There is controversy surrounding the relationship between iron overload and outcomes with red blood cell (RBC) transplantation in patients with myelodysplastic syndrome (MDS). Initial data have demonstrated a correlation between iron overload and serum ferritin with non-relapse mortality in the transplant setting. However, a recent meta-analyses did not demonstrate a correlation, says Thomas Prebet, MD.

Methods used to evaluate iron overload may be inconsistent across these studies, cautions Prebet, as some investigators use serum ferritin, while others use magnetic resonance imaging. Moreover, some of these analyses do not focus on the acute myeloid leukemia (AML) or MDS populations. This is important, since iron overload may impact leukemic stem cells, leukemic progenitors, and normal progenitors, Prebet believes. Randomized studies exploring iron overload in AML and MDS are needed.

Iron overload is associated with a high RBC transfusion burden, which is usually a surrogate marker for aggressive disease, notes Prebet. Iron overload has also had some correlation with a small increase in infection after transplantation and the occurrence of veno-occlusive disease. Although there is no clear explanation for this correlation, intervention before and after transplantation may have some impact on these complications and overall outcome, suggests Prebet.