Leslie Collins, M.D., Assistant Professor in Pediatric Cardiology, earned her medical degree at the East Carolina University – Brody School of Medicine. Dr. Collins completed her pediatric residency and pediatric cardiology fellowship at the University of Alabama at Birmingham. Her research/clinical interests include imaging, fetal ECHO, and heart failure and transplant.
Austin Kane, M.D.,AssistantProfessor in Pediatric Cardiology, earned his medical degree at Columbia University College of Physicians and Surgeons in New York, New York. Dr. Kane completed his pediatric residency at Northwestern University Feinberg School of Medicine in Chicago, Illinois. He completed a fellowship in pediatric cardiology at Emory University School of Medicine in Atlanta, Georgia and an additional fellowship in pediatric and congenital electrophysiology. Prior to joining the University of Alabama at Birmingham, he was a pediatric and congenital electrophysiology attending at Providence Sacred Heart Medical Center and Children’s Hospital in Spokane, Washington.
Khalisa Syeda, D.O., AssistantProfessor in Pediatric Cardiology, earned her medical degree at the University of North Texas in Fort Worth, Texas. Dr. Syeda completed her pediatric residency at the University of Illinois at Chicago and her pediatric cardiology fellowship at the University of Texas Health Science Center in Houston, Texas. Her research/clinical interests include pediatric cardiology, imaging, fetal echocardiography and preventive cardiology.
The issue is simple: there are simply not enough hearts for all the children who need them. So 17% of all children who need a heart transplant die while waiting; this translates to 20% to 25% of infants.
The University of Alabama at Birmingham (UAB) and Children’s of
Alabama aim to change those dismal statistics with one of the most
revolutionary approaches since the first heart was transplanted from one human
to another in 1967 – xenotransplantation.
Thanks to a $19.5 million grant from biotechnology magnate United
Therapeutics Corporation, UAB and Children’s have launched one of the top
programs in the world dedicated to developing genetically modified solid organs
from pig models for transplantation.
The idea isn’t
new. Pig tissue has been used to replace heart valves for years, said cardiothoracic
surgeon David Cleveland, M.D., MBA, who leads the program at Children’s. The
greatest challenge with solid organs, he said, is overcoming immunological and
If they can do that, “We believe that there’s huge potential to
improve the lives of children,” he said.
Earlier this year, Cleveland presented preliminary results from a
study showing little reactivity in an infant’s blood to cells from a
triple-knockout (TKO) pig. The pig had been genetically modified to delete the
three major antigens that react with natural human anti-pig antibodies. Even
those human cells that did react demonstrated a very mild reaction.
“We found that very promising,” Cleveland said.
Another area of interest is producing immune tolerance by
transplanting porcine thymus tissue to “re-educate” the immune system to accept
the pig heart, said cardiac intensivist Leslie
Rhodes, M.D. The idea comes from the fact that children can develop an immune
system via a human thymus transplant. “We wonder if we could we train their
immune system to be tolerant to the pig thymus transplant,” she said.
Infants are the ideal starting place, Cleveland said, not only because they have the highest wait list mortality of any other demographic waiting for a solid organ transplant, but because their immune systems are still naïve. Indeed, they do not develop antibodies to pig glycans during at least the first three months of life, Cleveland and his team wrote in a recent journal article, providing a “window of opportunity” for the transplant.
The next step is a transplant in a non-human primate. “The FDA
won’t even consider it until we can prove consistent survival in a non-human
primate,” Rhodes said. They hope to perform their first transplant later this
Societal Concerns Addressed
The team is also aware of the societal issues around
xenotransplantation. To address that, they surveyed the families of patients on
the transplant list and the nurses and physicians who will care for these
”I was surprised by how positive they were,” Cleveland said. “I
thought there would be more pushback than there was.” Still, he said, “I think there
has to be major education,” once xenotransplantation becomes a reality. “The
idea of replacing a heart with a pig heart will take some people a little time
to get over.”
He’s confident it will happen, though. “UAB is going to be one of
the centers in the world with the potential to make this happen,” he said. “We
have children living in our ICU because there’s not enough cardiac function; they
are having their birthdays here. It totally changes entire families to have a
child in the hospital forever. There has to be another way.“
 Dipchand AI. Current state of pediatric cardiac transplantation. Ann Cardiothorac Surg. 2018;7(1):31–55. doi:10.21037/acs.2018.01.07
 Cleveland D, Adam Banks C, Hara H, Carlo WF, Mauchley DC, Cooper DKC. The Case for Cardiac Xenotransplantation in Neonates: Is Now the Time to Reconsider Xenotransplantation for Hypoplastic Left Heart Syndrome? Pediatr Cardiol. 2019;40(2):437-444.