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Cord blood bank
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A cord blood bank is a facility which stores umbilical cord blood for future use. Both private and public cord blood banks have developed since the mid to late 1990s in response to the potential for cord blood transplants in treating diseases of the blood and immune systems. However, cord blood is not recommended to be stored in a private bank for the vast majority of cases.
Public banks accept donations to be used for anyone in need.
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Encyclopedia
A cord blood bank is a facility which stores umbilical cord blood for future use. Both private and public cord blood banks have developed since the mid to late 1990s in response to the potential for cord blood transplants in treating diseases of the blood and immune systems. However, cord blood is not recommended to be stored in a private bank for the vast majority of cases.
Public banks accept donations to be used for anyone in need. Unlike private cord blood banking, public cord blood banking is supported by the medical community. However, there are very strict regulations which public banks need to follow in order to enable the donated units to be added to a registry. Generally an expectant mother interested in donation should contact the bank before the 34th week of pregnancy. The National Marrow Donor Program has a list of public cord blood banks on their website. Once the blood is donated, it loses all identifying information after a short period of initial testing. Families are not able to retrieve their own blood after it has been donated, but as discussed below it is very unlikely that they would be able to use the sample themselves.
Private or family banks are subject to current FDA and state regulations. It is recommended that private cord blood banks apply for optional accreditation by the AABB (formerly the American Association of Blood Banks), which requires a bi-annual audit to ensure that the bank follows their quality assurance guidelines.
Private banks have been criticized for aggressive and misleading marketing campaigns to expectant parents. Most private banks charge a fee of around $1000-$2000 to preserve the harvested cord blood for biological insurance.
Cord blood contains hematopoietic stem cells, progenitor cells which can form red blood cells, white blood cells and platelets. Cord blood cells are currently used to treat blood and immune system related genetic diseases, cancers and blood disorders. Medical critics of routine cord blood collection emphasize that if neonatal cord blood is so physiologically valuable, it is of great benefit for the neonate to receive upon birth.
The collection process
Cord blood collection happens after the umbilical cord has been cut and is extracted from the placental end of the cord, diverting up to 180ml (an average of 100mL) from the neonate, the equivalent of half its total blood volume at a highly sensitive developmental time.
Additional stem cells may be collected from the placenta via Placenta Cord Banking. After the health care provider draws the cord blood from the placental end of the umbilical cord, the placenta is couriered to the stem cell laboratory where it is processed for additional stem cells.
An adequate cord blood collection requires at least 75 mL in order to ensure that there will be enough cells to be used for a transplantation. After the collection, the cord blood unit is shipped to the lab and processed and then cryopreserved. There are many ways to process a cord blood unit and there are differing opinions on what is the best way. Some processing methods separate out the red blood cells and remove them while others keep the red blood cells. However the unit is processed, a cryopreservant is added to the cord blood to allow the cells to survive the cyrogenic process. After the unit is slowly cooled to -90 Celsius it can then be added to a liquid nitrogen tank which will keep the cord blood unit frozen at -196 Celsius. The slow freezing process is important to keep the cells alive during the freezing process. Before the blood is stored for later use, it undergoes viral testing, including tests for HIV and Hepatitis B and C and tissue typing (to determine HLA type).
Benefits of Banking Cord Blood
Cord blood stem cells are currently used in the treatment of several life-threatening diseases, and play an important role in the treatment of blood and immune system related genetic diseases, cancers, and blood disorders.
The first clinically documented use of cord blood stem cells was in the successful treatment of a six-year-old boy afflicted by Fanconi anemia in 1988. Since then, cord blood has become increasingly recognized as a source of stem cells that can be used in stem cell therapy.
Recent studies have shown that cord blood has unique advantages over traditional bone marrow transplantation, particularly in children, and can be life-saving in rare cases where a suitable bone-marrow donor cannot be found. Approximately 50% of patients requiring a bone marrow transplant will not find a suitable donor within a critical period. In certain instances there may be some medical issues around using one's own cord blood cells, as well as availability of cells, which will require treatments done using cells from another donor, with the vast majority being unrelated donors. However, studies have shown that cord blood stem cells can also be used for siblings and other members of your family who have a matching tissue type. Siblings have up to a 75% chance of compatibility, and the cord blood may even be a match for parents (50%) and grandparents.
Issues common to all cord blood banks
The main concern of cord blood banking, private or public, is the long-term viability of cryogenically frozen cord blood, although studies have shown that the cord blood can be cryogenically frozen indefinitely.
Other established treatments may be more suitable for the patient, rather than cord blood transplants, and it may become possible to obtain the needed blood or more generalized stem cells by other means, such as from the bloodstream of an adult or from tissue culture.
