On May 12th, according to reports, Richard Slayman, the first human recipient of a pig kidney transplant, passed away less than two months after the surgery at the age of 62. The research team at Massachusetts General Hospital (MGH) officially announced this news on May 11th. Professor Chen Zhonghua, from the Organ Transplant Research Institute of Tongji Hospital, Huazhong University of Science and Technology, and chief consultant of the Organ Procurement Organization (OPO) at Tongji Hospital, revealed that the patient died of heart disease on May 6th, as informed by the U.S. research team who performed the surgery. The cause of death was not directly related to the transplant's function. Previously, the research team estimated that the patient could live for at least two years or more. "Unfortunately, despite the patient 'surviving' through the hyperacute rejection of xenotransplantation, perioperative risks, infections, and early recovery stages, he could not 'survive' the heart issues possibly caused by various factors," said Chen Zhonghua. The patient had been suffering from uremia for 11 years, had undergone a previous allogeneic transplant, and also had hypertension and type 2 diabetes. After being discharged, the patient openly expressed during a follow-up visit, "Compared to the previous long-term dialysis, I can now eat and drink, feeling really good." Surgeon Tatsuo Kawai, who participated in the patient's surgery, mentioned that the operation to transplant a pig kidney to Slayman took four hours. Slayman's right kidney was a donated human kidney, as Kawai had performed an allogeneic kidney transplant for him in 2018, but this kidney had completely failed by 2023. Consequently, Slayman had to resume regular dialysis. However, he also had diabetes and cardiovascular complications, making him a candidate for xenotransplantation. Chen Zhonghua stated that compared to allogeneic organ transplants, xenotransplantation involves a more diverse and substantial immunosuppressive regimen, including unconventional medications approved by the U.S. Food and Drug Administration under compassionate use, which may increase the occurrence of postoperative cardiovascular events in patients. "The cause of the patient's death requires further scientific research and analysis, but at least we can currently rule out transplant kidney failure due to rejection reactions. The survival of over 50 days was not easy and holds significant milestone value," Chen Zhonghua remarked. "There is ample clinical evidence proving that genetic engineering technology can completely overcome the hyperacute rejection unique to xenotransplantation. However, the difficulties and issues encountered in the early stages of allogeneic transplants will be experienced again in this new era of xenotransplantation, requiring step-by-step efforts to overcome," Chen Zhonghua explained. Issues such as acute rejection reactions, chronic rejection reactions, various infections due to lowered immune responses, cardiovascular complications, liver and kidney damage caused by medication side effects, as well as the onset of new-onset diabetes or exacerbation of pre-existing diabetes after transplantation, all need to be addressed. Chen Zhonghua also disclosed that on April 24th, New York University Langone completed the world's second pig-to-human kidney transplant surgery. The patient is currently "doing well." This surgery marked the first-ever combined transplant of an artificial mechanical heart and pig kidney with thymus tissue from a pig. The patient was a 54-year-old woman suffering from end-stage heart and kidney failure. She had previously received a stent implant in her heart and undergone multiple catheter interventions. In 2020, she had part of her colon removed due to colon cancer. "We estimate that the second xenotransplant recipient may have a longer postoperative survival time. We hope that the thymus tissue and thymus cells simultaneously implanted can address postoperative mid-to-long-term immune rejection issues from another perspective," Chen Zhonghua concluded.
