Mobilization of circulating haemopoietic cells (blood stem cells) by GM-CSF in patients with malignancies.

Autologous reinfusion of circulating haemopoietic progenitor and stem cells (blood stem cell transplantation) has emerged as an alternative to autologous bone marrow transplantation in a variety of malignant diseases. Major obstacles associated with harvest of blood stem cells by leukapheresis are: 1. relatively high costs, and 2. discomfort caused to the patient, as generally five to ten settings of leukapheresis are necessary to harvest a number of blood stem cells sufficient for haemopoietic restitution following myeloablative therapy. GM-CSF recently has been shown to effectively increase circulating haemopoietic cells, when given subsequent to even highly-toxic therapy. This report summarizes our data on mobilization of blood stem cells by GM-CSF cells in multiple myeloma patients.