RESUMO
BACKGROUND: Endothelial dysfunction has been reported in children with acute lymphoblastic leukemia (ALL). The aim of this study is to assess Von Willebrand Factor antigen (VWF antigen) and Factor VIII (FVIII) in newly diagnosed ALL patients, in relation to peripheral blast (PB) cells, steroid therapy, and any prognostic potential. PROCEDURE: VWF antigen and FVIII were assessed initially (D0) and at day 8 (D8) steroid therapy for 32 newly diagnosed ALL patients with and without peripheral blood blast cells. RESULTS: At diagnosis, patients with PBs had a significantly higher levels of VWF antigen (102.7 ± 22.9% vs. 56.9 ± 8%, P<0.001) and FVIII (93.4 ± 15.9% vs. 6 62.6 ± 18.1%, P<0.001) than those without. Following steroid therapy, both factors decreased in those with PBs, whereas an increase above baseline was observed in those without PBs. Furthermore, there was a significant positive correlation between PBs and both VWF antigen (P<0.001) and FVIII levels (P=0.002). High-risk patients were comparable with standard-risk group in mean values of VWF antigen (P=0.234) and FVIII (P=0.891) at diagnosis. After 12 months from diagnosis, all patients without PB achieved and maintained complete remission. Those with initial PB reported relapse (12.5%) or death (4.2%) during follow-up. CONCLUSIONS: Markers of endothelial dysfunction namely VWF and FVIII were related to circulating blast cells and steroids therapy through lysis of lymphoblasts results in reduction of both factors, with risk of thrombosis during induction with marked disintegration of malignant cells.