Table 1 Revised classification criteria for anti-phospholipid syndrome[1]

 Vascular thrombosis

One or more episodes of arterial, venous or small vessel thrombosis in any tissue or organ (confirmed by objective validated criteria (imaging study or histopathology))

 Pregnancy complications

One or more unexplained deaths of a morphologically normal fetus ≥10th gestational week

One or more premature births (≤34th gestational week) of a morphologically normal neonate because of eclampsia, severe pre-eclampsia or placental insufficiency

Three or more unexplained consecutive spontaneous abortions ≤9th gestational week (maternal anatomic and hormonal abnormalities and chromosomal abnormalities excluded)

Laboratory criteria

 Lupus anticoagulant present in plasma

Detected according to the guidelines of the International Society of Thrombosis and Haemostasis (Scientific subcommittee on lupus anticoagulant/phospholipid-dependent antibodies)

 IgG and/or IgM anti-cardiolipin antibodies in serum of plasma

At medium/high titer (≥40 GPL or MPL or ≥99th percentile) measured by standard ELISA

 IgG and/or IgM anti-β₂ glycoprotein I antibodies in serum or plasma

Titer ≥99th percentile measured by standard ELISA, according to recommended procedures