Stem cell research seems to generate as much controversy as it does promise. These important cells, found in bone marrow and umbilical cord blood, have the unique ability to transform themselves into other cells. They are often used to treat devastating diseases, including leukemia, lymphoma, immune system disorders, and anemia. But what, exactly are stem cells? And why would you even consider storing them?
What Are Stem Cells?
Stem cells are basically beginner cells. No other cell in your body has the stem cells’ unique ability to mature into whatever type of cell your body needs. For example, if the body needs erythrocytes (red blood cells) to help carry oxygen to your body, your stem cells can mature into red blood cells. If your body needs leukocytes (white blood cells) to fight an infection, stem cells can develop into white blood cells. And if your body needs platelets (to help your blood clot), stem cells can develop into platelets.
For the past 30 years, medical technology has allowed us to collect stem cells from the
and use them to help treat certain types of disease, For example, they are often used to rejuvenate the immune system after
. More recently, scientists have found these same stem cells in the umbilical cord and placenta after birth.
These are "fetal" stem cells which "match" the newborn baby, and not the mother.
Cord blood collection begins after a baby is delivered and the umbilical cord is clamped. In a simple procedure, the umbilical cord and placenta are drained, typically resulting in three to five ounces of blood rich in stem cells. The stem cells are then removed from the blood and frozen in a cord blood bank.
There are two types of cord blood banks:
Private storage or banking is a bank where you would pay to store the blood in case a family member should ever need a stem cell transplant in the future. This is sometimes referred to as “biological insurance.” However, private storage fees are expensive—generally including a one-time processing and enrollment fee plus a yearly storage fee. The one-time fee is often in the range of $2,000.
Philanthropic banks are banks where your baby’s cord blood can be donated and stored for anyone who needs it. These banks list their stored samples on the National Marrow Donor Program (NMDP) registry, where doctors can look for a stem cell match for their patients. Generally an expectant mother interested in donation should contact the bank before the 34th week of pregnancy. Many hospitals have a program for their patients. The National Marrow Donor Program has a list of public cord blood banks on their
. Once the blood is donated, families will not be able to retrieve their specific blood later.
Advantages of Cord Blood Transplants
Compared to bone marrow transplants, cord blood transplantation is still in its infancy. Yet the experience so far has been promising. One of the most serious complications that can occur after a bone marrow transplant is graft vs. host disease (GVHD), in which the body rejects the transplant and attacks itself. Cord blood recipients experience GVHD less frequently than bone marrow recipients. The reason for this may be because the majority of cord blood recipients are children who experience less GVHD in general.
Another advantage of cord blood transplants is that a perfect match is not necessary. When matching a donor to a recipient, doctors look at six surface antigens (human leukocyte antigens or HLA). Cord transplants can be done with only four of the six HLAs matching while a bone marrow transplant requires at least five of the six to match.
It is important to note that there are a few unknowns when it comes to cord blood transplants. There are fewer stem cells in cord blood than in bone marrow, and most recipients so far have weighed less than 110 pounds. Whether cord blood can support transplantation in a larger adult is still not known. The long-term prognosis or risk of relapse is also uncertain with cord blood transplants. According to the NMDP, cord blood storage has been effective up to ten years but studies are ongoing to determine overall storage life.
The American Academy of Pediatrics (AAP) estimates the probability of an individual needing to use their own stored cells as somewhere between 1:1000 and 1:200,000. They go on to say that while cord blood transplantation looks promising, it is still “investigational” and they encourage donation versus private storage. According to the AAP, private banking should only be considered in cases where there is a family member who needs or may need a stem cell transplant, or for certain conditions like leukemia and severe hemoglobinopathy (a blood disorder, such as
that is caused by a change in the molecular structure of hemoglobin).
Another way of thinking about this is related to risk. If, at the time of a birth, there is knowledge of a likely need by a family member, then private storage and directed use may make sense. But for the vast majority of couples having a baby, the odds of a family member ever needing a stem cell transplant are in the range of 1:20,000. And, in the unlikely event that someone needs a stem cell transplant, by building large philanthropic banks, that person will be able to have a match.
Since the first successful cord blood transplant in 1988, performed on a child with Fanconi's anemia, over 3,600 patients have been treated with this procedure, including more than 15 who used their own blood cells.
The best solution for a society of people is a number of philanthropic banks, storing as many collections as possible.
Advocates of private banking point to studies that show that patients who receive sibling or related cord blood have a higher rate of survival than those receiving unrelated donor blood. Another advantage is its ready availability as compared to the time needed to find a match—an especially important factor with life-threatening diseases. . Even a sibling donor has a 25% chance of being unsuitable for the recipient, with a 50% chance of a partial match, and a 25% chance of a perfect match.
Weighing the Benefits
Stem cell transplants are currently used to treat over 70 diseases with many more under investigation. Trying to predict the future is not an easy task, and the decision whether to bank or donate your baby’s cord blood is an individual one. In the end, the potential for stem cell technology must be carefully weighed against the potential transplant need—not a simple equation.
Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a