Different Banking Methods
The FDA governs the collection, processing, storage, labeling, packaging and distribution of cord blood stem cells. There are two different standards which can apply: cGTP (current Good Tissue Practices) and cGMP (current Good Manufacturing Practices). cGTP standards apply to the collection, processing and storage of human cells, tissues and cellular/tissue based products (HCT/Ps) and are regulated by the Center for Biologics Evaluation and Research. All US cord blood banks must be compliant with cGTP standards. cGMP standards apply to the manufacture of a product that is considered a drug. How one determines if a bank must be compliant with cGMP standards is based upon the product that they manufacture. If a cord blood bank manufactures cord blood stem cells that are overly manipulated or the cells are used in a different basic biologic function that product is regulated as a drug and both cGTP and cGMP standards would apply. If a cord blood bank manufactures cord blood stem cells that are minimally manipulated and the cells are used for the same basic biologic function and/or for use in people that are 1st or 2nd degree blood relatives, that product is regulated solely under cGTPs.
cGTP standards are based upon cGMP standards and thus there are many similarities.
Public bank
A primary concern with public banking is how to ensure the safety of the cord blood. Because of privacy concerns, it is agreed by most ethical review boards that blood donated to a public bank cannot be permanently linked to the donor. Although cord blood which is donated goes through a series of tests for potentially harmful genetic disorders and viruses, some genetic disorders such as congenital anemias or immunodeficiencies might not become apparent in the donor for months or years, by which time all identifying information has long been removed. Because the recipient of the blood could also develop these disorders, this is an important concern.
The larger obstacle facing public banks is that the high costs required to maintain them has prevented more than a handful from opening. Because public banks do not charge storage fees, many medical centers do not have the funds required to establish and maintain them.
Because of donation patterns, differing racial groups have different likelihood of finding a match through a public cord blood bank. Caucasians find a match 88% of the time, while other races match just 58% of the time. Public bank advocacy groups are particularly trying to encourage donations by members of non-Caucasian racial groups.
It is also important to note that families who donate their child's cord blood to public banks are not assured their samples will be banked or would be available to them if required at a later date.
Private bank
Private banking is costly to insurers and private parties, averaging $2500. The ability to use the cord blood may also depend on the long-term commercial viability of the enterprise. Accordingly, whether cord blood banking is a worthwhile expenditure for the expectant parent depends in part upon whether the expenditure is offset by the likelihood of ultimately using the cord blood and the benefits of such use.
Some cord blood banks are publicly traded on a stock exchange and perform research, claiming that this makes them more trustworthy; however, such activities do not directly benefit patients.
It is important to ensure the credentials of any potential private bank. For example, in the UK private banks are accredited by the Medicines and Healthcare Products Regulatory Agency and Human Tissue Authority. Cord Blood Banks in Canada must meet Health Canada Standards and are accredited by the American Association of Blood Banks.
Likelihood of use
The likelihood of using cord blood in private banks has rested mostly on the odds that the donor child or a family member will require a stem cell transplant. In the United States, the lifetime probability (up to age 70) that an individual will undergo an autologous transplant of their own stem cells is 1 in 435, the lifetime probability to undergo an allogeneic transplant of stem cells from a donor (such as a sibling) is 1 in 400, and the overall odds of undergoing any stem cell transplant is 1 in 217 These figures are based on actual transplant rates in 2001-2003.
Cord blood transplants require less stringent matching between the tissue types of the donor and patient, known as their HLA types . Bone marrow transplants require a complete match on six key antigens which are measures of graft-versus-host reaction, known as a 6/6 match. Cord blood transplants achieve the same medical success with only a 4/6 match. HLA type is inherited from both parents, so siblings are particularly likely to be a match, and people from the same ethnic heritage are more likely to match. Minority ethnic groups have difficulty finding a perfectly matched transplant donor; for them, the ability to transplant partially-mismatched cord blood opens access to transplant therapy. he Stem Cell Act of 2005 mandated HRSA to fund public cord blood banks to recruit more cord blood donations from ethnic minorities .
Studies have found that allogeneic transplants have better outcome when the donor and patient are related (because in addition to those six key antigens, so many other antigens match). The odds that two siblings will have the 6/6 match required for a bone marrow transplant are 25%. The odds that two siblings will have the 4/6 match required for a cord blood transplant are 39%.
Legality and ethics
For those at low risk, private storage of one's own cord blood is unlawful in Italy and France, and discouraged in some other European states.
In 2004, the European Group on Ethics in Science and New Technologies advised the European Commission that "The legitimacy of commercial cord blood banks for autologous [self] use should be questioned as they sell a service, which has presently, no real use regarding therapeutic options. Thus they promise more than they can deliver. The activities of such banks raise serious ethical criticisms."
Some doctors and patients have stated that the claims of some private cord blood banks are deceptive and misleading.
Controversy Among Medical societies
The Royal College of Obstetricians and Gynaecologists 2006 opinion states, "There is still insufficient evidence to recommend directed commercial cord blood collection and stem-cell storage in low-risk families."
