Successful Pig Liver Transplant Offers Hope for Patients with Failing Livers
In a groundbreaking experiment, surgeons at the University of Pennsylvania have successfully attached a genetically altered pig liver to a brain-dead person, demonstrating that the organ can function normally for 72 hours. This achievement represents a significant step forward in the use of pig organs to assist extremely ill patients with failing livers.
Liver failure is a serious medical condition that can result from alcohol abuse, viral infections, obesity, and drug overdose. Each year in the United States, over 330,000 people require treatment for liver failure. While some individuals can recover with proper care, those with long-term damage often need a liver transplant. Unfortunately, the demand for livers far exceeds the supply, with more than 10,000 patients currently on the waiting list in the US alone.
The experimental procedure involved keeping the brain-dead patient on a ventilator while a pig liver was placed outside the body in a device called a perfusion machine. Tubes circulated the patient’s blood through the pig liver, which produced bile and maintained normal blood acidity. The patient remained in stable condition throughout the three-day period of observation.
The use of animal organs, particularly from pigs, has long been explored as a potential solution to the organ shortage crisis. Pigs are readily available and have similar-sized anatomy to humans. However, their organs are not naturally compatible and would typically be rejected by the human immune system upon transplantation.
To address this issue, researchers have genetically altered pigs to make their organs more compatible with humans. In this study, the pig used had undergone 69 genetic edits, including knocking out three pig genes to prevent immediate immune rejection and inserting seven human genes involved in inflammation, immunity, and blood clotting. The remaining edits disabled innate viruses found in the pig genome that could potentially infect humans.
Previous attempts at using pig livers to support patients with liver failure were largely unsuccessful, with the organs failing within a matter of hours. However, the genetically modified pig liver used in this study demonstrated stable blood flow and pressure, with no signs of inflammation. The researchers believe that further refinement of the procedure and additional genetic modifications could potentially extend the period of support for patients.
The team at the University of Pennsylvania plans to conduct further experiments on brain-dead individuals to refine the procedure. The biotech company responsible for breeding the genetically modified pig, eGenesis, is also in discussions with the FDA regarding plans for an early-phase trial to use their pig system on patients with liver failure. Additionally, they are considering one-off experiments in sick patients through the FDA’s “compassionate use” program.
While this breakthrough offers hope for patients with failing livers, there are still many challenges to overcome. The complex immune responses involved in longer organ replacements need to be carefully studied, and more research is needed to determine the optimal combination of genetic modifications and perfusion devices to support living patients.
Despite these challenges, the successful pig liver transplant represents a significant advancement in the field of organ transplantation. It offers a glimmer of hope for those on the waiting list and paves the way for further innovation in addressing the organ shortage crisis. With continued research and development, pig organs may soon become a viable option for patients in need of life-saving transplants.
