Complications of allogeneic bone marrow transplantation.

Recent research has increased our understanding of the pathogenesis and prevention of the immediate and delayed complications of allogeneic bone marrow transplantation. Cytokines appear to play a major role in the pathogenesis of acute graft-versus-host disease and new therapies are being developed to modulate these effects. Risk factors for fatal venoocclusive disease of the liver such as elevated serum transaminase levels and fever prior to transplantation can be used in mathematical models to predict the outcome of venoocclusive disease. Use of total-body irradiation in pretransplantation conditioning regimens increases the risk of secondary cancers and is being used less commonly in patients with nonmalignant hematologic conditions. For patients with malignant diseases, fractionation of total-body irradiation have been shown to delay the onset and reduce the severity of radiation-induced cataracts. These and other late effects such as the development of chronic graft-versus-host disease and associated infections are major determinants of the quality of life following allogeneic marrow transplantation. Increased understanding of these complications assists the hematologist in long-term follow-up care of the marrow graft recipient.