Cord blood banking
- Donor Selection
- Preparation of Cord Blood
- Quality Control and Quality Assurance
- Step-by-step Guide to Reservation and Shipping a Unit of Cord Blood
The first successful sibling cord blood transplant for Fanconi´s anaemia in 1989 paved the way for other sibling and unrelated transplants. There have now been over 2,000 unrelated and related donor cord blood transplants performed worldwide. These have demonstrated the efficacy of cord blood transplantation, even in cases where there is incomplete tissue type matching between donor and recipient. Cord blood is a good alternative to other stem cells for adults and children with malignant and non-malignant disease. Unrelated cord blood transplants result in good outcome in children transplanted in remission and with inborn errors and immune deficiencies.
The NBS´ policy to collect cord units from the ethnic minorities has resulted in 42% of the cord blood donations deriving from these groups compared to 2% in the British Bone Marrow Registry and 8% in the Anthony Nolan Registry.
Cord blood is banked from donors whose mothers have met the Cord Blood Bank donor selection criteria, including microbiological screening tests for markers of transmissible diseases. It is a regulatory requirement that the mother be screened for HIV1 & HIV2, HBV, HCV and syphilis from a sample taken at the time of collection or within 7 days after delivery. Decisions on donor assessment are consistent with the following:
- UKBTS/NIBSC Medical Assessment of Donors of Tissues (MAD-T)
- UKBTS/NIBSC Guidelines for the Blood Transfusion Services in the United Kingdom
- Department of Health – Tissue Banks: Code of Practice
- Guidance on the Microbiology Safety of Human Organs, Tissues and Cells used in Transplantation (MSBT)
- Netcord/FAHCT International Standards for Cord Blood Collection, Processing, Testing, Banking, Selection and Release.
Preparation of Cord Blood
Collection takes place at selected hospitals where ethics permission has been granted and a service level agreement is in place. The cord blood is collected aseptically by trained staff within the delivery unit. All donor mothers are interviewed to obtain informed written consent for the use and testing of the donation and to determine whether the mother complies with the donor selection criteria.
Cord blood is stored for a maximum of 24 hours prior to processing. Processing to reduce the volume of cord blood involves depletion of plasma and red cells, using an automated component extractor, leaving only the buffy coat component for cryopreservation. Samples are removed throughout the process for testing, quality monitoring and archiving.
The cord blood buffy coats are cryopreserved in a final concentration of 10% DMSO, vacuum packed into secondary bags and frozen using a controlled rate freezing machine. Storage of the donation, with an integral sample sealed in the tubing, and a separate sample in a cryovial is in the gas phase above liquid nitrogen. All storage dewars are fitted with 2 temperature probes that are monitored continuously.
On completion of medical review and quality release the donations are made available for search. Prior to issue for transplant the suitability of the cord blood unit for the patient is assessed by a Medical Consultant, confirmatory testing is performed and additional testing as required by the Transplant Centre.
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- Representative samples of the final product are bacteriology screened by an accredited laboratory
- A nucleated cell count is performed before and after processing
- All processing is carried out in facilities compliant with GMP (Rules and Guidance for Pharmaceutical Manufacturers and Distributors)
- The product is subject to independent final release
Cord blood is transported at less than –135°C in dry shippers, validated to maintain the required temperature for at least 48 hours beyond the expected time of arrival at the receiving facility. The dry shipper contains a device that monitors the temperature throughout the shipment period.
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- additional and confirmatory HLA typing as requested
- Additional and confirmatory infectious disease screening:
Anti-HBc and anti-HTLV screening and nucleic acid testing for HIV and HCV performed on both maternal and cord blood samples at time of reservation or retesting on a sample obtained from the donor mother at least 180 days after delivery
CMV PCR performed on the cord blood sample
Additional organisms screened for as considered relevant by the NHS Cord Blood Bank
- VNTR analysis to compare a sample extracted from the bleedline of the frozen cord blood unit with the previously tested cord blood DNA sample
- CFU assay performed on a sample extracted from the bleedline of the frozen cord blood unit
- Loan of a dry shipper (if required)
This charge does not cover:
- Additional organisms that may be screened for as specified by the Transplant Centre
- Transport of the unit to the Transplant Centre
- Return of the dry shipper, if borrowed.
- The Transplant Centre completes a BBMR "Search Request Form"
- The completed form is sent to the BBMR Office
- The BBMR conducts a search and sends a preliminary "Search Report Form" to the Transplant Centre
Step 2. Obtain further information on the unit of interest
- The Transplant Centre returns the "Search Report Form" to BBMR who arrange for confirmatory typing and any further information requested. This may include additional HLA typing.
- The Cord Blood Bank arranges for a full review of the relevant donor file, providing a report to the Transplant Centre with a summary of all available data and information, and a "Reservation form".
- When requested, the HLA-A, B, DR type will be confirmed and high resolution typing performed. The results are sent directly to the Transplant Centre. HLA typing of the mother will also be performed on all reserved units.
Step 3. Reserve a unit
- Submit a completed "Reservation Request" form
- The unit will then be reserved for six weeks. Reservation must be reconfirmed monthly thereafter by FAX
- A letter is sent from the Cord Blood Bank to the Transplant Centre confirming reservation and explaining procedures and arrangements for delivery of the unit. The Cord Blood Bank recommends that the post thaw unit be washed prior to infusion; a copy of the Thaw and Wash protocol is included along with a "Request to Ship Unit" form
Step 4. Confirmatory infectious disease screening
- Retesting for the mandatory markers before issue of the cord blood unit is performed by one of two methods:
Resampling the donor mother at least 180 days after delivery
Performing nucleic acid testing for HIV and HCV on the mother´s original sample collected at the time of delivery and on a sample from the cord blood unit
- Samples are tested for anti–HBc and anti–HTLV I/II
- The cord blood unit is tested by PCR for CMV
- Additional organisms may be screened for when considered relevant by the Cord Blood Bank or as requested by the Transplant Centre
Step 5. A clinical report is compiled and sent to the Transplant Centre
- The completed "Donor File" is reviewed for release by a medical Consultant
- A "Clinical Report" is then compiled by the medical Consultant and sent to the Transplant Centre
Step 6. Proceed to transplant the reserved unit
- The "Request to Ship" form is FAXed from the Transplant Centre. This form is used to provide details of the proposed transplant and shipment dates, the courier, and contacts for receipt of the cord blood unit and for invoicing
- VNTR analysis is performed to compare a sample extracted from the bleedline of the frozen CB unit with the previously tested cord blood DNA sample
- The unit is dispatched at the appropriate time using a reputable courier
- The following documents accompany the donation:
Further copy of the ´Thaw and Wash´ procedure
Copy of completed Order/Issue form
- Instructions for the provision of clinical follow-up information using the registration and 3–month follow up forms as supplied
- A FAX is sent to the Transplant Centre to confirm the courier has collected the unit
- The Transplant Centre confirms arrival of the unit
Step 7. Cancel reservation if the unit is no longer required
- The Transplant Centre advises the Cord Blood Bank by FAX