Rhode Island has state legislation around cord blood education that follows the Institute of Medicine guidelines and mandates/encourages physicians to educate expectant parents about ALL forms of cord blood banking. The Rhode Island bill was enacted 27 June 2008 and became effective 27 June 2008.
- 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.
- Processing: How is cord blood processed before storage?
The three main components of cord blood, like any blood collection, can be separated by weight: the heaviest layer is the red blood cells (RBC), the lightest is the plasma (a clear white liquid), and in the middle is a pinkish layer called the "buffy coat" which contains the white blood cells (WBC), including stem cells. When banks process the cord blood, the final separated component that goes into storage is the buffy coat, even though only about 1% of the cells are actually stem cells. There is no procedure to separate out the stem cells alone.
The vast majority of blood processing methods rely on the different density of the three main blood components. They can be separated by sedimentation, or by centrifuge, or by a combination of the two techniques. The procedure can be performed manually by trained technicians or by automated machine.
- Once we have stored cord blood for our family, how long should we keep it?
- Indefinitely. From an economic perspective, it does not make sense to invest in the up-front processing fee and pay for years of annual storage, and then throw out the investment. That would be like buying life insurance and then cancelling it because you have not died yet. Especially given that the probability of some one in the immediate family needing a transplant increases with age. Even if the cord blood collection was small, and the child becomes too large to use it for a transplant, it could still be enough cells for a regenerative medicine therapy. The science of cryobiology tells us that cells which are cryogenically preserved remain viable for decades. It has been confirmed that cord blood stem cells were still viable after being frozen 23+ years.
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