Scientists and surgeons at Duke University are winners of the 2023 Gizmodo Science Fair for pioneering a combination heart-thymus transplant procedure.
The Question
Can you convince a person’s immune system to accept a donated organ, without needing a lifelong course of anti-rejection drugs?
The Results
Duke University staff, led by Joseph Turek, chief of pediatric cardiac surgery, performed a first-of-its-kind procedure on 6-month-old Easton Sinnamon in the summer of 2021. Easton was born with severe heart problems that necessitated a transplant, but he was also afflicted with a severely underdeveloped thymus — a gland in the middle of our chest that helps certain immune cells mature.
Turek and his colleagues believed that Easton’s situation provided a unique opportunity to test a theory that had been on their mind for years. One of the main functions of the thymus is to help T cells learn how to tell friend from foe. They reasoned that giving someone a new heart and thymus from the same donor might allow the recipient’s immune system to recognise the heart as its own, which could then substantially reduce or completely eliminate the need for anti-rejection drugs.
The experimental procedure, specially approved by the Food and Drug Administration, was a resounding success. The now 2-year-old Easton is still doing well and meeting all of his developmental milestones on time. Tests have shown no signs of acute rejection, even as doctors have steadily reduced the amount of immune-suppressing drugs he’s taking. The typical regimen for a heart transplant patient is two drugs, but Easton is currently on only a half-dose of a single drug.
Why They Did It
“Easton is showing us that we can do this in an immunocompromised child. I believe that we will be able to almost reset the immune system in such a way that we can do these heart and thymus transplants even in patients with competent immune systems — and we’re working on that in the lab,” Turek said. “I think this could be the future of pediatric heart transplantation.”
Why They’re a Winner
One of the holy grails of the transplantation field is to find a permanent solution to organ rejection. And while Easton’s case is a very special one, the lessons learned from him may help get us there for many patients in the future.
Collaboration was key to this achievement. Decades earlier, Duke researchers led by Mary Louise Markert began the project that would someday allow donated thymus tissue to be safely processed and successfully transplanted into people — a technology approved by the FDA in 2021 to treat children born without a thymus.
“Over the next 20 years, we worked together to identify tissue characteristics of cultured thymus that were associated with successful immune reconstitution once it is implanted,” said Laura Hale, a Duke pathologist and immunologist who has long worked with Markert and is now working with Turek.
What’s Next
In mid-2023, the Duke team will run tests that should determine whether Easton’s immune system has truly become tolerant to the new heart. And if that goes well, they’ll try to completely wean him off treatment. They also hope to run clinical trials of the procedure within a few years.
The Team
Aside from Mary Louise Markert, Joseph Turek, and Laura Hale, the Duke University team involves dozens of researchers and medical staff across the fields of pathology, surgery, and even veterinary medicine. Easton’s care team alone comprises more than 25 people.