Leukapheresis components may be cryopreserved at high cell concentrations without additional loss of HPC function

Area of Science:

• Hematology
• Cellular Biology
• Cryopreservation Science

Background:

• Mobilized peripheral blood progenitor cell (PBPC) cryopreservation traditionally uses lower cell concentrations.
• Higher concentrations may reduce processing costs and transfusion-related complications.
• Assessing feasibility of higher concentration cryopreservation is crucial for optimizing stem cell therapies.

Purpose of the Study:

• To evaluate the feasibility of cryopreserving PBPC components at concentrations exceeding standard recommendations.
• To determine the impact of higher cell concentrations on PBPC viability, recovery, and function post-thaw.
• To analyze hematologic recovery in patients receiving PBPCs cryopreserved at elevated concentrations.

Main Methods:

• Cryopreservation of apheresis components at standard and higher cell concentrations (aliquots and split bags).
• Assessment of cell viability, nucleated cell recovery, and cloning efficiency post-thaw.
• Analysis of hematologic engraftment in patients undergoing autologous transplantation with high-concentration PBPCs.

Main Results:

• Median cell concentrations at freezing reached up to 332 x 10^6/mL in high-concentration samples.
• Significantly lower viability was observed in samples frozen at higher concentrations (83% vs. 92% and 77% vs. 87%).
• No significant differences in nucleated cell recovery or post-thaw cloning efficiency were found; engraftment times were comparable.

Conclusions:

• Cryopreservation of PBPC components at 3.3-fold higher cell concentrations is feasible.
• Elevated cryopreservation concentrations do not adversely affect hematopoietic progenitor cell (HPC) function post-thaw.
• This approach holds promise for more efficient and cost-effective stem cell banking and transplantation.