Cord blood bank

From Wikipedia, the free 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.[1][2][3] 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 of course 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 banks are highly unregulated and 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. Current estimates place the likelihood of a child using her or his own cord blood at only greater than 1 in 2500 before the age of 20, and greater than 1 in 450 by the age of 70.

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.

Contents

[edit] 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).

[edit] Benefits of Banking Cord Blood

Cord blood stem cells are currently used in the treatment of over 40 life-threatening diseases, and play an important role in the treatment of blood and immune system related genetic diseases, cancers, and blood disorders.[4]

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.

[edit] 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[5] or from tissue culture.

[edit] Different Banking Methods

The FDA governs the collection, processing, storage, and clinical use of cord blood stem cells. There are two levels of standards which apply: cGTP and cGMP. All cord blood banks must be compliant with cGTP standards. Most cord blood banks in the USA are satisfied with cGTP compliance because current therapies such as stem cell transplantation using cord blood stem cells are simple enough they fall within the cGTP category.

The higher cGMP standard, however, is required for more complex cell therapies presently in clinical trial and being developed as future therapies such as those in current clinical trails for Alzheimer’s, Multiple Sclerosis, Diabetes, spinal cord injury, Lupus, and many other diseases.

Of course cord blood stem cells banked under cGTP are perfectly suitable for today's therapies, such as stem cell transplantation. But many are now adopting the belief that cGMP-compliant cord blood banking will be critical to the use of these stem cells in many of the more complex future therapies presently being developed. The FDA has recently made several statements which appear to support this point.

There are now a small number of leading-edge cord blood banks which require all their cord blood units to be banked in cGMP compliance.

[edit] 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.[6] 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.

[edit] 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.[3] 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.

[edit] Low likelihood of use

Cord blood is "very unlikely ever to be used" by the donor.[3] Estimates of the odds of using banked cord blood range from 1:2,700 to 1:20,000.[1] "According to research in the Journal of Pediatric Hematology/Oncology (1997, 19:3, 183-187), the odds that a child will need to use his or her own stem cells by age twenty-one for current treatments are about 1:2,700, and the odds that a family member would need to use those cells are about 1:1,400."[7] The likelihood of use for those lacking a family history of specific genetic diseases is much lower than the average across the entire population. A 2005 article states, "The probability of needing an autologous transplant is less than one in 20,000, although commercial providers quote figures at least an order of magnitude higher, often confusing prearranged usage in at risk children with unanticipated use in those at low risk." One of the reasons for low likelihood of use is that effective alternative treatments are available.[3]

A familial relationship does not ensure a match allowing transplant, as genetics vary. Even between siblings, there is a 25% chance that the cord blood will not be suitable, and a 50% chance it will be a partial match.[6]

[edit] 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.[1][6]

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."[8]

Some doctors and patients have stated that the claims of some private cord blood banks are deceptive and misleading.[9][10][6]

[edit] 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."[1]

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.[2]

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.[1][2][3] 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.[6]

The American Society for Blood and Marrow Transplantation (ASBMT) 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.

[edit] 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.[11] 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.[6]

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.[12]

[edit] 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.[6] 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.

[edit] 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.

[edit] 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.[13]

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."[2]

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.[14]

[edit] 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).

[edit] References

  1. ^ a b c d e Parents Guide (PDF)
  2. ^ a b c d AAP: CORD BLOOD BANKING FOR FUTURE TRANSPLANTATION NOT RECOMMENDED Press Release
  3. ^ a b c d e Can Routine Commercial Cord Blood Banking Be Scientifically and Ethically Justified?
  4. ^ See cord blood for a list of treated diseases, or visit the National Donor Marrow Program website
  5. ^ Serendipity in lab turns blood into stem cells
  6. ^ a b c d e f g Blood Pressures: The Controversy Over Cord Blood
  7. ^ Cbr Systems, Inc. (2006). Common Misconceptions About Cord Blood Banking. Cord Blood Registry. Retrieved on September 20, 2006.
  8. ^ [1] (PDF)
  9. ^ IS IT WORTH BANKING YOUR BABY'S CORD BLOOD? - Doctors say hard sell of hope is deceptive
  10. ^ Law Annoys Private Cord Banks
  11. ^ Medical References: Umbilical Cord Blood
  12. ^ Ballen et al ASBMT Committee Report: Collection and Preservation of Cord Blood for Personal Use BBMT 14: 356 - 363, 2008
  13. ^ See the websites: www.cordclamping.com and www.gentlebirth.org
  14. ^ The Effect of Timing of Cord Clamping on Neonatal Venous Hematocrit Values and Clinical Outcome at Term: A Randomized, Controlled Trial

[edit] 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)

[edit] See also

[edit] External links

Languages