Haematological Recovery After High-dose Consolidation Chemotherapy with Peripheral Blood Progenitor Cell Rescue: the Effects of the Mobilization Regimen and Post-transplant Growth Factors

Purpose: Peripheral blood progenitor cells (PBPC), mobilized by chemotherapy, growth factors (GF) or the combination of these modalities are currently used in most autologous transplants settings. Patient selection factors and infused cell numbers have been related to the rate of haematological recovery after transplant (p-Tx). The effect of the mobilization regimen on haematological recovery has rarely been reported and is addressed herein. The value of p-Tx GF use is also evaluated.

Methods: A literature review identified studies reporting both mobilization results and haematological recovery (time to ANC > 0.5 or 1.0 x 10(9)/1 and PLT > 20 or 50 x 10(9)/1). The studies are listed in tables showing the mobilization regimen, disease, infused CD34+ cell and CFU-GM dose, p-TX GF use and haematological recovery. The ranges of recovery times for each transplant setting are summarized in a figure in addition to the ranges of recovery times using GF after autologous bone marrow transplants in controlled studies.

Results: Transplantation of cells mobilized by G-CSF results in faster haematological recovery than transplantation of cells mobilized by GM-CSF. This difference disappears when chemotherapy is included in the mobilization regimen. GF have minimal effect on haematological recovery after transplantation of PBPC mobilized by chemotherapy plus GF and some effect on neutrophil recovery after transplants of PBPC mobilized by GF only.

Conclusions: Recovery after PBPC transplantation depends on the mobilization method and is best predictable when mobilization occurs with chemotherapy plus GF. In this situation, the value of post-transplant growth factors is questionable. Careful choice of the mobilization method, including optimal timing of leucapheresis and patient selection factors, determine the leucapheresis yield and thus the rate of haematological recovery.