Mobilization, collection, and immunomagnetic selection of peripheral blood CD34 cells in recovered aplastic anemia patients.

Background: Most patients with severe aplastic anemia (sAA) respond to immunosuppression, but a significant number relapse or develop clonal abnormalities such as paroxysmal nocturnal hemoglobinuria, myelodysplasia, or leukemia. In principle, patients without matched sibling donors and older patients might benefit from transplantation of autologous hematopoietic peripheral blood progenitor cells (PBPCs) obtained during remission. Even patients who have clinically recovered from aplastic anemia have diminished hematopoietic progenitor cells, so the practicability of PBPC mobilization in these individuals is unknown.

Study Design And Methods: The feasibility of PBPC mobilization in nine patients with a history of sAA was evaluated. Granulocyte-colony-stimulating factor (10 microg/kg) was administered subcutaneously for 5 days and followed by a 12-L leukapheresis procedure.

Results: Only two of the nine patients had sufficient mobilization of CD34 cells to merit collection; in these cases sufficient CD34 cells were obtained for autologous transplantation should the need arise.

Conclusion: PBPC collection is feasible only in a fraction of recovered AA patients.