An alternative to dextran for the thawing of cord blood units

Abstract

Background: Preparation of umbilical cord blood units (CBUs) for infusion requires a step of dilution or washing to reduce the toxicity of the dimethyl sulfoxide present in the freezing solution. However, the worldwide shortage of clinical-grade dextran 40, the most widely used cord blood dilution or washing solution, prompted us to search for an alternative solution. We elected to evaluate the performance of alternative solutions that could be used as potential replacements for the dextran 40-based solution.

Study design and methods: Frozen CBUs were rapidly thawed and immediately diluted 1:4 in each of 10 dilution solution variants of dextran 40, Plasma-lyte, or Hespan. We compared these alternatives by assessing viability, CD34, CD45, and colony-forming units recovery postthaw.

Results: A significantly lower CD34 and CD45 recovery was observed in all solutions without human serum albumin (HSA). All solutions with 5% HSA gave recovery, viability, and potency figures similar to the dextran 40/HSA solution.

Conclusion: Based on our results and considering that Plasma-lyte A (PA)/HSA is already used for the thawing of CD34 from mobilized blood, we conclude that PA/HSA could be a safe and efficient solution for the replacement of dextran 40-based dilution solutions.