Hepatic veno-occlusive disease (VOD), a common complication of
bone marrow transplantation (BMT), is a result of intensive conditioning by chemo-
radiotherapy. Endometrial injury causes
fibrin deposition in the affected hepatic venules, leading to abnormal laboratory parameters followed by lethal full-blown disease. Previous studies have shown that
unfractionated heparin can prevent VOD in BMT patients. Since
low molecular weight heparin (
LMWH) preserves the antithrombotic, but not the
anticoagulant, activity of
unfractionated heparin, we initiated a pilot study to determine the safety of
LMWH for the prevention of VOD. Sixty-one patients undergoing BMT (allogeneic, n=24; autologous, n=37) were randomized to receive
subcutaneous injection of
enoxaparin (40 mg/day x 1) or a placebo prior to BMT conditioning and until day 40 after
transplantation or discharge from the hospital.
LMWH administration did not influence marrow engraftment, nor was it associated with
bleeding tendency. Hemorrhagic events occurred significantly less frequently (P=0.025) were shorter duration (P=0.006) in the
LMWH group than in the placebo group. Time to platelet recovery was significantly shorter (16.5 vs 29.6 days, (P=0.0075), and
platelet transfusion requirements were lower (p=0.05) in the
LMWH patients. VOD parameters occurred less frequently in the experimental group, including duration of elevated
bilirubin levels (P=0.01) and incidence of
hepatomegaly (P=0.04).
LMWH, which seems to enhance platelet recovery, may be safely administrated to BMT patients in an attempt to prevent VOD of the liver.