Disordered hemostasis associated with severely depressed fibrinolysis demonstrated using a simultaneous thrombin and plasmin generation assay during L‐asparaginase induction therapy in pediatric acute lymphoblastic leukemia

BACKGROUND: L-asparaginase (L-Asp)-associated thromboembolisms are serious complications in pediatrics patients with acute lymphoblastic leukemia (ALL), especially at >/=10.0 years old, but the pathogenesis remains to be clarified. PROCEDURE: We conducted a multicenter, prospective study of 72 patients with ALL aged 1.0 to 15.2 years treated with either a Berlin-Frankfurt-Munster (BFM) 95-ALL oriented regimen or Japan Association of Childhood Leukemia Study ALL-02 protocol. We divided patients into each treatment protocol and investigated the dynamic changes in coagulation and fibrinolysis using simultaneous thrombin and plasmin generation assay. Patients' plasma samples were collected at the prephase (T0), intermittent phase (T1), and postphase of L-Asp therapy (T2), and postinduction phase (T3). Measurements of endogenous thrombin potential (T-EP) and plasmin peak height (P-Peak) were compared to normal plasma. RESULTS: None of the cases developed thromboembolisms. Median ratios of T-EP and P-Peak for the controls in the JACLS group were 1.06 and 0.87 (T0), 1.04 and 0.71 (T1), 1.02 and 0.69 (T2), and 1.20 and 0.92 (T3), respectively, while those in the BFM group were 1.06 and 1.00 (T0), 1.04 and 0.64 (T1), 1.16 and 0.58 (T2), and 1.16 and 0.85 (T3), respectively. In particular, P-Peak ratios were depressed at T1 and T2 compared to T0 in the BFM group (P /=10.0 years old were lower at T1 in the BFM group (P = .02). CONCLUSIONS: The results demonstrated that hemostatic dynamics appeared to shift to a hypercoagulable state with marked hypofibrinolysis associated with L-Asp therapy, especially in patients >/=10.0 years old following the BFM regimen.