PLASMA-ACTIVATED FACTOR-VII LEVEL IN PATIENTS POSITIVE FOR LUPUS ANTICOAGULANT

We examined plasma levels of activated factor VII (F VIIa) in 50 patie nts positive for lupus anticoagulant (LA), in 83 patients negative far LA, and in 10 healthy volunteers as controls, Plasma F VIIa was prese nt in healthy volunteers; its level was significantly increased, compa red to the level in the controls, in patients with thrombosis, collage n diseases, and disseminated intravascular coagulation (DIG), suggesti ng that it reflected a thrombotic state. Plasma F VIIa was correlated with thrombin-antithrombin complex (TAT) in patients negative far LA b ut showed no such correlation in those positive for LA. Plasma F VIIa was negatively correlated with activated partial thromboplastin time ( APTT) in patients positive for LA, but not in those negative for LA, s uggesting that LA could inhibit the F VIIa assay system. Plasma F VIIa level was significantly increased in patients with thrombotic disease s; however, in patients positive for LA, it is possible that increased plasma F VIIa level may not be correlated with thrombogenicity. (C) 1 997 Wiley-Liss, Inc.