Stem cell transplantation has become an exceedingly hot topic of research in modern medicine. Ever since the first successful isolation of stem cell from umbilical cord blood, banking cord blood is becoming increasingly popular in many countries around the world. The issue of whether to bank or not to bank has also been hotly debated. According to many private cord blood banks, cord blood is a form of “insurance” if your newborn child ever gets sick in the future, and that it's a once-in-a-lifetime opportunity you should take advantage of. I have to admit, it sounds very compelling, so much so that it will make you feel slightly guilty if you chose not to bank the blood. Like most parents, I was faced with the same dilemma of whether to bank the cord blood. After tons of research, I eventually decided not to bank. The reason behind my decision? Let me explain in the rest of this article.
【Stem cell transplantation in brief】
Stem cells are a class of cells in our body that are able to differentiate into many other different cell types. They have this remarkable potential to develop into tissue- or organ-specific cells when given the necessary stimulation. Theoretically, they can be used to repair damaged tissues or organs, and cure many life-threatening diseases. Clinically, stem cell transplantation has been used to cure many hematologic and immunologic disorders such as leukemia, multiple myeloma, and aplastic anemia. The type of stem cell used to cure these diseases are called hematopoietic stem cell or HSCs.
The main source of HSCs is the bone marrow, and this source can be further divided into two: autologous (coming from yourself) or allogeneic (coming from your siblings, twin, or an unrelated stranger). If autologous stem cells are not available or cannot be used, then only allogeneic stem cells can be used. Before an allogeneic source can be used for transplant, it must first go through a genetic test called HLA matching to test its compatibility with the recipient’s cell. The closer the match, the higher chance of successful transplantation, and minimal risk of transplant rejection as well as the potentially fatal graft-vs-host-diseases. Unfortunately, there is only a 25% chance for identifying a perfect HLA match in a sibling donor, and an even lower probability (~ 0.001%) for identifying a matched unrelated donor.
【HSCs in cord blood】
Umbilical cord blood also contains a rich source of HSCs and can be used as an alternative donor source to treat diseases. Unlike bone marrow, it is relatively easier to obtain a good allogeneic cord blood donor source because you don’t always need a perfect HLA-match in order for the transplant to work, a “close enough” match is all you need. Studies have shown that when compared with similarly mismatched bone marrow HSCs, the cord blood is transplantable with a lower risk of graft-versus-host disease. Therefore, cord blood transplant therapy has a greater advantage clinical applications.
【Things that private banks didn’t tell you】
Umbilical cord blood, once considered a human waste, has become a valuable resource after the discovery of stem cell transplantation. Many private banks encourages parents to bank their newborn’s cord blood as a type of “biological insurance” for their beloved child. They will tell you that the cord blood can be used to cure more than 50 diseases, and that it has the potential to cure organ diseases like heart or liver failure if ever there was complications in the near future. You will not have to worry about transplant rejection at all because it is coming from your child’s own body. These claims make cord blood sounds like a magical elixir that cures almost everything, but can we really trust their claims?
There are some things that private bank didn’t tell you:
- The use of cord blood is exaggerated.
Private banks advertise that cord blood is able to cure organ diseases such heart and liver failure. However, there are no data to support the claim that cord blood can be a tissue source for regenerative medical purposes. Therefore, the use of cord blood in novel treatments are, at this point, merely assumptions. Though it is possible in the future, but we are still uncertain about when it will come true. There also is no successful case of using autologous cord blood transplant for the treatment of Malignant neoplasms. Many private banks, however, still made these unverified claims that malignant can be treated with autologous cord blood. So beware of the advertisement private banks made because a lot of the times they are exaggerating the actual usefulness of cord blood.
- Autologous transplantation does not work for congenital disease.
Some diseases can be congenital, means that the child is born with the disease. Examples are leukemia. In some rare cases the fetus will develop acute leukemia even before she is born. This kind of leukemia are caused by natural gene abnormality. As a result, it is highly possible that the cord blood HSCs of the infant also contains the same genetic defect and therefore cannot be used as a autologous source. Abnormal cells have also been detected in the cord blood of children who were not diagnosed with acute leukemia until later in life. Thus, the strategy for children receiving their own cord blood for the treatment of leukemia might even be contraindicated.
