Coagulation factors and proteinase inhibitors in the plasma of children with acute lymphoblastic leukoses. Behaviour before and during treatment according to Protocol I of the Cooperative Leukaemia Study COALL-80.

The thrombocyte count, the factor XIII (F XIII) activity, the concentration of fibrinogen (F I), prothrombin (F II), fibronectin (CIG), albumin and the proteinase inhibitors antithrombin III (AT III), alpha 2-macroglobulin (A2M), alpha 1-antitrypsin (A1A) and Cl-esterase inactivator (Cl-INA) were determined in ten children with acute lymphoblastic leukaemia (ALL). Changes due to the disease and to therapy were observed. Before the start of treatment the patients had thrombocytopenia secondary to the disease, and the proteinase inhibitors--especially Cl-INA and A1A--were raised. During the induction phase the thrombocyte count rose but there was also a marked increase in the concentration of F II and CIG. During the consolidation phase there was a general fall in protein concentration under L-asparaginase medication. The cause was attributed to a disorder of protein synthesis. The concentration of the factors studied rose again during maintenance therapy.