Boy’s stem cells used to rebuild windpipe
If successful, they believe it could lead to a revolution in regenerative medicine.
The operation, lasting nearly nine hours, took place at London’s Great Ormond Street children’s hospital on Monday but only emerged yesterday.
Stem cells taken from the boy’s bone marrow were injected into the fibrous collagen “scaffold” of a donor trachea, or windpipe. The organ, which had first been stripped of its own cells, was then implanted into the boy.
Over the next month doctors expect the stem cells to begin transforming themselves within the boy’s body into internal and external tracheal cells.
The boy, whose identity is being kept secret at the moment, is said to be doing well and breathing normally.
Because they are derived from his own tissue, there is no danger of the newly grown cells triggering an immune response.
With a normal transplant, rejection of the organ would necessitate dampening down the child’s immune system with suppressive drugs.
The procedure was a big step forward from the pioneering surgery conducted in Spain two years ago on 30-year-old mother-of-two Claudia Castillo, the first person to receive a transplant organ created from stem cells.
Ms Castillo was given a section of tracheal airway rebuilt from stem cells, but using a much more complex and costly process. On that occasion doctors grew the new tissue outside the body by rotating the donor graft in a special “bioreactor” before transplanting it into the patient’s body.
In the boy’s case, his own body acted as a living bioreactor.
The de-cellularised windpipe was treated with a carefully mixed cocktail of chemicals designed to trigger signals that would allow the tissue to grow in situ.
Professor Martin Birchall, head of translational regenerative medicine at University College London, said: “This procedure is different in a number of ways, and we believe it’s a real milestone. It is the first time a child has received stem cell organ treatment, and it’s the longest airway that has ever been replaced.
“I think the technique will allow not just highly specialised hospitals to carry out stem cell organ transplants.
“Now we need to conduct more clinical trials to demonstrate that this concept works. We’d like to move to other organs as well, particularly the larynx and oesophagus.
“Importantly we need to think about how to make regenerative medicine a key part of our healthcare.”
Preparation of the donor organ was carried out in the Great Ormond Street operating theatre by stem cell pioneer Professor Paolo Macchiarini, from Careggi University Hospital in Florence.
