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Umbilical cord blood is a very good source of stem cells, and these blood stem cells are useful in the treatment of many blood disorders and cancers.
The placenta, umbilical cord and the blood within it are very important in pregnancy. However, the blood serves no purpose after delivery if discarded. Umbilical cord blood is a very good source of stem cells. The blood can be collected after delivery with no risk to the baby or mother. These blood stem cells (BSC) are proven to be useful in the treatment of many blood disorders and cancers.
Blood Stem Cells (BSC) from cord blood can be harvested from the umbilical cord after delivery of your baby and clamping of the cord. A small needle is then inserted into the umbilical cord after adequate sterilisation. The cord blood with the BSC is then drawn out. This process will not hurt you or your baby.
The cord blood is then processed in the laboratory where a specific layer of cells containing the BSC will be extracted. A cryopreservative is then added before placing in liquid nitrogen tanks at approximately –180 degrees Celsius.
BSC are immature cells that are found in the bone marrow and peripheral circulation of an adult. The blood of the umbilical cord (cord blood) also contains large amounts of these cells. They can grow and mature into red cells, white cells and platelets.
BSC are different from embryonic stem cells. There are no ethical issues with BSC as no one is harmed with the harvesting of BSC from the umbilical cord. In fact, these BSC will become waste products if not harvested and stored.
Since the 1960s, BSC has been used for stem cell transplants (SCT), also called Bone Marrow Transplant (BMT) in the past as BSC were harvested from bone marrow. This treatment can potentially cure many diseases, especially blood cancers.
Unfortunately, many patients who require SCT do not have these BSCs. These BSCs are usually obtained from a matched sibling. However, many patients are from single child families (hence, no possible sibling donor) or all siblings do not match in some cases. As a result, many of these patients die.
HLA is Human Leukocyte Antigen and refers to the protein structures on white cells. These proteins are responsible for rejecting or accepting foreign cells. HLA is determined by the genes of both parents. Hence parents and child will only be half matched and the best chance of a match will usually be from one of the siblings. The larger the family size, the better chance of finding a match.
The success of SCT depends on HLA-matching. Graft rejection may occur from a HLA mismatch. Fortunately, BSC from cord blood is slightly different and can tolerate some mismatching.
The importance of having HLA-matched BSC has led to the development of the Bone Marrow Donor Registries from unrelated, voluntary donors in the 1980s. They help desperate patients find HLA-matched donors necessary for life-saving stem cell transplants. The first such registry was the Anthony Nolan Registry in the United Kingdom. It was set up by the parents of Anthony Nolan, who died of leukemia because he could not find a matched donor.
Private cord blood banks started in the mid-1990s as knowledge of the usefulness of BSC became widespread. Individuals who appreciated the value of BSC wanted to store these BSC from their child’s cord blood for their own use. This is especially relevant for families who are planning to have one child or a small family size, late pregnancies, and those from mixed marriages. In these families, it may be difficult to find a HLA-matched donor.
Indeed, using your own BSC for SCT may be preferred for some diseases while in other diseases, such as
leukemia, it is better to use a matched sibling’s BSC.
The first umbilical cord blood transplant was performed in 1989 after cord blood was shown to contain large amounts of BSC. Following this success, public cord blood banks developed across America and Europe and currently, the Singapore Cord Blood Bank has been established here.
Cord blood was harvested from voluntary pregnant ladies at delivery. The BSCs were then extracted, frozen and stored. Patients who required a SCT but do not have a donor can then search these cord blood banks for a HLA-matched donor. However, as BSC from cord blood can tolerate some mismatches, it will be easier to find a “usable” donor in public cord blood banks.
Both banks have their own roles. The public cord blood bank plays an important role for patients in Singapore and other countries to draw upon.
Individual families may wish to consider private cord blood banks for their own personal needs. Discuss with the co-ordinators from both banks to enable you to make an informed decision.
Regenerative therapy refers to the use of stem cells to produce new cells for treatment of diseased organs. Examples include the use of stem cells for treating
heart failure, stroke, Parkinson’s Disease, Alzheimer’s Disease and spinal cord injuries. However, most of these are still on an experimental basis, but the initial results are very promising!
Source: Dr TAN Thiam Chye, Dr TAN Kim Teng, Dr TAN Heng Hao, Dr TEE Chee Seng John, The New Art and Science of Pregnancy and Childbirth, World Scientific 2008.
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This article was last reviewed on
Monday, July 5, 2021
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