Table 1 Revised Sapporo criteria for the antiphospholipid syndrome (APS) [8]

Clinical Criteria

 1. Vascular thrombosis: One or more presence of arterial, venous, or small vessel thrombosis in any tissue or organ. Thrombosis must be verified by objective validated criteria, i.e., unequivocal findings of appropriate imaging studies or histopathology. For histologic confirmation, thrombosis should be present without remarkable inflammation in the vessel wall.

 2. Pregnancy morbidity:

  • One or more unexplained deaths of a morphologically normal fetus at or beyond the 10th week of gestation, with normal fetal morphology documented by ultrasound or by direct examination of the fetus.

  • One or more premature births of a morphologically normal neonate before the 34th week of gestation because of: eclampsia or severe preeclampsia defined according to standard definitions or recognized features of placental insufficiency.

  • Three or more unexplained consecutive spontaneous abortions before the 10th week of gestation, with maternal anatomic or hormonal abnormalities and paternal and maternal chromosomal causes excluded.

In studies of populations of patients who have more than one type of pregnancy morbidity, investigators are strongly encouraged to stratify groups of subjects according to one of the three criteria above.

Laboratory Criteria:

 1. Lupus anticoagulant (LA) present in plasma, on two or more occasions at least 12 weeks apart, detected according to the guidelines of the International Society on Thrombosis and Haemostasis (Scientific Subcommittee on LAs/phospholipid-dependent antibodies).

 2. Anticardiolipin (aCL) antibody of IgG and/or IgM isotype in serum or plasma, present in medium or high titer (i.e., > 40 GPL or MPL, or > the 99th percentile) on two or more occasions, at least 12 weeks apart, measured by a standardized ELISA.

 3. Anti-β2-glycoprotein 1 antibody of IgG or IgM isotype, or both, in serum or plasma (in titers greater than the 99th percentile) present on two or more occasions, at least 12 weeks apart, measured by a standardized ELISA, according to recommended procedures.