Baby receives world first ‘heart-thymus’ transplant

Experts said that the procedure could ‘change the face of solid organ transplantation’.

08 March 2022

A baby has received the world’s first heart transplant combined with a thymus implant – a procedure which has the potential to change the future of organ transplants.

Easton Sinnamon is said to be “thriving” after the procedure, which it is hoped will lower the risk of his body rejecting his new heart and could potentially mean that he does not need to rely on life-long immunosuppressant drugs.

Doctors think that thousands of patients could potentially benefit in the future.

The thymus is a gland in the chest which makes white blood cells called T cells. They play an important role in the body’s immune system, which helps to fight infections.

When the immune system detects a foreign body it can send these white blood cells to fight off what is believed to be an infection.

This is why when a person receives an organ transplant they need to take immunosuppressant drugs to prevent their immune system from rejecting the new organ.

But taking these drugs over a long period can weaken a person’s immune system and make them extremely vulnerable to even mild infections.

So experts have been looking for a way to reduce the reliance on immunosuppressant drugs after transplant.

And one possible avenue was implanted thymus tissue.

It is hoped that by transplanting a heart and thymus tissue from the same donor, that the thymus will be tricked into believing that the new heart is not a foreign body.

So one benefit is that the recipient’s body does not “reject” the donated organ.

Another potential bonus could mean that people no longer need to take life-long immunosuppressant treatments.

Experts at Duke University in the US have been exploring the possibility with animals but now they have tried the treatment on a human for the first time.

They performed the procedure on Easton last summer at Duke University Hospital in North Carolina.

“If this approach proves successful – and further validation is contemplated – it would mean transplant recipients would not reject the donated organ and they would also not need to undergo treatment with long-term immunosuppression medications, which can be highly toxic, particularly to the kidneys.

“This concept of tolerance has always been the holy grail in transplantation, and we are now on the doorstep.”

Dr Joseph Turek, Duke’s chief of paediatric cardiac surgery and a member of the surgical team that performed the landmark procedure, said: “This has the potential to change the face of solid organ transplantation in the future.

“If this approach proves successful – and further validation is contemplated – it would mean transplant recipients would not reject the donated organ and they would also not need to undergo treatment with long-term immunosuppression medications, which can be highly toxic, particularly to the kidneys.

“This concept of tolerance has always been the holy grail in transplantation, and we are now on the doorstep.”

He added that in the future this type of transplant could potentially benefit “thousands and thousands” of patients.

The thymus tissue implantation method, pioneered at Duke by Dr Louise Markert, uses a technique to culture and administer processed thymus tissue.

Baby Easton had the surgery last year when he was just six months old.

Easton, who is now one, was born with severe heart defects and a thymic deficiency which impaired his immune system.

He received his heart transplant on August 6 last year and the implantation of the cultured thymus tissue from his heart donor two weeks later,

Medics said that the combination of procedures “appears to be working”.

He continues to be monitored and it is hoped that in the future he will be taken off the anti-rejection drugs.

“It was one of those things where it could help him, and if it works, it not only helps him, but it could help thousands of other people as well with their children who need transplants,” said his mother Kaitlyn.

“When we talked about it, it was like ‘Why would we not do it when we can make a difference for all these other people?’”

Dr Allan Kirk, chair of the Department of Surgery at Duke University School of Medicine, added: “This case has implications for more than just heart transplantation – it could change the way that many solid organ transplants are done in the future.

“If this can be extrapolated to patients who already have a functioning thymus, it could potentially allow them to restructure their immune systems to accept transplanted organs with substantially less dependence on anti-rejection medication.”