What happens to the cord blood once it is collected?
After the cord blood is collected, it is sent to the cord blood bank for processing, quality control testing, and storage. Processing procedures, quality control tests and storage procedures can vary from bank to bank.
How do processing methods differ?
An unprocessed cord blood unit contains different components, including plasma, red blood cells, white blood cells and stem cells.
Cryopreservation of ‘whole blood’ refers to freezing and storing the cord blood unit without removing any red blood cells or plasma.
Red blood cells have been associated with harmful or fatal side effects if too many of them are used in a transplant (FACT Spring 2013). This means that some of the red blood cells need to be removed from the unit before it can be used in a transplant, and this can be done before or after cryopreservation. ‘Red cell depletion’ (also called ‘red cell reduction’) refers to the removal of most of the red blood cells before cryopreserving the cord blood unit. Units stored without red cell depletion must be washed after they are thawed and before use in a transplant (FACT-JACIE Cellular Therapy Standards).
Plasma does not contain any stem cells. To reduce the space required for the storage of cord blood, plasma is removed before cryopreserving the unit, and this process is referred to as ‘volume reduction’.
Are cord blood collections ever rejected?
Yes. Both public and private cord blood banks may choose not to store the cord blood unit based on their acceptance criteria for cord blood quality. Public cord blood banks in the UK operate strict acceptance criteria, so that they can maximise the number of high quality cord blood units that can be banked. Acceptance criteria vary between private cord blood banks, but it is rare for a private cord blood bank to reject a cord blood unit if the family wishes to continue storage. Some banks will not store cord blood units if the mother’s blood tests positive for a disease such as HIV.
Where a privately-banked cord blood unit has been identified as not meeting a bank’s acceptance criteria, the reasons for this and any implications on the clinical usefulness of the cord blood should be discussed with the family. This will help the family to make an informed decision about continuing storage of the cord blood. If a bank decides to discontinue storage based on their own policies, the family is normally entitled to a full or partial refund according to the terms of the storage agreement.
In addition to storage for established transplant treatments, private cord blood banks market cord blood banking services for potential future uses, including clinical trials and stem cell therapies that have not yet been developed. Private cord blood banks should provide families with sound scientific and medical information to assist them in making informed choices about whether to store their cord blood for potential future uses yet to be investigated or proven.
Can rejected cord blood be used for research?
Cord blood rejected by a public or private cord blood bank can be used for research, but only if the mother has given her specific consent for this. Otherwise, the cord blood that is unsuitable for banking will be disposed of using normal hospital disposal procedures.