Role of antiphospholipid antibodies in kidney disease: Risk factors, immunopathogenesis, and diagnosis

Table 2 2006 Revised Sapporo criteria for antiphospholipid syndrome (also called the Sydney criteria)

Clinical criteria	Laboratory criteria
One or more of the following is present:	The presence of one or more of the following aPLs on two or more occasions at least 12 weeks apart
(1) Vascular thrombosis	IgG and/or IgM aCLs in moderate or high titer (> 40 GPL or MPL units, respectively, or a titer > 99th percentile for the testing laboratory), measured by a standardized enzyme-linked immunosorbent assay
One or more episodes of venous, arterial, or small vessel thrombosis in any tissue or organ
(2) Pregnancy morbidity	IgG and/or IgM anti-2 glycoprotein I > 40 GPL or MPL units, respectively, or a titer > 99th percentile for the testing laboratory, measured by a standardized ELISA according to recommended procedures
(a) One or more unexplained deaths of a morphologically normal fetus at ≥ 10 weeks gestation; (b) One or more premature births of a morphologically normal neonate before 34 weeks gestation because of eclampsia, preeclampsia, or placental insufficiency; and (c) Three or more consecutive spontaneous pregnancy losses at < 10 weeks gestation with maternal and paternal factors (anatomic normal and chromosomal abnormalities excluded)
	Lupus anticoagulant present in plasma, on 2 or more occasions at least 12 weeks apart

aCLs: Anticardiolipin antibodies; aPL: Antiphospholipid antibodies; ELISA: Enzyme-linked immunosorbent assay; GPL: IgG phospholipid units; IgG: Immunoglobulin G; IgM: Immunoglobulin M; MPL: IgM phospholipid units.