Autologous transplantation with circulating hemopoietic stem cells

Area of Science:

• Hematology
• Stem Cell Biology
• Transplantation Medicine

Background:

• Circulating stem cells are present in sufficient quantities for collection and transplantation in mice, dogs, and humans.
• Preclinical studies in mice indicate a low concentration of circulating stem cells compared to bone marrow (1:100 ratio).
• The ratio of circulating to bone marrow stem cells is more favorable in dogs (1:10-20).

Purpose of the Study:

• To evaluate the feasibility of using circulating stem cells for transplantation in humans.
• To determine the efficacy of blood stem cell collection and transplantation for hematopoietic recovery.
• To highlight the potential advantages of using blood stem cells over bone marrow stem cells.

Main Methods:

• Pilot studies involving 10 human patients.
• Collection of mononuclear cells via leukapheresis procedures.
• Assessment of hematopoietic recovery following transplantation after ablative treatment.

Main Results:

• The approach of collecting and transplanting circulating stem cells is feasible in humans.
• Approximately 5 x 10^8 mononuclear cells/kg, collected through 7-8 leukapheresis sessions, appear sufficient for rapid hematopoietic recovery.
• Blood stem cell transplantation shows potential for faster hemopoietic recovery.

Conclusions:

• Circulating stem cells can be effectively collected and utilized for transplantation in humans.
• Blood stem cell transplantation offers potential benefits including reduced risk of malignant cell contamination, avoidance of general anesthesia, and enhanced immune recovery.
• This approach represents a viable alternative to traditional bone marrow transplantation.