Cord blood, as a source of progenitor cells, has been increasingly used in transplant procedures. However, transplant centers typically use cord blood units that have been processed and obtain by collection centers located elsewhere. This means that efficient cryopreservation procedures have to be in place for therapeutic use that lead to minimal cell loss. The key steps in cord blood banking include:
- Planning and preparation for cryopreservation
- Thawing at the transplant center
Typically, most cord blood banks assess potency, viability and hematocrit content prior to cryopreservation. Thawing of cord blood units after cryopreservation is often a tricky procedure, and one that may lead to the biggest variability in preserved cell viability.
Because thawing, washing and transfusion procedures vary among different centers, there has been an increasing call from the scientific community involved in this area for the standardization of these procedures across the industry.
A recent review paper published last month in Transfusion by Jeffrey McCullough and colleagues at the University of Minnesota reviewed current thawing practices performed across cord blood banks and identified inconsistencies among procedures before recommending elements to consider for more standardized thaw procedures across clinics.
Recommendations include decreasing thaw procedures and requiring validation of processing procedures at transplant labs as well as defining standards for processing. While comprehensive standards are currently not in place, there is an increasing need to provide more standardized approaches for the thawing of cryopreserved material. These recommendations are in addition to the standards for processing that organizations like FACT and AABB have have successfully put in place.
Colleagues in the field are echoing these recommendations set forth by Jeffrey McCullough’s manuscript. AABB and FACT have been called on to enhance inspection related to thawing/washing and transfusion and provide training related to these procedures. FACT has released guidelines with relation to administration of cord blood units. Similarly, AABB has been developing standards for blood banks and transfusion services since 1957.
For instance, AABB publishes Standards for Cellular Therapy Product Services which have formed the basis of AABB’s accreditation programs. Similarly, FACT-JACIE has published International Standards for Cord Blood Collection, Banking, and Release for Administration which can be found here. These, in addition to further initiatives aimed at providing guidelines to the industry, are laudable efforts on the part of FACT and AABB to achieve more comprehensive standardization across the industry. Numerous cord blood banks have been accredited for complying with FACT and AABB’s stringent cord blood banking guidelines.
The new recommendation is to apply the same efforts at providing standards for thawing, washing and transplantation.
New procedures that form the basis of the collective pool of scientific data are consistently appearing in the literature: just recently, a research paper was published outlining an improved procedure for the preservation of progenitor cells in preserved cord blood by storage at 4C prior to cryopreservation.
Whether such procedures can form part of cryopreservation approaches is part of the complexity of the assessment, validation and standardization procedure, and part of the reason why efforts in coming up with validated processes and unified standards have been challenging.
We are curious to hear about your experiences and thoughts about the issue of standardization of washing and thawing procedures for therapy. This is a subject that very much relies on user input, and the summary that we presented above all but scrapes the surface of the complexities of this problem. Nonetheless, we thought it worthwhile to draw attention to this issue so that we can begin this collective discussion. We welcome your thoughts as a comment on this blog or via email to firstname.lastname@example.org.