Duke University researchers say they’ve recently performed a pioneering organ transplant in a baby boy—one meant to help his body accept the new organ without the need for large doses of anti-rejection drugs. More than six months in, the baby’s immune system seems to be adjusting as expected, and he’s doing well. It’s possible that this method could one day make organ transplants in general safer and longer-lasting.
The procedure was performed last summer, with the FDA’s permission, on then 6-month-old Easton Sinnamon. Sinnamon was born with severe heart defects that left him in dire need of a transplant. But he also had a condition known as congenital athymia, which meant he was missing his thymus. The thymus plays a crucial role in our immune system, helping mature the T-cells that fend off foreign invaders like germs.
Normally, people who receive solid organ transplants require lifelong doses of immune-suppressing drugs to keep their bodies from attacking the organ. But some scientists have theorized that if you gave someone a new thymus at the same time as their donated organ (matched to the donor’s cells), the immune system could effectively be reset to recognize the donor organ as familiar, which would then reduce or even eliminate the need for anti-rejection drugs. This should ideally allow recipients to live longer with their organs and free of the many side-effects that come with these drugs, including a higher risk of life-threatening infections. Animal studies have shown that this method has promise, but we haven’t reached the point of studying it in humans yet.
As luck would have it, though, the Duke team had been working for years on a way to safely process and transplant donated thymus tissue to children born without one. (Their technology, licensed to Enzyvant Therapeutics GmbH, was approved by the FDA in October 2021). Because Sinnamon needed both a new thymus and a new heart, his case provided a natural opportunity to test out this theory. As far as the doctors know, he’s the first to receive this dual transplant.
So far, things appear to be going well. Tests taken about six months following the procedure suggest that Sinnamon’s new thymus is working, producing new T-cells. His health is good otherwise, and he just recently celebrated his first birthday.
“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 immune-suppression medications, which can be highly toxic, particularly to the kidneys,” said Joseph Turek, chief of pediatric cardiac surgery at Duke and a member of Sinnamon’s surgical team, in a statement from the university.
The real test will likely come in a few months, when the doctors hope to start tapering Sinnamon off his current anti-rejection drugs. But if things continue to look good, it could prove to be a monumental leap forward for the organ transplant world. “This concept of tolerance has always been the holy grail in transplantation, and we are now on the doorstep,” Turek said.
This isn’t the only novel way that doctors are trying to innovate organ transplantation as of late. Researchers across the U.S. have been experimenting with genetically engineered pig organs—so far, kidneys and hearts—made to be more compatible with humans, in hopes of expanding the constantly short supply of available organs.