Pregnancy Loss in the Antiphospholipid-Antibody Syndrome — A Possible Thrombogenic Mechanism

The presence of antiphospholipid antibodies in serum has been associated with the antiphospholipid-antibody syndrome, which is characterized by arterial and venous thrombosis or recurrent pregnancy loss attributed to placental thrombosis. 1 – 6 The pathogenic mechanisms of this disorder are unknown. Remarkably, “lupus anticoagulants” — antibodies against anionic phospholipids or associated proteins, which inhibit phospholipid-dependent blood coagulation — are frequently found in patients with this disorder. Yet, paradoxically, these anticoagulants are associated with thrombotic manifestations and not with bleeding disorders. Annexin V (previously known as placental anticoagulant protein I and vascular anticoagulant α) is found in placenta and vascular endothelium, among other . . .