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When an immediate family member has a disease
that requires a stem cell transplant, cord blood from a newborn
baby in the family may be the best option. There is a 25% chance,
for example, that cord blood will be a perfect match for a sibling. A baby's cord blood will automatically share half (3/6) of its HLA antigens with each parent, but occasionally will be a better match for a parent if, by chance, both parents have some of the same HLA antigens. The baby's cord blood is less likely to be a good match for more distant relatives. Inventories of unrelated cord blood units in public cord blood banks may be a better source of appropriate matches for parents and distant relatives, as well as for siblings that do not match.
Private companies offer to store
cord blood for anyone who wants it done, whether or not there is any medical reason known to do so at the time. The fee for private storage varies, but averages about $1,500 up front and $100 per year for storage. When there is no one in the family
who needs a transplant, private storage is for purely speculative purposes, what
some companies have termed "biological insurance."
However, parents should know that a child's own cord blood (stored at birth),
would rarely be suitable for a transplant. It could not be
used at present to treat genetic diseases, for example, because the cord blood stem cells and their descendents would
be affected by the same condition. (See the story of Anthony
Dones.) In addition, most transplant physicians would not use
a child's own cord blood to treat leukemia. There are two reasons
for this reluctance. First, in most cases of childhood leukemia,
cells carrying the leukemic mutation are already present
at birth and can be found in the cord blood. Thus, pre-leukemic cells may be given back with the transplant. Second, in a child
with leukemia, the immune system has already failed to prevent leukemia.
Since cord blood from the same child re-establishes the child's own immune system,
doctors fear it would have a poor anti-leukemia affect.
Some private cord blood banks claim that cord blood, just like bone marrow, can be "purged of cancer." This claim is purely speculative, however. So-called purging can be done by "selecting in" the immature cells (i.e., CD34-positive cells) that include the true stem cells. So far, however, these cells cannot be selected very well when the cord blood has already been frozen. Purging also can be done by "selecting out" the cancer cells. However, there is no evidence that the cells in cord blood that have the leukemic mutation actually express the surface markers or antigens needed to remove them. Thus, purging of cord blood for leukemic or pre-leukemic cells is not proven in fact; and, there is reason to believe, may not be possible.
The odds of finding a suitably-matched,
publicly-donated, unrelated cord blood unit are already quite high and are improving steadily as inventories of public cord blood banks grow.
For these and other reasons, the American Academy
of Pediatrics (AAP) and many physicians do not recommend private cord
blood banking except in cases where a family member already has a current
need or very high potential risk of needing a bone marrow transplant.
In all other cases, the AAP has declared the use of cord blood as
"biological insurance" to be "unwise." [Read the AAP's news release at
http://www.aap.org/advocacy/archives/julcord.htm ]
The European Group on Ethics in Science and New Technologies (EGE) has also adopted a position on the ethical aspects of umbilical cord blood banking. The EGE is of the opinion that "support for public cord blood banks for allogeneic transplantations should be increased and long term functioning should be assured." They further stated that "the legitimacy of commercial cord blood banks for autologous use should be questioned as they sell a service which has presently no real use regarding therapeutic options."
The Medical Letter On Drugs and Therapeutics also recently addressed aspects of public and private cord blood banks, asking the question: "Does Private Banking Make Sense?" After citing various statistics on the actual uses of privately stored cord blood, they concluded that: "At the present time, private storage of umbilical cord blood is unlikely to be worthwhile. Parents should be encouraged to contribute, when they can, to public cord blood banks instead." [Access The Medical Letter at www.medicalletter.org].
Other references pertaining to private cord blood storage vs. public cord blood banking are listed below:
Fernandez CV, Gordon KE, Van den Hof MC, Taweel S, Baylis F. "Attitudes of pregnant women to cord blood stem cell collection, testing and donation". Canadian Medical Association Journal; Mar 18, 2003; 168(6).
Kline RM. "Whose blood is it, anyway?" Scientific American 2001;284(4)-42-9.
Pearson HA, et al. "Cord blood banking for potential future transplantation: subject review." American Academy of Pediatrics. Work Group on Cord Blood Banking. Pediatrics 1999;104;116-8.
Johnson FL. "Placental blood transplantation and autologous banking--caveat emptor." Journal Pediatric Hematology-Oncology 1997.
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