- The usability of one’s own cord blood sample is unknown
Typically, the amount of cord blood obtained from a newborn is about 40 to 100 mL. The amount of effective stem cells that can be extracted from a specific sample is even smaller, only enough for the transplant for a small children. In order for a transplant to be successful, the cell dose per weight of recipient is very important. The heavier the weight, the more stem cells you need. Most hematologic diseases won’t show until the child grows older or enters adulthood. At that time, the number of stem cells needed for transplant will be far greater than a single cord blood sample could provide. Cord blood banking is also a relatively new technology. We are uncertain whether or not the freeze-stored cells will remain its viability after decades of storage. This means the “life insurance” has an expiry that is not as long as the advertised 25 years. You might be spending a huge money on the storage for years but only to find out that it is not usable at all. As technology constantly improves, ex vivo cell expansion techniques (which means multiplication of cells outside of a body) may be able to solve this problem. However, at this point, this is only a distant vision.
- The chance of using your own umbilical cord blood is small
Statistically, the odds that privately banked cord blood will ever be used is very small. It might be a good idea to bank the newborn cord blood privately if a full sibling has already been diagnosed with a medical condition that could potentially benefit from cord blood transplantation. However, parents should keep in mind that, even for siblings, the chance of a good HLA-match is only 25% and the blood sample may not even be enough if the sick sibling is a lot older. Therefore, I do not recommend private cord blood banking for healthy families with no history of genetic disorders. If you are thinking about banking cord blood privately, consult a professional first before making the final decision.
- The collection, transportation, and storage of cord blood samples are very delicate procedures.
To ensure the sterility and viability cord blood stem cells, complex procedures must be followed from sample collection to storage. In order to do so, highly trained professionals and hardware that meet set standards are required. If you decide to bank umbilical cord blood, be sure to verify the qualification, make sure their labs, storage environment, and procedures all meet standards before committing to sign a contract.
【It makes more sense to donate】
Base on the current development of biomedical science, AAP discourage saving umbilical cord blood as a “life insurance”, because there are no scientific data as of now to support the use of autologous cord blood transplant. Though theoretically possible, we are uncertain whether the theory will become practice at all, or when exactly will this technology be adopted. Most private banks prey on the parent’s fear of the unknown future, knowing how vulnerable the parents are to the emotional effects of the marketing of cord blood banking. They advertise the many possibility as a reality despite there being a lot of uncertainties still.
Contrarily, there are many successful cases of allogeneic cord blood transplantation. In such cases, the stem cells transplanted are from other individuals. Majority of these stem cell transplants have been done using samples from public banks because a perfect match is not required for cord blood transplantation. This also shows why public donations of cord blood are so important. Donating cord blood increases the amount of samples available for people who are actually in need of it. Although the chance of matching pair between strangers are low, given a large enough sample to choose from, the chance of finding a good sample can still be promising. Donating cord blood maximizes the chance for a patient to find a good matched sample, avoid the life-saving cells going to waste. In addition, by donating the cord blood publicly, we are providing scientists with more research resources.
Due to small possibility of being used and limitation of autologous usage, cord bloods saved in private banks are mostly wasted. On the other hand, donating cord blood makes it available for free to anyone who needs it. Though I do recommend donating over private banking, the decision is totally up to you. Banking cord blood definitely has its value. You can choose to bank the cord blood privately as a biological insurance for future cell therapy if you are comfortable with the cost, but you shouldn’t feel guilty, irresponsible or even ashamed if you decided not to do so. The key is for parents to be given the accurate information by doctors as well as cord blood banks, so they can make rational choice rather than being pushed into making a decision by false advertisement.
American Academy of Pediatrics Section on Hematology/Oncology. (2007). Cord blood banking for potential future transplantation. Pediatrics, 119(1), 165.
Kurtzberg, J., Cairo, M. S., Fraser, J. K., Baxter‐Lowe, L., Cohen, G., Carter, S. L., & Kernan, N. A. (2005). Results of the cord blood transplantation (COBLT) study unrelated donor banking program. Transfusion, 45(6), 842-855.
Sullivan, M. J. (2008). Banking on cord blood stem cells. Nature Reviews Cancer, 8(7), 555-563.