Collection of optimal stem cells is important for engraftment.
Collection of 2-2.5 million cells is the minimum for stem cell transplantation.
About one-third of lymphoma patients do not mobilize an adequate number of stem cells.
About 10-20% of lymphoma patients fail to collect 2 million CD34+ cells and nearly 60% do not collect four million.
Poor stem cell mobilization a function of increasing age of the patient, bone marrow disease, extensive prior chemotherapy, prior use of alkylating agents, prior radiation, especially of the pelvic areas, and use of growth factors without associated chemotherapy.
General principles include mobilizing and collecting stem cells early in the disease process, avoiding marrow toxic drugs, and irradiation prior to mobilization and use of chemotherapy plus stimulating agents.
G-CSF at higher doses leads to increased stem cell mobilization.
Stem cell collection is impaired in myeloma patients with prior lenalidomide exposure.
Mobiliation agents include G-CSF, pegfilgastrim, and plerixafor.
Perixafor binds CD34+ cells to the bone marrow stromal cell, allowing for increased mobilization of stem cells.