Objective: To explore the safety and efficacy of low dose heparin for the prevention of hepatic veno-occlusive disease (VOD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) conditioned with busulfan and cyclophosphamide (BU-CY2) and the ideal time frame of the heparin administration.
Methods: From April 1997 to December 2005, 134 patients (75 male, 59 female; median age 25 years old) were transplanted in our bone marrow transplantation unit. All patients were conditioned with BU-CY2 or busulfan-based regimen and scheduled to receive a continuous injection of heparin at a dose of 100 IUxkg-1xd-1. The patients were divided into different groups: 87 patients received related donor transplantation and 47 patients unrelated donor transplantation; 40 patients had abnormal liver function prior to transplantation and the remaining 94 patients normal liver function; 68 patients received heparin from day -7 to day +21 post HSCT and the other 66 patients from day -7 to day +14.
Results: All 134 patients had sustained engraftment. The median time for neutrophils to reach 0.5 x 10(9)/L and for platelets to reach 20x10(9)/L were 12 days (range 9-28) and 20 days (range 6-65), respectively. The disease-free survival at day +100 for leukemia patients was 82.2% (97/118). None of 134 patients developed VOD (0%), including 10 patients with class 3 thalassemia major. The incidence and severity of clinical bleeding events in 15 patients monitored with prothrombin time and activated partial thromboplastin time is comparable with those not monitored.
Conclusions: It is suggested that low dose heparin alone is effective and safe for the prophylaxis of VOD following allo-HSCT conditioned with BU-CY regimen. Shortening the duration of administering heparin from -7 d to +21 d to -7 d to +14 d does not affect the effectiveness of low dose heparin to prevent VOD.