Xijing Hospital Major Research Achievement Published in Nature

Background

A global shortage of donor organs for transplantation has long been a major challenge in medicine. Pig organs have been explored as potential alternatives through xenotransplantation, with prior successes reported for hearts and kidneys in human recipients. Livers present additional complexities due to their metabolic roles and susceptibility to immune responses.

What was achieved

Researchers at Xijing Hospital performed what is reported as the world's first gene-modified pig-to-human liver xenotransplantation. The procedure took place on March 10, 2024, involving a liver from a six-gene-edited Bama miniature pig transplanted into a 50-year-old brain-dead man who had suffered a severe head injury. The pig liver was placed heterotopically as an auxiliary organ alongside the recipient's intact native liver.

Over the subsequent 10 days, the graft produced bile beginning two hours after reperfusion, with output reaching 66.5 ml by postoperative day 10. Porcine-derived albumin levels increased, key liver enzymes remained largely stable after an initial rise in aspartate aminotransferase, and blood flow through the graft's vessels stayed adequate. There were no signs of hyperacute rejection, and histological analysis confirmed intact liver architecture without evidence of rejection or significant inflammation. The study was terminated on day 10 at the family's request. The results were published in the journal Nature on March 26, 2025 (volume 641, pages 1029–1036), with lead authors including Kai-Shan Tao and Lin Wang from the Department of Hepatobiliary Surgery.

How it works

The donor was a seven-month-old male Bama miniature pig provided by Clonorgan Biotechnology. It received six genetic modifications: knockout of three pig genes (GGTA1, CMAH and B4GALNT2) that produce cell-surface sugars triggering strong human immune attacks, plus insertion of three human transgenes (CD46, CD55 and THBD) to regulate complement activation and reduce thrombosis risk. These edits aimed to prevent immediate graft destruction.

In heterotopic auxiliary transplantation, surgeons connected the pig liver to the recipient's blood supply without removing the native human liver. The surgery lasted more than 10 hours. The pig liver was linked to vessels including the portal vein and inferior vena cava, allowing it to receive blood and perform functions in parallel. Postoperatively, the team used ultrasound to monitor blood flow velocities, tracked laboratory markers for liver function, coagulation, inflammation and immune activation, and conducted biopsies. Immunosuppressive medications were administered. The graft immediately secreted golden-yellow bile and synthesized porcine proteins, demonstrating short-term physiological activity in the human body.

What it means for international patients

The study was conducted under strict ethical oversight in a brain-dead recipient as an experimental protocol to assess graft function and safety. It does not constitute routine clinical treatment for living patients with liver disease. The work demonstrates that a gene-edited pig liver can avoid hyperacute rejection and perform basic physiological tasks such as bile production and protein synthesis for a limited period, potentially informing future research into bridging therapies for organ failure.

Xijing Hospital operates an international ward with English-speaking coordinators and interpreter services and has experience treating patients from overseas, including from the Middle East, Central Asia and Southeast Asia. International patients interested in the hospital's liver care, transplantation programs or developments in this field should contact the hospital directly to confirm current availability, eligibility criteria and any applicable protocols. Patients must verify all details with the facility, as experimental approaches like xenotransplantation require individualized medical assessment.

About the hospital

Xijing Hospital, also known as the First Affiliated Hospital of Air Force Medical University (previously Fourth Military Medical University), is located in Xi'an, Shaanxi Province. Founded in 1939, it is a large Class A tertiary general teaching hospital with approximately 2,600 beds that combines clinical care, education, research and prevention.

It maintains nine national key disciplines and 17 national key clinical specialties, with particular strengths in organ transplantation, hepatobiliary surgery, digestive diseases (including a National Clinical Research Center), burns, orthopedics and cardiovascular care. The hospital has pioneered multiple innovative procedures in transplantation and related fields and is affiliated with military medical research institutes. It serves international patients through a dedicated international ward offering coordinator and language support.