Snapshot A 40-year-old woman with systemic lupus erythematosus presents for evaluation of recurrent deep venous thromboses. In the past year, she has had 5 events. On further questioning, she also reveals a history of having 2 spontaneous abortions at > 10 weeks gestation. Today, her physical exam is unremarkable. Blood testing reveals a positive antinuclear antibody and lupus anticoagulant. She is started on anticoagulation. Introduction Clinical definition an autoimmune disorder, often associated with systemic lupus erythematosus (SLE), characterized by thromboses and recurrent spontaneous abortions Epidemiology Incidence increases with age Demographics female > male affects adults Risk factors SLE drugs procainamide isoniazid hydralazine oral contraceptives malignancy ETIOLOGY Pathogenesis autoantibodies (lupus anticoagulant, anticardiolipin, and anti-β2 glycoprotein antibodies) react against platelet membranes or prothrombin-platelet membrane complex, activating endothelial cells and platelets this activates complement-mediated thrombosis Associated conditions SLE other autoimmune diseases preeclampsia or eclampsia Presentation Symptoms recurrent fetal loss symptoms related to thrombosis site dyspnea abdominal discomfort neurologic symptoms chest pain skin rash Physical exam cutaneous findings include livedo reticularis reticular (lacy) or mottled violaceous rash Studies Labs lupus anticoagulant prolonged dilute Russell viper venom time (DRVVT) test prolonged partial thromboplastin time (PTT) anti-β2 glycoprotein (IgG and IgM) anticardiolipin (IgG and IgM) coagulation studies normal or slightly prolonged prothrombin time normal bleeding time normal platelet count false positives due to antibodies + VDRL/RPR due to anticardiolipin antibodies prolonged PTT due to lupus anticoagulant not corrected by adding normal platelet-free plasma Differential Factor V Leiden mutation distinguishing factor absence of antibodies Antithrombin deficiency distinguishing factor normal PTT DIAGNOSIS Based on clinical presentation and laboratory studies Diagnostic criteria includes ≥1 clinical and ≥1 laboratory criteria clinical thrombosis spontaneous abortion at ≥ 10 weeks gestational age premature birth at < 35 weeks gestational age due to eclampsia, pre-eclampsia, or placental insufficiency ≥ 3 spontaneous abortions before < 10 weeks gestational age laboratory lupus anticoagulant anticardiolipin antibody anti-β2 glycoprotein Treatment Medical warfarin indications for non-pregnant patients prevention of thrombosis target INR 2-3 aspirin plus unfractionated heparin indications for pregnant patients prevention of pregnancy loss Complications Fetal loss Stroke Prognosis Risk of recurrence is high