[Acquired deficiencies in antithrombin III and C protein during treatment with L-asparaginase].

Fourteen children treated by L-Asparaginase for acute lymphoblastic leukemia had sequential coagulation studies performed including cephalin-kaolin time, Quick time, fibrinogen, factors II, VII + X and V, as well as antithrombin III and protein C, the major coagulation inhibitors. A severe antithrombin III and protein C deficiency was observed during therapy, with a coexisting hypocoagulability. This equilibrium partially explains the lack of thrombo-embolic phenomena in these children, despite the risk factors present. Although no substitutive therapy was instituted in these cases, their use in high-risk cases is discussed.