Role of fibrinolytic and clotting parameters in the diagnosis of liver veno-occlusive disease after hematopoietic stem cell transplantation in a pediatric population.

Hepatic veno-occlusive disease (VOD) is a severe complication after hematopoietic stem cell transplantation (HSCT). Recent studies, mainly in adults receiving HSCT, have identified an increase in the plasminogen activator inhibitor-1 (PAI-1) as a possible marker of VOD. To confirm this finding, the fibrinolytic, coagulation and liver function parameters were assayed before and weekly for 1 month after 61 HSCT performed in 53 consecutive children. Non-VOD patients had a slight increase in t-PA antigen, fibrinogen and P-selectin levels, as well as a mildly longer aPTT and a drop in antithrombin after HSCT. The 6 children with VOD (9.84%) had an early and significant increase in PAI-1 antigen and activity (p<0.0001), t-PA antigen (p<0.0001) and D-dimer (p<0.01) levels, and a decrease in plasminogen, alpha 2-antiplasmin and PT emerged 2(+/-1) days before the clinical diagnosis of VOD by comparison with mean post-HSCT values in the non-VOD patients. Significant differences were also detected for these parameters and antithrombin levels between non-VOD and VOD patients soon after the clinical onset of VOD, whereas the rise in bilirubin levels became significant only later on. In conclusion, variations in fibrinolytic test findings after HSCT, and PAI-1 in particular, may facilitate the early diagnosis of VOD in pediatric patients after HSCT.