杏吧原创

IT IS only half a cup of blood, but it could change your life. Blood taken from a newborn baby鈥檚 umbilical cord is a rich source of uniquely potent stem cells. Parents are often encouraged to donate it to a public bank, so that it might be used to treat others with rare blood disorders.

However, there is no guarantee you will get to use your own blood later if you need it. This was not a problem when the disorders it treated were exceptionally rare. But this is changing.

Even now, researchers are busy investigating whether cord blood could be used to treat more common disorders including heart disease, diabetes and Alzheimer鈥檚. Hundreds of trials are under way, and some are starting to show positive results.

Perhaps unsurprisingly, a growing number of people are choosing to bank their children鈥檚 cord blood privately, even before the science is settled. Given that they might not need it for decades, should you hedge your bets and bank your baby鈥檚 cord blood?

The official line 鈥� touted by organisations including the and the American Academy of Pediatrics 鈥� is that private banking should be discouraged, or at least not recommended, because it is a waste of time and money.

鈥淔rankly, I encourage parents to put the money towards college education,鈥� says at Massachusetts General Hospital in Boston.

鈥淩esearchers are busy investigating whether cord blood could treat common disorders like diabetes鈥�

In the UK, you鈥檒l pay between 拢1000 and 拢2000 to bank the blood in the first place, followed by an annual storage fee of around 拢100. Costs are similar in the US, where banking cord blood for 20 years will set you back around $4000. While it is free to donate, there is no guarantee you will get to use the blood later if you need it.

That doesn鈥檛 matter much based on current uptake. Since banking took off in the 2000s, an estimated , but only around 35,000 transplants have been performed. That鈥檚 a take-up rate of less than 5 per cent. A whopping 4 million units are thought to be stored in private banks, though no figures are available on how many of these have been used.

With such a big public supply, private banking seems like an unnecessary expense. As rare disorders are, well, rare, there is only a vanishingly small chance that someone whose parents banked their cord blood will end up using it for such conditions.

However, according to a new wave of research, there could be a lot more to cord blood than just treating rare diseases.

That鈥檚 largely down to its rich supply of stem cells, which have the ability to become many other cell types in the body. A newborn鈥檚 cord blood cells are particularly 鈥渘aive鈥�, meaning they are thought better at morphing into new types than other stem cells.

That makes cord blood useful for treating rare blood cancers and bone marrow disorders. These diseases can wipe out a person鈥檚 blood cells, as can treatment itself, but stem cells can replenish the body鈥檚 blood cell supply.

Reject me not

Adult bone marrow can be used as a source of stem cells, but cord blood cells seem to be more effective. Their naive state makes them more malleable and less likely to be rejected by the body鈥檚 immune system. 鈥淭he advantage is that umbilical cord blood doesn鈥檛 have to be perfectly matched,鈥� says at the University of Virginia.

These benefits have led to an explosion in research 鈥� if the cells can form beating heart tissue, could they cure some cardiovascular diseases? If they could become neurons, might they treat neurodegenerative disorders like Alzheimer鈥檚? The possibilities seem endless.

In 2013, and his colleagues at the Ottawa Hospital Research Institute in Ontario assessed the research into cord blood. The group hunted for the results of published studies in people. 鈥淭here were lots of small reports, with no control groups,鈥� says Allan, meaning no one was given a placebo treatment for comparison. 鈥淚f there鈥檚 no control group, you don鈥檛 know if the treatment is beneficial 鈥� it could be harmful.鈥�

When the team repeated their study this year, they found that research into cord blood had exploded. 鈥淲e found 57 clinical trials that included over 800 patients,鈥� says Allan. Sixteen of these included a control group. Most of the trials were conducted in China and the US (Biology of Blood and Marrow Transplantation, ).

And these are just the published results 鈥� are looking at a range of diseases and disorders and are yet to report their findings.

The most commonly studied is cerebral palsy, a group of disorders caused by abnormal development or damage to the brain that can impair movement. To date, results have been published from four placebo-controlled trials, which included a total of 141 people. All four studies found that an infusion of cord blood seemed to be beneficial, lessening the symptoms of people with cerebral palsy.

Three trials investigated cord blood for treating type 1 diabetes, which tends to start early in life, and is caused by the immune system attacking the body鈥檚 insulin-producing cells. So far, results are mixed, but at the University of Florida is hopeful.

That鈥檚 because cord blood has unusually high levels of a type of immune cell that dampens down the activity of other immune cells. These regulatory T-cells are lacking in people with type 1 diabetes, says Haller, who is running his own clinical trial. 鈥淭here鈥檚 the potential to give them back,鈥� he says.

There are plenty of trials testing cord blood for disorders of the brain and spinal cord, too. Allan鈥檚 team found published results from 25 clinical trials of neurological disorders, including traumatic brain injury, stroke, spinal cord injury and degenerative conditions like multiple sclerosis and motor neuron disease. These are showing positive results: cord blood reduces inflammation and boosts the growth of new neurons and blood vessels.

So it seems cord blood shows promise for future treatments, but Allan is keen to stress that they are still very much preliminary. 鈥淲e can鈥檛 say these are proven treatments,鈥� he says. 鈥淲e need bigger studies and more long-term evidence.鈥�

And if some treatments do work, there are still questions over exactly how the cord blood should be obtained, stored and treated. Some groups inject the stored cord blood as it is, but others are working on ways to isolate the most potent stem cells from the mix. It鈥檚 also unclear if we can rely on cord blood stored longer than 20 years, as normal transfusion blood is not kept this long.

鈥淲e can鈥檛 say these are proven treatments, we need bigger studies and more long-term evidence鈥�

Perhaps one of the biggest questions is how much better a person鈥檚 own cord blood is compared with a stranger鈥檚. Although donated cord blood is more likely to be accepted by the immune system than adult stem cells, there is still a risk of rejection triggering potentially life-threatening graft-versus-host disease. That risk disappears if a person uses their own cells.

Your own cord blood isn鈥檛 always a silver bullet, though. If a person has a genetic disorder, their cord blood cells will carry the same mutation, and so will be useless as a treatment. But they could still benefit from the cord blood of a family member, which is also less likely to be rejected by their immune system.

So should you consider privately banking your baby鈥檚 blood in case they want to use it, sometime in the future? The treatment might not be possible today, but the field could look totally different in 20 years鈥� time, says Allan. 鈥淚 don鈥檛 know the answer right now,鈥� he says. 鈥淚t鈥檚 like buying insurance, I guess.鈥� Parents will have to look at the potential 鈥� and their finances 鈥� for themselves.

This article appeared in print under the headline 鈥淏anking on the future鈥