What Is Cord Blood And What Is Cord Blood Stem Cells Used For?
What Is Cord Blood?
Cord blood (umbilical cord blood) is the blood that remains in the placenta and umbilical cord following childbirth. It is found to be rich in blood stem cells, similar to those found in bone marrow. Research has shown that blood extracted from the umbilical cord can be used used to treat many different cancers, immune deficiencies, and genetic disorders.
What Treatments Is It Used For?
Cord blood was once discarded as waste material before it was discovered to be a useful source of blood stem cells. Stem cells are immature cells that have the potential to develop into different cell types. There are various conditions for which a cord blood stem cell transplant may be used:
- Malignancies (cancers of the blood, e.g. Leukaemia, lymphoma)
- Bone marrow failure (when bone marrow doesn’t produce the cells it should)
- Haemoglobinopathies (blood disorders such as sickle cell anaemia)
- Immunodeficiencies (when the immune system doesn’t work properly)
For some of these treatments, the stem cells are the primary treatment. For others, treatment with stem cells may be used when other treatments have not worked or in experimental research trails.
Advantages and Disadvantages Compared to Bone Marrow
Advantages
There are a number of advantages of using cord blood stem cells compared to using bone marrow samples.
- The stem cells from cord blood can have a greater number of matches when used in blood transplant and are less likely to be rejected by the body compared to bone marrow transplants.
- Collecting bone marrow is an invasive and painful procedure for the donor and has a number of risks.
- Cord blood can be frozen stored longterm via cryopreservation while bone marrow samples need to be used as soon as they are collected.
- The stem cells from cord blood have shown to strengthen the immune system during certain cancer treatments while bone marrow samples have not such capability.
Disadvantages
An unfortunate disadvantage is that a single collected sample does not contain enough stem cells and several donor samples have to be combined to increase the number of stem cells if a transplant is needed for an adult.
The Collection and Storage
Cord blood is the blood left over in the placenta and umbilical cord after childbirth. It is rich in hematopoietic stem cells and is composed of all the elements normally found in whole blood. It contains red blood cells, white blood cells, plasma, and platelets. The most commonly used method in clinical practice for collecting cord blood is called the “closed technique”. The closed technique is a method that is similar to standard blood collection techniques and involves the technician cannulating the vein of the umbilical rod and using a needle connected to a blood bag to collect the flowing blood. On average, about 75 ml of cord blood is collected.
The collected sample is cryopreserved and then stored in a cord blood bank for future transplantation. Cryopreservation is a process where biological matter is preserved by cooling to very low temperatures. The red blood cells are removed from the collected cord blood before cryopreservation to ensure high rates of stem cell recovery. Research has shown that cryopreserved cord blood can be stored for up to 25 years or more and still be used successfully in a stem cell transplant.
What is Cord Blood Banking?
A cord blood bank is a facility that stores the cord blood for future use. In response to the potential use of cord blood in treating diseases, both private and public cord banks have developed.
Public cord blood banks function in the same manner as a public blood bank, accepting donations to be used for anyone in need. While private cord blood banks store cord blood for the sole use of the donor or donor’s family and charge a fee for collection and storage.
Storage and Personal Use
Recently many people have using private cord blood banks to store their babies sample after birth. However, the probability of using one’s own cord blood for the treatment of blood cancers and diseases is extremely low. This is because the genetic defects that cause the illness in the first place are often already present in the patient’s own cord blood, making it useable.
Within a family, a healthy baby’s cord blood could have a 25% chance of being a match for a sibling in need of treatment.
Misconceptions of Cord Blood
Treatment with cord blood is experimental
Cord blood has been stored and used in the treatment of over 80 different blood, immune, and cancer diseases. More than 30,000 successful transplants have been performed since the first transplant performed in 1998.
The collection of the sample can affect the birth and delivery process
This is incorrect as the sample is collected after the birth of the child from the cut umbilical cord. Therefore the process is considered painless, easy, and safe for mother and child. It was once considered as waste material before it was discovered to be a useful source of blood stem cells.
