A Historic, Yet Challenging, Xenotransplant Journey

In a landmark case highlighting both the promise and the hurdles of xenotransplantation, Towana Loni, a 53-year-old woman from Alabama, underwent the removal of a genetically modified pig kidney after it functioned for a record-setting 130 days. The transplant, performed on November 25, 2024, at New York University Langone Medical Center, initially offered Loni a reprieve from nine years of dialysis. Though, recent complications led to the arduous decision to discontinue the xenograft.

Unexpected Rejection and the Return to Dialysis

Following the transplant, Loni experienced a period of recovery aided by immunosuppressive drugs, allowing her to return home in February. Though, in late March, signs of rejection began to surface. On March 31st, Loni reported discomfort during urination, and subsequent tests revealed elevated creatinine levels, a key indicator of impaired kidney function. While doctors initially suspected dehydration, Loni’s creatinine levels rapidly worsened, prompting her return to the medical center for further evaluation.

Despite thorough inquiry, including ultrasound imaging, the cause of the kidney’s dysfunction remained elusive. Robert Montgomery, the lead surgeon, expressed surprise, noting the team believed they had overcome early rejection barriers. Ultimately,the medical team,in consultation with Loni,determined that removing the pig kidney and resuming dialysis was the safest course of action,preserving the option for future transplantation attempts.

Expert Analysis: A Step Forward Despite the Setback

Chen Zhonghua, a professor at the Institute of Organ Transplant of Tongji Hospital of Huazhong University of Science and Technology, characterized the event as both a “breakthrough” and a “setback” in the complex field of xenotransplantation. He suggested that a reduction in infection treatment, leading to a potentially irreversible antibody and/or cell-mediated rejection reaction, may have contributed to the kidney’s failure. this outlook aligns with the broader understanding of xenotransplantation, where managing immune responses remains a notable challenge.

130 days, this is undoubtedly a new breakthrough and a new ‘setback’ for the difficult field of xenografts… every xenograft exploration is to accumulate valuable experience for subsequent xenografts entering the clinical practice.
Chen Zhonghua, Professor at the Institute of Organ Transplant of Tongji Hospital of Huazhong University of Science and Technology

Currently, research into the specific reasons for the kidney’s loss of function is ongoing. Loni has since recovered from the removal procedure and has returned home, resuming dialysis treatment.

the Patient’s Perspective and the Future of Xenotransplantation

Despite the outcome, Loni remains optimistic and grateful for the chance to contribute to medical advancement. She expressed hope that her experience will inspire and assist other kidney patients in their fight against the disease.

I am very grateful for the opportunity to participate in this amazing study. Even though the results are not satisfactory, these 130-day experience in transplanted pig kidney survival will surely help and inspire more kidney patients to overcome the disease.
Towana Loni, Pig Kidney Recipient

The pig kidney used in Loni’s transplant was genetically modified by Revivicor, a subsidiary of United Therapeutics Corporation, to minimize immune rejection and thrombosis. This involved editing 10 key genes. This genetic modification represents a crucial step in making xenotransplantation a viable option for patients facing organ failure.

The Broader Context: Organ Shortage and the Promise of Xenotransplantation

The need for alternative organ sources is critical. According to the Organ Procurement and Transplantation Network (OPTN), as of April 2025, over 100,000 peopel in the United States are awaiting organ transplants, and many die each year while on the waiting list. xenotransplantation, the transplantation of living cells, tissues, or organs from one species to another, offers a potential solution to this critical shortage. While challenges remain, including immune rejection and the risk of cross-species infection, ongoing research and advancements in genetic engineering are paving the way for safer and more effective xenotransplantation procedures. Loni’s case, despite the setback, provides invaluable data and insights that will contribute to the progress of this vital field.