Lifeline Business Profile
September 25, 2017
Umbilical cord blood banking has become increasingly popular in recent years, with a number of businesses both public and private offering the service. It’s a relatively new concept, and there’s uncertainty about its overall value and whether it’s worth considering for a newborn child. We discuss the technology, its implementation, and how and why people are opting to store this blood for years — or decades.
Cord blood banking is the act of cryopreserving blood from a newborn baby’s umbilical cord. The idea is that if newborn Jane has some cord blood banked on her behalf by her prudent parents, and then Jane herself ends up needing certain stem cell therapies later in life, she won’t have to go hunting for a donor. Stem cells will be waiting there for use in a transplant or graft.
How Cord Blood Banking Works
The use of placental and cord blood stem cells doesn’t have the same attendant controversy as the use of embryonic stem cells. Right after a newborn baby takes its first breath and the umbilicus is cut, about 75-100 mL of blood is drained from the cord/placenta. That’s where the blood comes from–they never have to touch the baby with a needle.
From there, the task is careful cryopreservation of the cord blood sample. This is where it gets tricky. After a few decades of working with tissue samples and IVF embryos, we’ve figured out a whole lot we didn’t know about how freezing affects tissue–and how to mitigate the risks posed by freezing damage.
When you think about freezing from the perspective of chemistry, on the fine scale, things start to look very different below 0° C. Freezing turns liquid water into crystalline ice, which pulls liquid water molecules out of solution. This raises the effective concentration of whatever is dissolved in the liquid phase, and you can’t just go raising osmotic concentrations in tissues to whatever arbitrary level. That’s not great for cells. Worse, as it forms ice makes needle-like crystals that can puncture and destroy cells. This is part of the reason frostbite is so damaging; it destroys the tissue that freezes.
To overcome these significant problems, scientists developed a technique called slow freezing. Slow freezing is intended to give water molecules time to move osmotically across cell membranes, so ice crystals don’t form inside cells. It’s like freeze-drying, but not quite so drastic. This is the technique we already use to preserve embryos for IVF, and it’s also a technique we now use to preserve cord blood.
Biological processes don’t just stop when water freezes. While the reaction times do slow down, proteins work like tiny ratchets driven by Brownian motion. Even when it’s cold, they still march through their reactions. As a consequence, cord blood samples have to be stored at very cold temperatures. But even in liquid-nitrogen-cooled cryostorage, the National Marrow Donor Program says the cord blood may only be viable for 10 years or so.
Is the Service Useful?
Umbilical cord blood and blood from the placenta both contain hematopoietic progenitor cells (HPCs)–the stem cells that produce blood cells. The same kind of cells are found in adults’ bone marrow, where it maintains our population of blood cells. Stem cells from cord blood can treat a heavy handful of medical problems, mostly in children: sickle cell anemia, leukemia, and other diseases that impact the immune system or blood cell production all have treatments that involve HPCs. Diseases or treatments that destroy bone marrow can also require donor cells to replace the destroyed tissue.
Skeptical doctors and experts tend to refer to cord blood banking as an “expensive insurance policy” against future genetic disease. While it certainly doesn’t incur any risk to bank a little blood, the upfront and per-month cost of storage is significant. It’s not certain that the banked cord blood will be viable. And if calamity befalls, one’s own banked HPCs may not be useful to treat the disease at hand. Stem cells aren’t necessarily a magic biotechnological bullet, even if they’re your own.
But for the diseases that can be treated by HPCs, it’s better to have stem cells available than not to have them. Families with a genetic history of sickle cell anemia, leukemia, or other blood disorders may wish to discuss this option. The utility of cord blood is in its stem cell content. Because stem cells haven’t really been “trained” yet, they don’t provoke the same magnitude of immune response as other, more mature cells. This means that the risk of graft versus host can be partially mitigated, or even eliminated completely with an autologous stem cell graft.
Parents can choose to store their newborn’s cord blood in a private bank for their own later retrieval or donation, or they can choose to donate their newborn’s cord blood to a public bank, where any donor who matches can retrieve it. Because of the relatively smaller likelihood that stem cells will provoke an immune response in a donor, these donations are of particular benefit to ethnic minorities, who may find it more difficult to find matches in the bone marrow donor registry.
Stem cell treatments are still in their relative infancy, and so is gene therapy. But with advancements in both fields, we’ll get better control over what genes a cell is expressing and when. With finely tuned stem cells at our disposal, we can turn them into laser-targeted cancer-destroying therapeutic tools, as well as using them to make effective tissue grafts and transplants.
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