Could the blood from an infant’s umbilical cord hold the potential to help save another person’s life?
It was a question put to the test in 1988 when the first-ever cord blood transplant occurred. A young boy with a rare blood disorder received stem cells from his newborn baby sister’s umbilical cord blood, and the transplant was successful in improving the boy’s health.
In the decades since, thousands of cord blood transplants have occurred, scientists have continued to research the potential uses of cord blood, and July has become National Cord Blood Awareness Month. However, cord blood does have limitations and there are some private companies that appear to be promising it can do things it cannot, warns hematologist Jonathan Gutman, MD, co-medical director of the University of Colorado Cord Blood Bank, a professor of hematology in the CU Department of Medicine, and director of cell therapies and the stem cell transplant program at CU.
“Cord blood has a lot of intriguing characteristics that we might be able to use for clinical benefit, and it has historically served an important role as a donor source for patients, particularly patients from racial and ethnic minority groups,” Gutman says. “But it’s not a magical panacea, and it is not in a place where it can be used to cure a lot of the things that some companies are suggesting.”
Cord blood has a number of properties that make it appealing as a therapeutic tool for patients, Gutman explains.
“It is very rich in blood-forming stem cells, and so it’s been used for years as a donor source for stem cell transplants,” Gutman says. “There are also other cells in cord blood that have different immunologic properties. These young, healthy cells have characteristics that are different from adult cells, and they can potentially be used for other therapeutic benefits.”
As a CU Cancer Center member who specializes in stem cell transplants for patients with leukemia and other blood cancers, Gutman helps care for some of the “most complicated, most sick patients,” he says. Patients typically need stem cell transplants when their bone marrow or blood cells have become diseased in order to start producing healthy blood cells again.
“To do a stem cell transplant, the donor has to appropriately match a critical set of the recipient’s genes for how their immune system functions,” Gutman says.
If a patient does not have a relative who is a donor match, then an alternative is to search for a potential match through the National Marrow Donor Program.
“There is a pool of about 40 million people who said they might be willing to be donors. We can look at that pool and see if you have a match — but your odds depend quite a bit on your race and ethnicity,” he says.
Caucasian people have a roughly 70% chance of finding a match in that pool, he explains, whereas a person of color may only have a roughly 10% chance of finding a match. For these patients who have no matches, cord blood can be a valuable resource.
“Because of its unique immunologic properties, cord blood doesn't need to be as closely matched to the donor. For patients who lack other options, we would often have cord blood as a potential donor source for transplant,” he says. “In our program, historically, we’ve been big advocates for the use of cord blood.”
There was a lot of enthusiasm surrounding the potential of cord blood and the need for cord blood banks around the 2010s, Gutman explains, but in the recent decade, its popularity and use appears to be on the decline.
“The problem with the cord blood banking industry is that there is no sound financial model,” he says. “You have a big inventory of cord blood units and have to pay a lot to store and test them, but very few of the units are used.”
According to research published in 2021, over 778,000 cord blood units had been stored across the globe but only approximately 35,000 umbilical cord blood transplantations had been performed as of 2019. Gutman explains that one of the biggest issues is the size of the stored units.
“A cord blood unit often has 10 times fewer cells than we would typically get from a donor if we were going to do a transplant,” he says. “It turns out that probably about 80% to 90% of cord blood units are just not big enough to be used.”
Many cord blood banks have stopped collecting new cord blood units, including the blood bank at CU. A main reason why is because there are promising alternatives, Gutman explains. One of those alternatives is referred to as haploidentical or half-matched donors.
“Any child, parent, 50% of siblings, and 25% of first cousins will be half-matched to a patient. With the innovations and improvements that we’ve made in half-match donor transplants, that has become a viable strategy — and it can be easier to deal with than cord blood,” he says.
“Cord blood is often more expensive, and the early transplant period is often more complex, which has steered some people away from it,” he adds. “Although it is on the decline, we still believe it has its place in stem cell transplants for patients who don’t have other options.”
Beyond stem cell transplants, some scientists are also investigating if cord blood could be useful for regenerative medicine.
“There are researchers who are using cord blood cells as the starting point to grow new cells and cell therapies,” he says. “There’s the possibility that some of the unique immunologic features of cord blood might give it advantages over adult cells, so there are projects looking at how these other immunologic cells in cord blood might be used for treating autoimmune diseases.”
Historically speaking, there have been two places where cord blood is stored. The first is a public banking system, like CU’s cord blood bank, where the units are stored and later used to help a patient getting a stem cell transplant. The other is a private banking industry, where companies will offer to store a person’s cord blood for a price.
Gutman warns people that these private companies may use somewhat manipulative messaging to advertise the benefits of cord blood, sometimes over-promising what cord blood can do as a way to convince people that they should store their cord blood.
“Some companies will solicit pregnant women about whether they want to store their cord blood for a fee. They will say that storing cord blood will be beneficial in case a person gets cancer, needs a transplant, or faces other medical issues. Sometimes they hint that cord blood might be able to one day help a person grow a kidney or a liver,” Gutman says. “At this point, that is not the reality. By selling this idea, it makes it unclear and murky what cord blood can actually do.
“Also, there are not rigorous regulations associated with these private banks, so you might store the cord blood and it may not be good when you go to get it,” he adds. “It’s important to be aware that cord blood may not be as valuable as these companies portray.”