It’s unlikely the child will be able to use their own sample if they get ill
Although this statement is not true the possibility of the need occurring is very low. Any genetic condition that the cord blood could be considered as an option would not be able for the person suffering the condition as the same genetic abnormalities would also be present in their own cord blood sample. However, the stem cells can be used in transplants for certain treatments involving non-genetic dieases and cancers.
Cord Blood Stem Cells vs Embryonic Stem Cells
Stem cell research has sparked ethical, religious, and political debates over the recent years. So what is the difference between the stems cell collected from cord blood and embryonic stem cells? Embryonic stem cell collection involves the destruction of a human embryo while the stem cells collected from cord blood come from the blood left over in the placenta and umbilical cord after childbirth, and causes no harm to the baby in any way.
Current and Future Research
Although there is ongoing research for the potential uses of cord blood stem cells beyond blood and immunological uses, the potential uses are limited due to the fact that cord blood stem cells are hematopoietic stem cells. This is a limitation because hematopoietic stem cells can only differentiate into blood cells, while embryonic stem cells can differentiate into any type of tissue.
A major research is focused on trying to increase the number of hematopoietic stem cells that can be obtained from a single sample. This is because a major limitation of cord blood transplantation is that the obtained sample from a single umbilical cord does not contain as many hematopoietic stem cells as a bone marrow donation.
There have been several reported studies in animal testing suggesting that cord blood can repair tissues other than blood. However, these findings are controversial as the tests are often not reproducible, as there is no clear understanding on how cord blood stem cells have such effects. It’s been suggested that the positive effect caused by the cord blood cannot be explained by the stem cells repairing damage itself but rather that the cells in the cord blood could be releasing a substance that may be helping the body repair damage.
In recent years, there have been a number of trials conducted in the field of regenerative medicine. The clinical trials explore the use of one’s own cord blood for the treatment of cerebral palsy, hypoxic-ischemic encephalopathy, and autism. Although there have been some encouraging results within the early stages of these clinical trials, the efficacy of there experimental treatments still remains unproven.
Placental tissue, amniotic membrane, and cord blood are also being used by drug manufacturers to make new drugs. Biological components from placentas can be found in products made by MiMedx for wound and burn care, while an Israeli company, Gamida cell, has developed a drug containing cord blood stem cells and is currently in phase two clinical trials for the treatment of blood diseases.
The US Food and Drug Administration (FDA) has recently approved the use of stem cell-based therapy derived from the human placenta for emergency treatment of patients exposed to high levels of radiation.
Heart Disease
Cardiovascular diseases are one of the most common causes of death. New research has shown that healthy cord blood stem cells can be used to repair heart tissue and help strengthen a weakened heart. Researchers injected stem cells intravenously into patients area of heart damage stimulating dormant cells to become active, or in some cases transform into new heart muscle cells to repair and reinforce the heart.
The results were published by the American Heart Association revealed an overall improvement in the heart’s ability to pump blood in patients that had suffered in heart failure by using umbilical cord stem cells.
There are many ongoing studies looking into the possible use of cord blood stem cells to help mend congenital heart defects, as well as, other defects that may occur when a baby is developing.
One possibility was published by the researcher at The University of Bristol who are looking into mending congenital defects by using living tissue grafts made from umbilical cord stem cells.
Type 1 Diabetes
This form of diabetes is often diagnosed during childhood. The body’s immune system attacks the insulin-producing cells in the pancreas. A possible solution currently under investigation is the use of cord blood stem cells to help keep the immune system in balance. This is because they contain a much greater number of regulatory T cells which can be used to stabilise the body’s immune response.
Another possibility been researched is preventing the possibility of type 1 diabetes by using the cord blood stem cells to reboot the immune system before the autoimmune response can occur.
Looking Ahead
Although there still might be some ethical issues raised regarding the use of stem cells, stem cell therapy is now a well-accepted treatment method for a wide range of diseases. Going forward, the future looks bright for treatment of disease using umbilical cord blood stem cells as many research institutes are assessing its use and have seen positive results so far.
Researchers are continuing to discover new potential treatments and use cases for stem cell therapy. But we still have a long way to go and more investment is required in the field to move forward with promising clinical trials.
