Media Centre
Fact sheets: Umbilical cord blood stem cells background information
Stem Cells
Stem cells are cells which can develop into
- All other types of cells and tissue
- New cells with specific functions
- Cells that are an exact copy of the stem cell itself
- Or a combination of the above
Stem cells can be found in the body at all stages of life - from the very early embryo right through to old age. They are found in a range of locations including in bone marrow, peripheral blood, cord blood, the skin, the liver and the retina. Through the course of a person’s life the type and location of these stem cells change.
Types of Stem Cells
Stem cells are one of two types - adult stem cells or embryonic stem cells. Virgin Health Bank is only involved in the collection and storage of adult stem cells from umbilical cord blood. Details on adult stem cells are given below, with a brief summary of embryonic stem cells following.
Adult Stem Cells
Adult stem cells are sourced from various tissues including bone marrow, peripheral blood and umbilical cord blood. They can be pluripotent (could develop into any other type of cell, dependent on the source of the stem cell), multipotent (could develop into a range of other cells) or unipotent (could develop into only one type of cell).
Adult stem cells are available for use in treatments through collections from healthy donors – such as bone marrow registries or cord blood banks.
Adult stem cells – current uses
Bone marrow , peripheral blood and cord blood stem cells are routinely used in transplantation for blood disorders today for blood disorders such as leukaemia.
The cells are injected or infused into the patient, where they move through the blood stream and gradually settle in the bone marrow (a process called engraftment) where they grow, and replace the diseased cells.
Since 1988, more than 7,000 cord blood transplants have been performed in more than 150 locations around the world. The vast majority of these have been allogeneic transplants (the stem cells are from another person and tissue matched to the patient).
In Japan, 50% of stem cell transplants between unrelated individuals now use cord blood.
A systematic review in American Society of Haematology demonstrates survival rates after cord blood transplantation of up to 77% after two years.
There are more than 24,000 cases of leukaemia in the UK per year. 50% of patients put forward for a bone marrow transplant in the UK are unable to find a matched donor.
Umbilical Cord Blood Adult Stem Cells – the future
Cell Expansion
Currently, a typical 20-25ml unit of cord blood contains enough adult stem cells to achieve an effective graft in a patient up to 45kg. For larger patients, suitably matching cells from more than one donor can be combined. It is therefore important to have as large a bank available as possible in order to increase the chances of finding a match.
There is evidence for the successful expansion of stem cells in the laboratory. Ultimately, cell expansion will mean that larger patients, and more patients, will be able to be treated from a single sample. Research in cell expansion technology is progressing and the first patented processes are expected by 2010.
Regenerative Medicine
Autologous cord blood stem cell transplants are currently used very infrequently and where they have occurred they have been for exclusively haematological applications.
The future promise of regenerative medicine is much broader than this and relies on the presence in cord blood of stem cells such as mesenchymal stem cells. The long term goal is to grow replacement tissues in the body as it may be advantageous for a patient to have a supply of their own stem cells that are genetically identical to every other cell in their body, to help prevent graft rejection after transplant.
Research is being undertaken worldwide looking at other diseases that could be treated with UCBSCs in the future. Until this research is complete, it is impossible to say with certainty which diseases will respond best to stem cell therapies, however there have been promising early results in studies investigating heart disease, Parkinson’s disease, spinal cord injury, stroke, osteoporosis, skin burns, osteoarthritis, tendon, muscle and ligament injuries.