Finding a Match

Cord blood transplants do not need to be a perfect HLA match. However, patients have a better chance to survive and regain their health when the cord blood graft is a better match (6/6 or 5/6) and/or has a good cell dose (20 million nucleated cells per kg or more).

Public Preliminary Search (Open to Everyone).

Anyone, including patients and their families, can conduct a preliminary search to find the number of possible matches at the low resolution level of HLA typing. Physicians and Transplant Coordinators can submit formal Search Requests (based on high resolution HLA typing) online.

Transplant Center Formal Search.

When a formal Search Request is made, the NYBC's National Cord Blood Program provides the Transplant Center with a Preliminary Match Report. This Report lists individually all cord blood units available at low resolution HLA type, sorted by the level of HLA match and total nucleated cell (TNC) number. Because some patients still do not have high resolution HLA typing, the match is based on low resolution typing. High resolution DRB1 type of each unit is included in the report, however.

Cord Blood Unit Match Reports.

When the Transplant Center wants to select a cord blood unit, or units, for possible transplantation, the Transplant Coordinator requests Match Reports on each unit the physicians want to consider. An individual Match Report gives detailed information about the cord blood unit, including number of cells, ABO and Rh blood groups and results of other laboratory tests. NCBP staff also review the medical history records before the report is released to identify and report on any details that might affect the quality of the unit or potential risks for infectious or genetic diseases.

Confirmatory HLA Typing.

When a cord blood transplant is being seriously considered, we request a blood sample from the patient to confirm the patient's HLA type in our own laboratory. Confirmatory HLA typing of each unit also is completed using blood in a segment of tubing attached to the bag. This procedure both confirms the HLA type and assures that there was no mistake in labeling during processing. Confirmatory HLA typing is done at the high resolution level and by DNA sequencing and is generally available within 2-3 days (less than 24 hours in an emergency). Thus, final selection of the cord blood unit is based on the most rigorous HLA typing possible. We do not charge for confirmatory typing of either the patient or cord blood.

Nuclear Acid Tests (NAT) for Infectious Diseases.

When a cord blood unit is being seriously considered, we send an aliquot (a tiny sample) of the cord blood and the mother's blood for NAT testing for hepatitis C virus and human immunodeficiency virus (RNA) if this was not already done. If the mother was positive for antibody to the hepatitis B core antigen (anti-HBC) and is HBsAg negative, we send a sample for HBV-NAT (NAT for HBV-DNA is not yet licensed by the FDA). NAT results are generally available within 3-5 days.

Aliquots Available for Special Testing.

Transplant Centers can request aliquots of stored plasma, nucleated blood cells or DNA for special testing or we can send samples to a specific laboratory for special testing, at the Center's discretion. Centers have requested samples to measure enzyme levels for specific genetic diseases, for example, or for infectious agents that are not part of routine testing.

Unit Selection.

Preliminary data indicates that cord blood units with a 6/6 match to the patient's HLA type do best, regardless of TNC dose. When the match is 5/6 or less, TNC dose matters. In these cases, we recommend at least 20 million TNC per kilogram of the patient's body weight or higher. At present, there is no evidence that the outcome of the transplant is improved if the TNC dose is greater than 100 million.

NCBP staff assist in selecting the most appropriate unit available for the patient, depending on the HLA match and cell dose. NCBP scientists are available for consultation. If necessary, we will do special analyses of transplant outcome data to help make a decision in selecting a cord blood unit.

What Happens Next?

When a cord blood unit is requested for shipment, NCBP asks for a copy of the patient's signed consent form and asks the transplant physician to sign a Request Form documenting that he or she has reviewed all the information provided and approves the transplant. We require documentation of IRB approval of the transplant protocol and the patient's Informed Consent because we operate under an FDA IND exemption. All records of the unit and patient are reviewed by one of the NCBP Directors (Dr. Rubinstein or Dr. Stevens), who must give final approval to release the unit. NCBP staff then work with Transplant Center staff to schedule shipment of the unit to the Transplant Center.