The University of Alabama published the first peer-reviewed research outlining the successful transplant of genetically modified, clinical-grade pig kidneys into a brain-dead human individual, replacing the recipient’s native kidneys.

About the study

UAB researchers tested the first human preclinical model for transplanting genetically modified pig kidneys into humans. The study recipient had two genetically modified pig kidneys transplanted in his abdomen after his native kidneys were removed. The organs were procured from a genetically modified pig at a pathogen-free facility.

Although dialysis can sustain life for some time, transplantation offers a better quality of life and a longer life for the few individuals who can gain access to transplantation. 

Each stage of this decedent xenotransplant study approximated the steps that might be taken in a Phase I xenotransplant clinical trial:

  • The kidneys were removed from a donor pig housed at a pathogen-free, surgically clean facility. The kidneys were then stored, transported and processed for implantation, just as human kidneys are.
  • Before surgery, the brain-dead recipient and donor animal underwent a crossmatch compatibility test to determine whether the genetically modified pig kidney and its intended recipient were a good tissue match.
  • The pig kidneys were placed in the exact anatomic locations used for human donor kidneys.
  • The brain-dead recipient received standard immune-suppression therapy used in human-to-human kidney allotransplantation.

The study was conducted to meet the standards directly comparable to those that would apply to a Phase I human clinical trial, mirroring every step of a standard transplant between humans. 

How was it done?

For the first time, the pig kidneys transplanted were taken from pigs that had been genetically modified with 10 key gene edits that may make the kidneys suitable for transplant into humans.

The transplanted kidneys filtered blood, produced urine and, importantly, were not immediately rejected. The kidneys remained viable until the study was ended, 77 hours after transplant.

Is the procedure safe?

Genetically modified pig kidneys have been extensively tested in non-human primates. In addition to testing in non-human primates, evaluating genetically modified pig kidneys in a human preclinical model research may provide important information about the potential safety and efficacy of kidneys in human transplant recipients, including in clinical trials.

“Our study demonstrates that major barriers to human xenotransplantation have been surmounted, identifies where new knowledge is needed to optimize xenotransplantation outcomes in humans, and lays the foundation for the establishment of a novel preclinical human model for further study” Locke added.

The harsh reality of kidney diseases 

Kidney disease kills more people each year than breast or prostate cancer. 

Although transplantation is the gold standard treatment for end-stage kidney disease, fewer than 25,000 kidney transplants are performed each year in the United States and 240 Americans on dialysis die every day. 

The wait for a deceased donor kidney can be as long as five years, and in many states, it is closer to 10 years. Almost 5,000 people per year die waiting on a kidney transplant.

Src: UAB