Antithrombin III in patients on long-term oral anticoagulants.

Bidimensional Immunoelectrophoresis Abnormal Migration of Serum Antithrombin III in Coumarin-Treated Patients

“…Antithrombin III (AT III) is the most important inhibitor of blood coagulation. In coumarin treated patients antithrombin III plasma activity was maintained to be variably increased (1,2) or unchanged (3). In agreement with the latter we have failed to show any significant change in activity during stable anticoagula tion (patient/normal ratio of about 2, using simplastin, a rabbit brain and lung thromboplastin preparation).…”

Familial venous thrombosis

“…In addition to the effects on factors II, VII, IX and X and the recently described reduction in protein C levels, there is evidence that therapy with warfarin may result in a small increase in plasma ATIII antigen (Refvem, Fagerhol and Abildgaard, 1973) and in the plasma level of ATIII measured as the ability of plasma to inhibit activated factor X (Wessler et aL., 1978). However, evidence suggesting that warfarin therapy does not influence plasma ATIII levels also exists (Bull et al, 1980;Frost and Loveday, 1980). Small increses in plasma ATIII levels have been reported in a few individuals with classical ATIII deficiency following the institution of warfarin therapy (Marciniak et al, 1974;Zucker, Gomperts and Marcus, 1976), but these increases have been small and the highest reported levels have remained without normal range; our own observations and those of other wokers suggest that warfarin therapy does not give rise to any significant increase in plasma ATIII levels in patients with classical ATIII deficiency (Leone et al, 1980;Longy et al, 1980;Laharrague et al, 1980;Tripodi et al, 1980;Winter et al, 1982e).…”