The relevance of plasminogen activator inhibitor 1 (PAI-1) as a marker for the diagnosis of hepatic veno-occlusive disease in patients after bone marrow transplantation

Hepatic veno-occlusive disease (VOD) is the third most important fatal complication in allogeneic bone marrow transplantation (BMT), the second most significant one in the autologous setting and the most severe of all the regimen related toxicities. A growing number of VOD cases has to be expected due to the increasing number of high dose chemotherapies given with consecutive stem cell transplantation in patients with solid tumors. Confirmation of the diagnosis of VOD by biopsy is associated with a high risk of severe bleeding complications and, unfortunately, until now reliable laboratory markers have not as yet been established. Recently, plasminogen activator inhibitor 1 (PAI-1), the main inhibitor of the fibrinolytic system, has been found to be significantly elevated in VOD patients probably reflecting hypofibrinolysis in these patients. Furthermore, PAI-1 was able to distinguish between patients with VOD and those with hyperbilirubinemia after BMT caused by graft-versus-host-disease (GVHD) or toxic effects, in which cases the PAI-1 levels were mostly within the normal range. In this overview we summarize the data strongly indicating that PAI-1 is a useful marker for the diagnosis of VOD and helps in the differential diagnosis of hyperbilirubinemia after BMT.