We can create a mouse with a human liver. So, no longer any need to face up to the tricky subject of organ donation, right? Wrong. One of the dangers of such achievements is that we begin to think that a solution to the organ crisis is just around the corner.
The Japanese mouse-human chimera  involved taking adult stem cells from human skin and chemically inducing them to return to their “pluripotent” state, where they can become any kind of cell. Further treatment guided them to take the form of liver cells, which were then grafted into the mouse. There, they connected to the blood vessels and formed into a functioning human liver.
The work built on an idea first put forward by the US geneticists Tim Townes and Thomas Ryan in 2000 . They spotted that knocking out certain genes and inserting genetic material from an afflicted patient allowed you to rear an animal whose heart, liver, pancreas or blood or skin cells were human – that were genetically matched to the recipient and were in every way perfect for transplantation.
By coincidence, Townes and Ryan submitted their patent application on the day after Sally Slater was discharged from a hospital in Newcastle. Slater, aged six, had undergone an emergency heart transplant after a virus attacked her cardiac tissue. Her donor was a recently deceased, middle-aged woman whose family came forward to help after Slater’s father issued an emotional appeal through the national media.
Every year in the UK, a hundred or so families go the other way and overrule the wishes of a deceased relative who had wanted to donate his or her organs. In the decade that it might take for the Japanese success to make any headway into patient treatment, more than a thousand families could dash the hopes of the desperately ill. That’s in this country alone, where more than 7,000 people are waiting for transplants. A thousand of them will die this year because of a lack of organs. Slater, now a thriving 19-year-old with a 62-year-old heart, has been vocal and active in drawing attention to the shortfall, encouraging more people to sign up for organ donation .
Things might get a little better after the 2 July decision by the Welsh Assembly to adopt “presumed consent” for organ donatio n. After 2015, people in Wales who don’t want their organs recycled will have to sign the opt-out register. Somewhat perversely, organs from Wales will be available to patients in the rest of the UK, which remains opt-in after a 2008 review concluded that opt-out was unlikely to increase the number of donated organs and risked reducing their availability IN THE FRAME by undermining trust in the medical profession.
Britain has one of the highest refusal rates in Europe, with half of all families denying organs if the deceased’s wishes are not known . In some ways this is understandable. It is only 45 years since the first UK liver transplant and 30 since our first heart-and-lung transplant . That is a very short time, in human terms, in which to contemplate changes to our death rituals.
Nonetheless, we should do better with what science has provided – regardless of what is coming. A mouse with a human liver is extraordinary indeed. But scientists have also made great strides in learning how to perform transplants, how to suppress the immune system’s rejection of foreign tissue and how to care for those who have gone through such traumatic procedures.
It would be a terrible shame if the advances of stem-cell research were to provide any further excuse for refusing to save a life.