Storage of hemopoietic stem cells

Area of Science:

• Hematology
• Cell Biology
• Transplantation Medicine

Background:

• Hemopoietic stem cells (HSC) and therapeutic cells (TC) require cryopreservation for storage exceeding 48 hours.
• Ensuring the quality of stored cells is critical for successful reinfusion and transplantation outcomes.

Purpose of the Study:

• To review critical variables affecting the quality of stored HSC and TC.
• To discuss the regulatory framework for ensuring stem cell and TC quality in transplantation.

Main Methods:

• Review of factors influencing stem cell quality during storage.
• Examination of cryopreservation parameters: cell concentration, temperature, freezing rates, and cryoprotectants (DMSO, HES).
• Assessment of quality control metrics: total nucleated cell count (TNC), CD34+ cell count, and colony-forming units - granulocyte macrophage (CFU-GM).

Main Results:

• Key variables impacting HSC and TC quality include cell concentration, temperature, collection-to-cryopreservation interval, and freezing methods.
• Dimethyl sulfoxide (DMSO) is the primary cryoprotectant, often combined with hydroxyethyl starch (HES).
• Total nucleated cell count (TNC) and CD34+ cell counts are useful quality indicators, with engraftment potential being the ultimate measure.

Conclusions:

• Validated procedures addressing critical variables are essential for high-quality HSC and TC storage.
• Comprehensive quality assessment of stem cell products before and after storage is mandatory.
• Adherence to regulatory guidelines (JACIE, EU Directive) ensures quality systems in stem cell laboratories.