The donor's dilemma

In this issue of Blood, Pulsipher et al identify key differences in adverse events related to donation for hematopoietic cell transplantation (HCT) from a prospective cohort of nearly 9500 unrelated allogeneic donors recruited through the National Marrow Donor Program.1 Although the rates of life-threatening complications were very low overall (<0.3%) for donors of both peripheral blood and bone marrow, those donating bone marrow had a 4-fold increased risk of experiencing a serious adverse event. Most adverse events were acute in nature, resolving within a matter of days to weeks, and importantly, no deaths as a result of donation procedures occurred. This prospective study, with more than 20 000 donor-years of follow-up after granulocyte colony-stimulating factor administration, also showed no increased risk for hematologic or other cancers, autoimmune diseases, or thrombosis associated with growth factor mobilization. In fact, donors in this cohort had a significantly lower incidence of cancer compared with the general population, regardless of granulocyte colonystimulating factor exposure.