Granulocyte-colony stimulating factor (filgrastim, G-CSF) represents a standard mobilizing cytokine, which is being used to prepare allogeneic donors before hematopoietic progenitor cells collection with apheresis for more than a decade. While its short-term effects are sufficiently known, long-term influence on donor’s health is less discovered as well as whole mechanism of mobilization. Although any negative impact of short-term filgrastim application has not been displayed in healthy individual yet, the discussion about possible association with increased risk of malignant disease, especially leukemia, is still in progress. Maximal donors’ health protection is a main rule in allogeneic hematopoietic progenitor cells collections. Both medical and ethical questions of donation require to keep the issue of the long-term effects of G-CSF application in mind during the daily work with allogeneic donors. It is appropriate to reduce filgrastim dosage to necessary minimum, to provide donor with information about up to date knowledge regarding filgrastim long-term effects and extend the follow-up period after the donation too.

        Key words: filgrastim, healthy donors, peripheral blood stem cells, leukemogenesis