Revised classification criteria for the antiphospholipid antibody syndrome8
| Clinical criteria (one or more must be present) . |
|---|
| Vascular thrombosis: One or more episodes of arterial, venous, or small-vessel thrombosis affecting any tissue or organ |
| Pregnancy morbidity |
| One or more unexplained deaths of a morphologically normal fetus at or after the 10th week of gestation |
| One or more premature births of a morphologically normal neonate at or before the 34th week of gestation because of severe preeclampsia or eclampsia, or severe placental insufficiency |
| Three or more unexplained, consecutive spontaneous abortions before the 10th week of gestation |
| Laboratory criteria (one or more must be present) |
| LAC present in plasma, on 2 or more occasions at least 12 weeks apart, detected according to the guidelines of the International Society on Thrombosis and Hemostasis* |
| aCL (IgG or IgM) present in medium or high level (ie, > 40 GPL or MPL, or > 99th percentile) on 2 or more occasions at least 12 weeks apart, measured by a standardized ELISA |
| Anti-β2 glycoprotein-I antibody of IgG and/or IgM antibodies in serum or plasma (in level > the 99th percentile), present on 2 or more occasions, at least 12 weeks apart, measured by a standardized ELISA. |
| Clinical criteria (one or more must be present) . |
|---|
| Vascular thrombosis: One or more episodes of arterial, venous, or small-vessel thrombosis affecting any tissue or organ |
| Pregnancy morbidity |
| One or more unexplained deaths of a morphologically normal fetus at or after the 10th week of gestation |
| One or more premature births of a morphologically normal neonate at or before the 34th week of gestation because of severe preeclampsia or eclampsia, or severe placental insufficiency |
| Three or more unexplained, consecutive spontaneous abortions before the 10th week of gestation |
| Laboratory criteria (one or more must be present) |
| LAC present in plasma, on 2 or more occasions at least 12 weeks apart, detected according to the guidelines of the International Society on Thrombosis and Hemostasis* |
| aCL (IgG or IgM) present in medium or high level (ie, > 40 GPL or MPL, or > 99th percentile) on 2 or more occasions at least 12 weeks apart, measured by a standardized ELISA |
| Anti-β2 glycoprotein-I antibody of IgG and/or IgM antibodies in serum or plasma (in level > the 99th percentile), present on 2 or more occasions, at least 12 weeks apart, measured by a standardized ELISA. |
The diagnosis can be made only if BOTH one clinical criterion AND one laboratory criterion are present. ISTH criteria for LAC include (1) prolongation of a phospholipid-dependent screening assay; (2) evidence of the inhibitory activity with mixing studies; (3) evidence that the inhibitory activity is phospholipid dependent; and (4) distinction from other coagulopathies.9