In a groundbreaking development in the field of xenotransplantation, Chinese medical professionals have successfully transplanted a gene-edited pig's liver into a living patient. This landmark procedure, carried out at Anhui Medical University's First Affiliated Hospital, represents a significant advancement in the burgeoning field of animal-to-human organ transplants.
The 71-year-old recipient, who was suffering from severe liver cancer, received the transplant on May 17, with the successful outcome announced via the hospital's WeChat platform seven days post-operation.
In previous research by USA scientists, the modified kidney was provided by eGenesis, a xenotransplantation therapy company co-founded by HMS geneticist George Church and former HMS postdoctoral fellow Luhan Yang. Over the past five years, Mass General and eGenesis have conducted extensive research, with findings published in Nature in Oct. 2023.
As of May 24, the patient exhibited promising recovery signs: the ability to walk unassisted, the absence of hyper-acute or acute rejection responses, stable coagulation system functionality, and normalized liver function. This achievement underscores the potential of xenotransplantation to address critical shortages in human organ donations, a growing global issue.
This successful liver transplant follows other notable milestones in the field. In March, a team from China's Air Force Medical University transplanted a gene-edited pig's liver into a patient who had suffered brain death, marking another first in the domain. Concurrently, the United States saw its first genetically modified pig's kidney transplant performed on a living patient. Although this patient, who was in end-stage kidney failure, passed away earlier this month, Massachusetts General Hospital clarified that his death was not related to the transplant procedure.
The complexity of liver functions—which include metabolism, detoxification, and immune regulation—presents unique challenges in xenotransplantation. The liver's multifaceted role has led some U.S. researchers to speculate that its comprehensive functionality might be too robust for successful cross-species transplantation. However, the recent success in China challenges this notion and suggests that advancements in gene-editing and transplantation techniques may overcome these hurdles.
The Anhui Medical University team utilized a pig's liver that had undergone ten specific gene edits designed to prevent organ rejection and dysfunction. This meticulous genetic modification process is crucial for the viability of xenotransplants, as it addresses the human immune system's tendency to reject foreign organs. The 514-gram liver was transplanted after it was confirmed that the patient's own liver was incapable of sustaining life due to a large, non-responsive tumor.
Post-surgery, the transplanted liver was reported to secrete approximately 200 milliliters of bile daily, indicating functional integration into the patient's body. Imaging scans confirmed normal blood flow in the hepatic artery, portal vein, and hepatic vein, critical indicators of a successful transplant. According to the hospital's director, Sun Beicheng, these positive outcomes signal a significant step toward the clinical application of pig liver xenotransplantation.
This recent success places Chinese scientists at the forefront of xenotransplantation research and technology, potentially marking one of the most critical breakthroughs in modern medical science. The Chinese organ transplant ethics committee sanctioned the study, considering the patient's dire condition and lack of alternative treatments. This ethical approval highlights the delicate balance between innovative medical research and patient welfare.
The potential of xenotransplantation to alleviate the global organ shortage crisis is immense. According to the World Health Organization, thousands of patients die annually while waiting for organ transplants due to the limited supply of human organs. Xenotransplantation could provide a sustainable and scalable solution to this critical issue. However, the practice is not without its ethical and medical challenges. Concerns persist regarding the risk of organ rejection, the long-term viability of animal organs in human bodies, and the potential for zoonotic disease transmission.
As the field progresses, rigorous ethical standards and robust clinical trials will be essential to address these concerns. The promising developments in both China and the United States highlight the potential of xenotransplantation to revolutionize organ transplantation and offer new hope to patients worldwide. With continued advancements in genetic engineering, immunosuppressive therapies, and surgical techniques, xenotransplantation may soon transition from experimental procedures to routine clinical practice, fundamentally transforming the landscape of transplant medicine.