Antiphospholipid Syndrome: definition Posted by: Cleo Libonati, RN, BSN in DICTIONARY 0 2,082 Views An autoimmune disease characterized by defined clinical features (vascular thrombosis and/or complications of pregnancy) and laboratory criteria (anticardiolipin and/or lupus anti-coagulant antibodies). Glossary. 2013-04-08 Cleo Libonati, RN, BSN