New Mexico has state legislation around cord blood education that only mandates/encourages physicians to educate expectant parents about public donation of cord blood. The New Mexico bill was enacted 19 Mar. 2005 and became effective 1 Jan. 2006.
- Processing: Must cord blood be processed before storage?
The earliest cord blood transplants were performed with whole cord blood. Thus, it is not absolutely necessary to process cord blood in order to save patient lives. There has never been a prospective randomized trial to compare transplant patient outcomes with cord blood that had been stored whole versus processed.
Most cord blood banks, both public and private, now process cord blood to remove both the plasma and the red cells, and cryo-preserve the remaining buffy coat holding stem cells. Some banks also save the removed red cells and plasma in companion storage. Some banks save a sample of maternal blood.
The removal of plasma is also called volume reduction. The volume reduction enables more collection units to fit in a freezer and requires less cryogenic nitrogen per unit.
Also, the majority of banks remove red blood cells prior to freezing, primarily because these cells often burst during freezing and release iron from hemoglobin that can be toxic. The alternate to removing the red cells before freezing is to wash any broken cells out of the collection upon thaw. Removing the red cells also removes the donor's blood type (the ABO and Rh types). When cord blood goes from a donor to a patient for a transplant, the donor and patient can be compatible on all the HLA types used for transplant matching and still have incompatible red blood types.
- How much cord blood is needed for a transplant?
The crucial thing is not the volume of the cord blood collection, but the number of stem cells it contains. Transplant doctors develop recommendations based on the Total Nucleated Cell count, or TNC, because it is the easiest measure to reproduce between different labs. For treating cancer, the transplant dose should be at least 25 million TNC per kilogram of patient body weight (1 kilogram equals 2.2 pounds). The average cord blood collection holds 8.6 million TNC per mL. Thus, the optimal transplant dose requires harvesting:
1.3 mL of cord blood for every pound of patient weight, -or-
2.9 mL of cord blood for every kg of patient weight
However, as more transplant centers are adopting the practice of giving adult patients "double cord blood transplants" with two cord blood units, it is less critical for both units to have adequate cell dose.
Reed, W et al., Blood 2003;101(1):351
Barker, JN et al., Blood 2005;105:1343-1347
Eapen, M et al. Lancet 2007;369:1947-54
Rocha & Gluckman Brit. J. Haematology 2008;147:262-274
Delaney, C et al., Brit. J. Haematology 2009;147:207-216
Michallet et al. 2010 Blood 2010;116:Abstract#361
- What questions should parents ask a Family Bank about Laboratory Standards?
- Is the cord blood laboratory accredited by an agency that has specific standards for cord blood banks and conducts inspections? (ex: AABB, FACT, ISO)
- Some US states license cord blood banks (CA, MD, NJ, NY): Do they operate in those states? Note that the California Biologics License is based on AABB accreditation, but lags behind the latest AABB updates.
- Does the lab process cord blood around the clock, or only on selected shifts?
- What tests does the lab perform on maternal blood?
- What tests does the lab perform for infectious disease markers?
- What tests does the lab perform for contamination?
- Does the lab ever reject cord blood collections on the basis of the tests of maternal blood, infectious diseases, or contamination?
- Does the lab maintain a "quarantine tank" for the storage of blood that might be able to transmit an infection?
- What tests does the lab perform to measure the stem cell count of the processed cord blood and the stem cell viability?
- Does the lab/bank inform parents, prior to storage, if the collection is too small for a transplant, and give them the option not to save it?
- Does the lab/bank offer parents a refund if the cord blood collection has certain problems (contamination, low volume)? These refunds are typically only offered if the bank performed the collection as part of their service.
- What information will parents receive in the final report about their stored cord blood?