How transplant centers deal with the dextran shortage: recommendations for comparing alternatives.

BACKGROUND: In the United States, dextran 40 in 0.9% NaCl is the preferred reagent for the thawing and preparation of cord blood units for hematopoietic stem cell transplantation. The recurring nationwide shortage of this reagent could have implications that extend to the avoidance of cord blood for transplantation. STUDY DESIGN AND METHODS: To address the shortage, the National Marrow Donor Program and its Cord Blood Advisory Group sought to identify available alternative reagents or manufacturers. A sample of transplant centers (TCs) were surveyed to determine their process to compare these alternatives. The TCs were then asked to share their comparability protocols for review. RESULTS: The 12 TCs that responded to the survey studied various types of alternative reagents and manufacturers of the standard dextran 40 in 0.9% NaCl. Four TCs submitted their protocols from which a model comparability protocol was created for centers who need assistance. CONCLUSION: Whether comparing dextran 40 in 0.9% NaCl to that of a different manufacturer or a different reagent, the results of the comparability studies submitted by the TCs indicated equivalency. During a shortage, the model comparability study protocol can be used as a reference to establish an alternative to dextran 40 in 0.9% NaCl.

How we handled the dextran shortage: an alternative washing or dilution solution for cord blood infusions.

Dextran 40 is the main component of the solution used to wash or dilute thawed cord blood unit (CBU) products for stem cell transplant. Dextran 40 became unavailable in the United States as of April 2014. Like many other cellular therapy laboratories in the United States, we found ourselves with limited dextran 40 inventory, a growing CBU transplant requirement, and no alternative solution. Since there are no published alternative washing solutions for cryopreserved CBU we had to develop and validate a new solution rapidly. We chose to validate hydroxyethyl starch (HES) due to its similar ability to stabilize red blood cells and reduce sudden changes in osmolality that occur during thawing. For the validation we used 3 CBUs and thawed and washed each unit with both dextran 40- and HES-based solutions; thus, each CBU served as its own control. We observed no significant differences between the two wash solutions for all the monitored variables including cell viability, cell recovery, or potency measured by colony-forming cell assay. Based on this initial validation we began using HES-albumin for CBU washing after our supply was exhausted. Our initial experience with the first 16 CBU transplants after validation indicates safe infusion and preliminary cord engraftment.