Antibody to annexin V has anti-phospholipid and lupus anticoagulant properties.

Anti-annexin V (anti-ANXV) IgG and lupus anticoagulant (LAC) were both shown to be capable of inducing apoptosis in umbilical vein endothelial cells [Nakamura et al.: Biochem Biophys Res Commun 205:1488-1493, 1994]. In the present study, we have demonstrated that anti-ANXV IgG prolongs the activated partial thromboplastin time and has an affinity for phospholipids in enzyme-linked immunosorbent assay. This indicates overlapping of anti-ANXV and LAC activities, suggesting that ANXV may be involved in the autoimmune mechanism for LAC production.