The policy of the Society of Obstetricians and Gynaecologists of Canada (SOGC) supports public cord blood banking (similar to collection and banking of other blood products- ie- altruistic, anyone can use it) as well as stating it should be considered under certain circumstances. "ref name= SOGC Clinical Practice Guidelines, No. 156, March 2005. Umbilical Cord Blood Banking: Implications for Perinatal Care Providers"/> http://www.sogc.org/guidelines/public/156E-CPG-March2005.pdf
The policy of the American Academy of Pediatrics policy states that "private storage of cord blood as 'biological insurance' is unwise" unless there is a family member with a current or potential need to undergo a stem cell transplantation.
Similarly, the American College of Obstetricians and Gynecologists does not recommend private cord blood banking.
Private storage of one's own cord blood is unlawful in Italy and France, and discouraged in some other European states. the American Academy of Pediatrics states that private cord blood banking is generally not recommended unless there is a family history of specific genetic diseases.
The states that public donation of cord blood is encouraged where possible, the probability of using one's own cord blood is very small, and therefore storage of cord blood for personal use is not recommended and family member banking (collecting and storing cord blood for a family member) is recommended when there is a sibling with a disease that may be treated successfully with allogeneic transplant.
Safety and effectiveness of using one's own cells unclear
Using one's own cord blood cells might not be wise or effective, especially in cases of childhood cancers and leukemia. Children who develop an immunological disorder often are unable to use their own cord blood for transplant because the blood also contains the same genetic defect. Nearly all of the transplants using privately banked cord blood have gone to relatives with pre-existing conditions, not to the donors.
Additional issues include the possibility contamination of the cord blood unit with the same cancer diagnosed later in life-- for example, abnormal cells have been detected in filters containing newborn blood of children who were not diagnosed with acute leukemia until the age of 2 to 6 years. The high relapse rates after autologous or syngeneic tranplant and the benefit of a graft-vs.-leukemia effect of an allogeneic transplant suggest that autologous cord blood would not be the ideal source of stem cells for patients with leukemia needing a transplant.
Usability of one's own sample unknown
Most cord blood samples - up to 75% - may be too small to be used for transplantation, because they don't contain enough stem cells. While a private bank will store a sample, the sample may be too small to be usable even by a child. Larger numbers of blood cells are required for adults, due to their larger body mass.
Ownership of cord blood unclear
As of 2007, contracts of the largest cord blood banks do not explicitly state that the cord blood belongs to the donors and child with all the rights and privileges one would reasonably expect from ownership. The ambiguity leaves open future uses not approved by the donors and child. Examples of possible uses without the donor's consent include cloning, research, or partial sale. Some contracts fail to spell out the rights of the donors requesting termination of storage: e.g. the right to request and verify destruction of the samples.
Medical issues
Concerns have been raised that the current interest in cord blood could cause a perception that cord blood is 'unused' by the birth process, thus decreasing the amount of blood which is infused into the child as part of the birth process. The pulsation of the cord pushes blood into the child, and it has been recommended that the cord cease pulsation prior to clamping. With the demand for cord blood increasing, there is a possibility that the cord could be clamped prematurely to preserve even more 'extra' cord blood. This action could have detrimental effects on the child's future development.
The American Academy of Pediatricians notes: "if cord clamping is done too soon after birth, the infant may be deprived of a placental blood transfusion, resulting in lower blood volume and increased risk for anemia."
The Journal of the American Academy of Pediatrics published an article in April 2006 recommending that clamping be delayed to reduce anemia and improve neonatal iron storage.
Confusion with embryonic stem cells
Much of the general public in the United States is somewhat aware of embryonic stem cells because of the controversy associated with them. However, cord blood stem cells (hematopoietic stem cells) are not embryonic stem cells (pluripotent stem cells).
Sources
- Cairo, Mitchell S. and John E. Wagner, "Placental and/or Umbilical Cord Blood: An Alternative Source of Hematopoietic Stem Cells for Transplantation," The Journal of The American Society of Hematology 90:4665-4678 (1997)
- Kline, Ronald M., "Whose Blood is it, Anyway?", Scientific American 284: 42-49 (April 2001)
- Kline, Ronald M., and Salvatore Bertolone, "Umbilical Cord Blood Transplantation: Providing a Donor for Everyone Needing a Bone Marrow Transplant?", Southern Medical Journal 91: 821-827 (1999)
See also
External links
- — A non-profit organization about cord blood banking.
- — The NHS Cord Blood Bank
- , Parents' magazine, April 2006
- , which argues that private cord blood banking is not an effective use of money.
- — Umbilical Cord Issues
- — A non-profit public cord blood donation and education foundation
- The New Jersey Cord Blood Bank (NJCBB)
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