Transplant girl who has turned medical science on its head

HAVING come through a liver transplant at the age of nine, Demi-Lee Brennan expected she would have to take powerful drugs for the rest of her life to stop her body rejecting the donated organ.

But the youngster has amazed her doctors and is now able to live without the medication, in what experts describe as a "one-in-six-billion miracle".

Demi-Lee, now 15, is thought to be the first patient ever to take on her donor's immune system, even swapping blood groups after her transplant operation.

It means that she can now get on with fulfilling her dream of becoming a rock star.

Demi-Lee's problems began in 2001 after a viral infection caused her liver to fail. The young girl, from Sydney, Australia, was lucky enough to receive a donor liver from a 12-year-old boy who died from a brain injury.

But nine months later, she became seriously ill with a condition known as pneumolysis, which causes the red blood cells to break down.

Tests were carried out which revealed the first surprise – her blood group had changed from O-negative to that of her donor, O-positive.

Doctors at the Westmead Children's Hospital were then amazed to find that stem cells from the new liver had penetrated Demi-Lee's bone marrow, leading to a kind of natural bone marrow transplant.

Her immune system had almost totally been replaced – to the extent that she no longer had immunity to diseases she was immunised against as a baby.

Her new condition meant she no longer needed to take the drugs to stop her body rejecting the donated liver – drugs which over time can cause organ damage and infection.

Dr Julie Curtin, the hospital's head of haematology, described her patient's transformation as the "holy grail of transplants".

Demi-Lee's doctor, Michael Stormon, said their team was now trying to identify how the phenomenon happened to see whether it could be replicated in other patients.

He said: "That's probably easier said than done ... I think it's a long shot. I think it's a unique system of events whereby this happened."

It is hoped that, as well as transplant patients, studying Demi-Lee's immune-system swap could also help sufferers from immune diseases like multiple sclerosis and Type 1 diabetes.

Far from stepping out of the spotlight after making medical history, Demi-Lee is now hoping to appear on Australian Idol – their version of Pop Idol.

"I feel quite normal, it's almost like it never happened," she said. "I can't thank the donor's family enough, and the doctors, for giving me this second chance at life."

UNHEARD-OF SITUATION

Dr Andrew Bathgate

FOR a transplant patient to adopt the immune system of the donor is completely unheard of.

What is known is that there can be a mixing of the immune cells outside of the transplanted organ, which is known as "chimaerism".

If you look for the cells of the donor outside the liver, you can usually find them. But that is very different from the stem cells of the donor liver penetrating the bone marrow, as appears to have happened here.

There has been some work done in adult transplantation to try to improve the acceptance of donor livers by also using bone marrow from the donor. But so far, this technique has not met with great success.

What appears to have happened in the Australian patient is quite different. It offers doctors the opportunity to study what has happened in this case to see if it can help other patients. If they can find the mechanism by which this occurred, it would be a significant advance.

• Dr Andrew Bathgate is a consultant transplant physician at Edinburgh Royal Infirmary.