Screening for coagulopathy and identification of children with acute lymphoblastic leukemia at a higher risk of symptomatic venous thrombosis: an AIEOP experience.

Introduction: Venous thromboembolic events (VTEs) are frequent complications of childhood acute lymphoblastic leukemia (ALL) treatment. The aim of the study was to evaluate the rate of symptomatic VTEs in children with ALL and the predictive value of clinical and biological factors and routine monitoring of coagulation parameters in identifying children at a higher risk of this complication. Materials and Methods: Between September 2000 and July 2006, 2042 children (≥1 and younger than 18 y) with newly diagnosed ALL were enrolled in Italy in the AIEOP (Italian Association of Pediatric Hematology and Oncology)-BFM (Berlin-Frankfurt-Muenster) ALL 2000 trial. Patients with symptomatic VTEs (deep venous thromboses or cerebral venous thromboses) were identified after a careful review of clinical records. The impact of coagulation derangement at the onset of VTEs was evaluated by a nested case-control study. Results: Forty-eight (2.4%) children presented with a VTE. The rate of VTEs was higher in male patients (P=0.001); patients randomized to receive dexamethasone tended to have a higher rate of VTE compared with those who received prednisone (P=0.10). The coagulation derangement at the onset of VTE was not associated with VTE occurrence. The prevalence of a factor V Leiden G1691A mutation and the prothrombin G20210A variant was higher in children with VTE than that expected in the general population.