LUPUS ANTICOAGULANT ANTIBODIES - RECOGNITION OF PHOSPHOLIPID-BINDING PROTEIN COMPLEXES

Lupus anticoagulant antibodies form a heterogeneous group of antiphosp holipid antibodies with rather poorly defined antigens. The role that phospholipid-binding proteins play in lupus anticoagulant antibody act ivity is a subject of current investigation. Several candidate protein s have been proposed, including beta(2)-glyooprotein I (beta(2)GPI), p rothrombin, and annexin V. As beta(2)GPI-dependent lupus anticoagulant s will be reviewed elsewhere in this issue, this paper will focus on t he involvement of prothrombin and annexin V in lupus anticoagulant act ivity. Evidence for a role for these proteins in the reactivity and in duction of lupus anticoagulant antibodies will be discussed, as well a s an apparent requirement for both phospholipid and phospholipid-bindi ng protein. The data presented here suggest that some lupus anticoagul ant antibodies recognize and may be induced by complexes of phospholip id and phospholipid-binding proteins, in particular, phospholipid and prothrombin or annexin V.