Cord blood bank
|This article does not cite any references or sources. (July 2013)|
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 in treating diseases of the blood and immune systems.
Public banks accept donations to be used for anyone in need. The percentage of public bank donations discarded as medical waste is estimated to be between 60 to 80%. Traditionally, public cord blood banking has been more widely accepted by the medical community in part because paying to save the cord blood privately is not financially feasible for many families. 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. Once the blood is donated, it loses all identifying information after a short period of initial testing. Families are not able retrieve their own blood after it has been donated.
Banking cord blood in a private umbilical cord blood bank, such as Cord Blood Registry or Americord Registry, is a personal choice made by both parents. Private banks store cord blood with a link to the identity of the donor, so that the family may retrieve it later if it is needed. The parents have custody of the cord blood until the child is an adult. The cord blood might someday be needed by the donor baby, or it could be used by a relative who is a close enough match to receive a transplant from the donor, typically a sibling. Private banks charge a fee to preserve the harvested cord blood for family 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.
In the United States, the Food and Drug Administration regulates cord blood under the category of “Human Cells, Tissues, and Cellular and Tissue Based-Products.” The Code of Federal Regulations under which the FDA regulates public and private cord blood banks is Title 21 Section 1271. Several states also require accreditation, including New York, New Jersey, and California. Any company not accredited within those states are not legally permitted to collect cord blood from those states, even if the company is based out of state. Potential clients can check the New York accreditation status from the New York Umbilical Cord Blood Banks Licensed to Collect in New York. Both public and private cord blood banks are also eligible for voluntary accreditation with either the American Association of Blood Banks AABB or the Foundation for the Accreditation of Cellular Therapy FACT. Potential clients can check the current accreditation status of laboratories from the AABB list of accredited cord blood laboratories (note that several companies, such as Americord Registry, have AABB laboratories listed under different names) or the FACT search engine of accredited cord blood banks (on their home page). Other countries also have regulations pertaining to cord blood.
Cord blood collection happens after the umbilical cord has been cut and is extracted from the fetal end of the cord, diverting up to 75 +/- 23 mL from the neonate. It is usually done within ten minutes of giving birth.
Additional stem cells may be collected from the placenta. 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 75mL in order to ensure that there will be enough cells to be used for a transplantation.
Before the cord blood is stored for later use, it undergoes viral testing, including tests for HIV and Hepatitis B and C, and tissue typing to determine Human Leukocyte Antigen type. It will also be examined for nucleated cell count, cell viability, blood group antigen ABO & Rh blood group system, molecule cluster (CD34), and bacterial and fungal growth.
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 cryogenic process. After the unit is slowly cooled to −90°C, it can then be added to a liquid nitrogen tank which will keep the cord blood unit frozen at −196°C. The slow freezing process is important to keep the cells alive during the freezing process. There is no consensus yet on optimal procedures for these cord blood cells, although many cryopreservation strategies suggest using dimethyl sulfoxide (DMSO), slow or controlled rate cooling, and rapid thawing.
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. Cord blood stem cells can also be used for siblings and other members of your family who have a matching tissue type. Siblings have a 75% chance of compatibility, and the cord blood may even be a match for parents (50%) and grandparents.
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[who?] that blood donated to a public bank cannot be permanently linked to the donor[dubious ]. 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 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 banking is costly to insurers and private parties, averaging. 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 by the benefits of such use.
It is important to ensure the credentials of any potential private bank. In the United States, the Food and Drug Administration regulates cord blood under the category of “Human Cells, Tissues, and Cellular and Tissue Based-Products”.
Cord blood transplants require less stringent matching between the tissue types of the donor and patient, known as their HLA types Human leukocyte antigen. 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.
Studies have found that allogeneic transplants have better outcome when the donor and patient are related. 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%.
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, i.e. altruistic, anyone can use it), as well as stating it should be considered under certain circumstances.
The policy of the American Academy of Pediatrics 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. However, this opinion is over 10 years old and authored by Dr. Joanne Kurtzberg and does not account for recent therapeutic uses and research. Dr. Joanne Kurtzberg now publicly supports public and private cord blood banking. Private storage of one's own cord blood is unlawful in Italy and France due in part to conservative views on stem cell and genetic research, and it is also discouraged in some other European countries.
The American Society for Blood and Marrow Transplantation 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
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.
Additional issues include the possible 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 transplant 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 cell. 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 because of their typically larger body mass.
Ownership of cord blood
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.
The majority of private cord blood banking facilities, the mother owns all rights to the cord blood that was banked, until the minor in which the cord blood was taken turns eighteen. At that time the minor has all rights to his or her own banked cord blood.
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.
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.
Confusion with embryonic stem cells
The public in the United States has a general awareness of embryonic stem cells because of the stem cell controversy. However, cord blood stem cells (hematopoietic stem cells) are not embryonic stem cells (pluripotent stem cells).