Chinese scientists have achieved organ function of longer than six months in a macaque with a transplanted, gene edited, pig kidney, according to news reports, by Xinhua News, South China Morning Post, and the Global Times. This comes shortly after Harvard Medical School researchers transplanted a genetically modified pig kidney into a human with kidney failure. He died a couple months later.
The Chinese researchers are from an affiliated hospital of Tongji Medical College under the Huazhong University of Science and Technology. On May 10, the team used pCMV-negative four-gene edited pigs (GTKO/β4GalNT2KO/hCD55/hTBM) as donors to transplant a single pig kidney into a macaque, while removing both the macaque’s own kidneys.
The transplanted kidney survived 184 days, functioning well. In the first five months after the transplant with normal physiological readings. Chronic rejection set in after that point.
The researchers used what they described as an improved immunosuppressive regimen for the xenotransplantation. These scientists have not shared many details of their study, but the most common immunosuppressive agents used in xenotransplantation are the anti-CD154 antibody, mycophenolate mofetil. anti-thymocyte globulin, tacrolimus, rapamycin, cyclosporine, belatacept, abatacept, sirolimus, fingolimod and everolimus.
Chronic kidney disease is a progressive condition that affects more than 10% of the general population worldwide, or over 800 million people. While there are medications to control associated problems, such as high blood pressure and high cholesterol, many patients must go on dialysis.
This particular transplant is an important milestone for the Chinese, who hope to be competitive in this field. In animal studies involving grafting organs between different species, survival of 180 days is deemed a benchmark for long-term survival and needed to get approval for human trials. The team is planning to prepare for human clinical trials by curbing antibody responses for longer graft survival.
Activity in this field is picking up.
In 2023, Harvard affiliated scientists reported a study in which a kidney transplanted from a genetically engineered miniature pig kept a monkey alive for more than two years—one of the longest survival times for an interspecies organ transplant.
In 2022, researchers from The University of Alabama at Birmingham transplanted two kidneys from a pig into a brain-dead human in a proof-of-concept study.
Most striking, last March, Harvard Medical School physician-scientists transplanted a genetically modified pig kidney into a human with kidney failure. The 62-year-old man lived for two months.
