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. Author manuscript; available in PMC: 2018 Nov 1.
Published in final edited form as: Blood Rev. 2017 Jul 30;31(6):406–417. doi: 10.1016/j.blre.2017.07.006

Table 1.

Summary of the Sydney Consensus Statement on Classification of APS.*

Antiphospholipid antibody syndrome (APS) is present if at least one of the clinical criteria and one of the laboratory criteria are met.
CLINICAL CRITERIA

  1. Vascular thrombosis

    One or more documented episodes of arterial, venous, or small vessel thrombosis in any tissue. Thrombosis must be confirmed by objective validated criteria. For histologic confirmation, thrombosis should be present without significant vessel wall inflammation.

  2. Pregnancy morbiditya
    1. 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 direct examination of the fetus, or
    2. One or more premature births of a morphologically normal neonate before the 34th week of gestation because of eclampsia or pre-eclampsia diagnosed by standard definitions, or recognized features of placental insufficiency, or
    3. Three or more unexplained consecutive spontaneous abortions before the 10th week of gestation, with maternal or hormonal abnormalities, and maternal and paternal chromosomal causes excluded.
a Investigators are strongly advised to classify subjects with obstetrical morbidity according to groups a, b, and c in populations of patients with more than one type of pregnancy morbidity.
LABORATORY CRITERIAb

  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 of Thrombosis and Hemostasis.

  2. Anticardiolipin antibody (aCL) of IgG and/or IgM isotype in serum or plasma, present in medium or high titer (>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-I antibody (anti- β2GPI) of IgG and/or IgM isotype in serum or plasma with a titer > the 99th percentile, on two or more occasions, at least 12 weeks apart, measured by a standardized ELISA.

bInvestigators are strongly urged to classify APS patients into one of the following categories:
I – more than one laboratory criteria present (any combination)
IIa – LA present alone
IIb – aCL present alone
IIc – anti- β2GPI present alone
*

Adapted from Miyakis et al. J Thromb Haemost. 2006;4:295–3061