Includes any of the following:
- The presence of lupus anticoagulant as the aPL subtype most closely related to thrombosis
- The presence of double (any combination of lupus anticoagulant, anticardiolipin antibodies or antibeta2 glycoprotein I antibodies) or triple (all three subtypes) aPL positivity.
- The presence of persistently high aPL titers.

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