Cryopreserving human peripheral blood progenitor cells

Area of Science:

• Hematology
• Oncology
• Cell Biology

Background:

• High-dose chemotherapy with autologous peripheral blood progenitor cell (PBPC) transplantation treats chemosensitive malignancies.
• Standard cryopreservation uses 10% dimethyl sulfoxide (DMSO), which can cause toxic reactions upon infusion.
• Toxicity is dose-dependent, prompting investigation into lower DMSO concentrations.

Purpose of the Study:

• To evaluate the efficacy of cryopreserving human PBPC using reduced concentrations of DMSO (5%, 4%, and 2%) compared to the standard 10%.
• To assess the impact of varying DMSO concentrations on the viability, apoptosis, and necrosis of CD34+ cells.
• To determine the preservation of mature colony-forming (CFU) cells, including myeloid, erythroid progenitors, CFU-megakaryocytes, and long-term culture-initiating cells (LTC-ICs).

Main Methods:

• PBPC were cryopreserved with DMSO concentrations of 10% (control), 5%, 4%, and 2%.
• Viability, apoptosis, and necrosis of CD34+ cells were analyzed.
• Preservation of CFU-myeloid, CFU-erythroid, CFU-megakaryocytes, and LTC-ICs was assessed using 5% and 10% DMSO.
• All samples were frozen using a rate-controlled programmed freezer and stored in liquid nitrogen vapor phase.

Main Results:

• Cryopreservation with 5% DMSO demonstrated optimal preservation of CD34+ cell viability and function.
• Reduced DMSO concentrations showed a trend towards decreased apoptosis and necrosis compared to 10% DMSO.
• Key progenitor cell populations, including LTC-ICs, were well-preserved with 5% DMSO.

Conclusions:

• 5% DMSO is the optimal concentration for cryopreserving human PBPC in vitro.
• This concentration effectively balances cell preservation with reduced toxicity.
• Several hospitals have adopted 5% DMSO as the standard cryoprotectant for autologous PBPC transplantation.