titre > 99th percentile, measured by a standardized ELISA |
APS can occur even in the absence of any autoimmune disease, in which
case it is referred to as primary APS.
Where it arises in a patient presenting an autoimmune disease, the term
"secondary APS" is used.
If an autoimmune disease is diagnosed in a patient with primary APS, the
latter is subsequently referred to as secondary APS.