The role of iron in patients after bone marrow transplantation

Haemopoietic stem cell transplantation (HSCT) is an important intervention for malignant and non-malignant blood diseases. However, HSCT is also associated with considerable morbidity and mortality, some of which may be related to iron overload. Levels of serum iron are elevated in patients undergoing HSCT as a result of disturbed iron metabolism, pre-transplantation blood transfusions, or cytotoxic therapy for conditioning before HSCT. The complications of iron overload in HSCT patients include infections, mucositis, chronic liver disease (fibrosis progression), sinusoidal obstruction syndrome, and idiopathic pneumonia syndrome. Iron overload has an adverse impact on survival in patients undergoing HSCT for beta-thalassaemia major or haematological malignancies including myelodysplastic syndromes. It has been suggested that all candidates for and all survivors of HSCT should be screened for iron overload at various time points before and after transplantation. Few studies of iron chelation therapy after HSCT have been reported, but one small study has indicated that deferoxamine is at least as effective as phlebotomy in reducing post-transplantation iron overload in patients with beta-thalassaemia major. The new oral chelator deferasirox may be better tolerated than phlebotomy or deferoxamine infusion, and two prospective phase II studies in patients with iron overload after HSCT are now recruiting candidates.