Treating Disease with Stem Cells Essay

This essay has a total of 1073 words and 7 pages.

Treating Disease with Stem Cells



Treating Disease with Stem Cells

This article was written by Dr. Gregory Hale, professor of Pediatrics at the University of
Kentucky College of Medicine, in response to questions posed by Scientific American
Magazine regarding the treatment of certain diseases with cord blood stem cells. There is
some additional information provided by Viacord, a medical service company that provides
private family cord blood banking, processing, and research. Dr. Hale discussed the
advantages of cord blood stem cell transplants, the results of several transplants, as
well as the research that on-going in the field of stem cell transplantation.

The blood that remains in the human umbilical cord blood following birth contains a rich
source of hematopoietic progenitor cells known as “stem cells.” These stem cells are the
master cells of the blood. They divide to make new red cells that supply oxygen, white
blood cells that fight disease and infection, and platelets that facilitate healing.
Doctors now have three sources of stem cells available to them: bone marrow, mobilized
bone marrow or peripheral blood, and umbilical cord blood. Bone marrow has traditionally
been used as a source of stem cells, but research is proving that cord blood may be an
excellent alternative source. Cord blood can be utilized for the treatment of many
diseases, including leukemia, sickle cell anemia, and Hodgkin’s disease. The first
successful cord blood transplant took place in 1988 when a newborn’s cord blood was used
in a life saving stem cell transplant for her older brother who had Fanconi anemia.

Since then, there has been much research into the advantages of cord blood stem cells.
Cord blood is much more readily available and poses no donor risk. The blood is simply
collected from the placenta and umbilical cord after the baby is born and stored. The
potential of expanding the ethnic diversity of the donor pool is greatly increased, since
minorities are considerably under-represented in bone marrow transplant pools. Cord blood
stem cells may also pose less risk of graft-versus-host disorder, or GVHD, than stem cells
from bone marrow. GVHD occurs when the donor’s immune cells make antibodies against the
host’s tissues, resulting in serious complications.

In the last ten years, several studies of cord blood transplants have taken place and
their results have been published in science and medical journals. In 1996, the New
England Journal of Medicine reported the results of 25 consecutive cord blood
transplantations from August 1993 to November 1995 by Dr. Joanne Kurtzberg at Duke
University. After bone marrow searches were unsuccessful for 17 patients, cord blood was
collected from unrelated donors at the New York Blood Center. Nineteen patients had
malignant diseases and four had nonmalignant conditions. The patients’ average age was
seven years and the average weight was 19.4 kilograms. Twenty cord blood units were
slightly HLA-mismatched and one was HLA-identical. The HLA, or Human Leukocyte Antigen,
induces the formation of antibodies because it is recognized by the immune system as a
threat. Engraftment was successful in 23 of 25 patients, and only two patients had severe
graft-versus-host disease. In contrast, bone marrow transplants in children have a 30
percent incidence of graft-versus-host-disease. Seven of the patients with malignant
disease and 6 with nonmalignant conditions were alive one year after transplantation. The
report concluded that “HLA-mismatched cord blood is an alternative source of stem cells
for transplantation in children.”

In another study by Dr. John Wagner at the University of Minnesota Hospital, 13 patients
with malignant leukemia diseases and five with nonmalignant conditions received cord blood
transplants between July 1994 and December 1995. The average age of these patients was
2.7 years and the average weight was 15.4 kilograms. Seven patients received HLA-matched
blood and 11 received varying degrees of HLA-mismatched grafts. Six months after
transplantation, 65 percent of the patients were alive and only two developed severe
graft-versus-host disease. The authors stated that the benefits of cord blood
transplantation included the “low rate of graft-versus-host disease, rapid availability of
blood, lessened donor risk, and a low risk of transmissible infections such as
cytomegalovirus and Epstein Barr virus.”

Even with these and other successful transplantations, there are still questions to be
answered. For example, what is the minimal cell dose? Can an adult recipient be
effectively transplanted? Because the volume of umbilical blood collected at birth is
between 80 and 100 milliliters, the majority of transplants have been pediatric cases.
Continues for 4 more pages >>