../../cms/~chanatt/125187896804273/visual-09.jpg

About Value of Cord Blood

1. What makes cord blood unique?

2. What are stem cells and why are they valuable?

3. What is the history of cord blood transplantation?

4. How much cord blood is needed for transplants?

5. I’ve heard that they may be able to use cord blood to treat heart disease, spinal injuries and other disorders. Is that true?

6. What is the future of cord blood?




1. What makes cord blood unique?
Cord blood is a rich source of the rare, but precious, hematopoietic stem and progenitor cell that allow for re-population of the blood system to replace diseased and damaged cells. These cells are normally found only in bone marrow and are the essential element in successful bone marrow transplants. Hence, cord blood can be used to treat any cancer that is currently treated by bone marrow transplants.




2. What are stem cells and why are they valuable?
Stem cells are the building blocks of our blood and immune system. They are the production units that produce all other blood cells in the human body (red blood cells which carry oxygen throughout the body, white blood cells which fight infections, and platelets, that are necessary for blood clotting). Stem cells reproduce themselves throughout our lives and are normally found in our bone marrow and even, to a much lesser extent, in our circulating blood. Bone marrow transplants can be lifesaving for people with leukemia (cancer of the white blood cells) and other cancers, or for those with serious blood disorders, such as aplastic anemia (the body does not produce enough blood cells). Stem cells can help enhance a person’s blood-producing and immune systems that have been severely damaged or deliberately destroyed by the high dosage of radiation or chemotherapy that are often used to treat cancers. At present, donated bone marrow is the most common source of stem cells.




3. What is the history of cord blood transplantation?
The first documented and successful cord blood transplantation was performed in October 1988 for a patient with Fanconi anemia[1]. The cord blood collection was made in the United States, and the cells were delivered to Paris for the transplantation. To this date, the patient is alive, well, and completely cured of the disease. Since the first cord blood transplantation, over a thousand cases have been reported worldwide[2]. 




4. How much cord blood is needed for transplants?
It is not the amount of cord blood collected, but rather the number of stem cells contained within the cord blood that matters. Again, the cell count needed for transplant is directly proportional to the weight of the patient. There are other factors that may alter the results of transplants to conclude a fixed quantitative formula for the number of stem cells required. According to medical studies, it was not recommended to transplant a patient with units containing, before thawing, less than 1.5 x 107 NC/kg (NC = nucleated cells)[3]. With advancing technology, alternative procedures or methods for transplant will emerge to lower the number of cell that required.




5. I’ve heard that they may be able to use cord blood to treat heart disease, spinal injuries and other disorders. Is that true?
It remains to be seen if new technology derived from stem cell transplantation will lead to the treatment of disorders such as multiple sclerosis (MS) and Parkinson’s disease as well as spinal cord injuries. So far, these efforts have primarily been limited to the research laboratory and have not produced benefits in patients. Conceptually, stem cells needed to treat disorders such as MS, Parkinson’s and injuries responding to regenerative treatment such as heart attacks can be derived from the cord blood.




6. What is the future of cord blood?
Cord blood stem cells offer some exciting possibilities for gene therapy for certain genetic diseases, especially those involving the immune system.

In 1993, Dr, Donald Kohn, M.D., and colleagues at the Children’s Hospital of the University of Southern California in Los Angeles and the University of California in San Francisco, made the first attempt at gene therapy with cord blood in three children suffering from adenosine deaminase (ADA) deficiency, a potentially fatal defect that cripples the immune system.(4) The children, who also received polyethylene glycol-conjugated ADA (PEG-ADA) enzyme replacement therapy, appear healthy to date, even though their blood now carries only a small amount of the gene introduced by stem cell transplantation. However, cessation of the PEG-ADA enzyme replacement in one subject led to a decline in immune function, despite the persistence of gene-containing T lymphocytes. Thus, improved gene transfer and expression will be needed to attain a therapeutic effect.

Given that one of the limiting factors in cord blood is the limited supply of the sample, exvivo expansion of cord blood stem and progenitor cells research and studies are underway.  Successful results will compensate for the amount of cells present in each sample. There are recent breakthroughs on this issue by a U.S. firm, Aastrom Biosciences, Inc. in connection with Hackensack University Medical Center where they successfully transplanted cord blood that was produced ex-vivo.

We are the private sponsor of a project conducted by the Chinese University of Hong Kong on the same issue. We hope the project will generate some positive results to resolve the issue of insufficient cell count of the samples collected.


Footnotes:
[1] Broxmeyer HE. Cellular Characteristics of Cord Blood and Cord Blood Transplantation. AABB Press 1998;1-4.
[2] Gluckman E, Rocha V, Chastang C. Ham-Wasserman Lecture - Cord Blood Hematopoietic Stem Cells Biology and Transplantation. Hematology 1998 American Society of Hematology Education Program Book 1998;2.
[3] Gluckman E, Rocha V, Chastang C. Ham-Wasserman Lecture - Cord Blood Hematopoietic Stem Cells Biology and Transplantation. Hematology 1998 American Society of Hematology Education Program Book 1998;10.
[4] Broxmeyer HE, Srour EF, Hangoc G, et al., High-efficiency recovery of functional hematopoietic progenitor and stem cells fomr human cord blood cryopreserved for 15 years. Proc Natl Acad Sci USA 2003;100:645-50.