January 28, 2008

Transplant Recipient Adopts Organ Donor’s Immune System

Demi-Lee Brennan, a 15-year-old Australian transplant recipient has become the first person in the world to change blood groups and assume the immune system of her donor.

"It's like my second chance at life," said Brennan.  "It's kind of hard to believe," she added, speaking of how her body achieved what doctors called a "one-in-six-billion miracle."

Brennan received her liver transplant six years ago at age 9 after her own liver had failed.  She changed blood group from O negative to O positive after she became ill while on drugs to avoid rejection of the organ by her body's immune system.

Her new liver's blood stem cells then invaded her body's bone marrow and took over her entire immune system, meaning the teen no longer needs anti-rejection drugs.

In the latest edition of The New England Journal of Medicine, doctors from Sydney's Westmead Children's' Hospital explained they had no explanation for Brennan's recovery.  "There was no precedent for this having happened at any other time, so we were sort of flying by the seat of our pants," Michael Stormon, a pediatric hepatologist, told said in a local radio interview.

Stuart Dorney, the hospital's former transplant unit head, said in a Reuter's article that Brennan's treatment could lead to breakthroughs in organ transplant treatment, because normally the immune system of recipients attacked the transplanted tissue.  "We now need to go back over everything that happened to Demi-Lee and see why, and if it can be replicated," he said.

"We think because we used a young person's liver and Demi-Lee had low white blood cells, that could have been a reason," he told the Daily Telegraph newspaper.

In Australia, only 70 percent of transplant operations are successful after a five-year period due to rejection complications.  While rejection is typically treated with a combination of drugs, chronic rejection is irreversible.

A summary of the article appearing in this week's New England Journal of Medicine can be viewed at http://content.nejm.org/cgi/content/short/358/4/369