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Long-Term Quality Control Program Plan for Cord Blood Banks in Korea: A Pilot Study for Cryopreservation Stability
Soo Hyun Seo1,2,3, Sue Shin1,2,3, Eun Youn Roh1,2,3
1Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea.
Insights
Cryopreserved cord blood quality remains stable for up to two years. However, cell viability and CD34⁺ cell counts significantly decrease after thawing, impacting transplantation suitability.
Area of Science:
- Hematology
- Cell Biology
- Cryobiology
Background:
- Maintaining the quality of cryopreserved cord blood is critical for transplantation.
- This study presents findings from an internal quality control program for a cord blood bank.
Purpose of the Study:
- To evaluate the quality of cryopreserved cord blood units over time.
- To assess the impact of cryopreservation and thawing on key cell parameters.
Main Methods:
- Cord blood units unsuitable for transplantation were used for monthly quality control.
- Units were cryopreserved and thawed annually, with analysis of total nucleated cell count, CD34⁺ cell count, viability, and colony-forming units.
Main Results:
- No significant differences were found in cell counts or viability between samples cryopreserved for one and two years.
- Significant decreases in cell viability and CD34⁺ cell counts were observed post-thawing compared to pre-cryopreservation.
- Capillary storage methods for quality control showed consistency with standard unit testing.
Conclusions:
- Findings suggest cryopreserved cord blood quality is maintained for up to two years.
- The study provides data to inform the optimal storage duration for cord blood units intended for transplantation.
Background:
Maintaining the quality of cryopreserved cord blood is crucial. In this pilot study, we describe the results of the internal quality control program for a cord blood bank thus far.
Methods:
Donated cord blood units unsuitable for transplantation were selected for internal quality control once a month. One unit of cord blood, aliquoted into 21 capillaries, was cryopreserved and thawed annually to analyze the total nucleated cell count, CD34⁺ cell count, cell viability test, and colony-forming units assay.
Results:
No significant differences in the variables (total nucleated cell count, cell viability, CD34⁺ cell count) were observed between samples cryopreserved for one and two years. Upon comparing the variables before cryopreservation and post thawing with the capillaries of one year of storage, cell viability and CD34⁺ cell counts decreased significantly. The use of cord blood samples in capillaries, which can be easily stored for a long period, was similar to the methods used for testing segments attached to the cord blood unit.
Conclusions:
The results of this study may be useful for determining the period during which the quality of cryopreserved cord blood units used for transplantation is maintained.
