The first successful pig kidney transplant into a human
Ana Anajuba discusses the recent success of the transplantation of a pig kidney into a human patient, why this process has failed in the past and what the benefits of animal-human organ transplants are.
When thinking of the transplantation of an animal organ into a humans (Xenotransplantation), many would recall the well-known novel Pig Heart Boy by Malorie Blackman. Now, after the successful transfer of a pig kidney into a human patient in September 2021 by Dr. Robert Montgomery and the surgical team at NYU Langone Health in New York City, this is no longer just a concept but much closer to becoming reality.
Xenotransplantation has been attempted for centuries, originating in the 17th Century with blood transfusions but has become more successful over time up to the 20th Century with the notable case of Baby Fae, a dying infant, living 21 days with a baboon’s heart. Pig heart valves have also been used in humans for decades and Chinese surgeons have successfully transplanted pig corneas into human recipients previously.
To prevent the pig kidney from being immediately rejected by the human body, due to the presence of a sugar (alpha- gal) in pig cells which is rejected by the human body, the animal was genetically edited to remove this sugar which triggers an attack from the human immune system. Prior to inserting the kidney into humans for the first time, the surgeons attached it to a pair of large blood vessels outside the body of a brain-dead patient, who had signs of kidney failure and whose family consented to the experiment before she was taken off life support. During these tests, the kidney functioned as normal, filtering waster and producing urine as it was meant to be.
This successful transplant comes as a huge win for Revivicor, a subsidiary of United Therapeutics, who engineered the pig at a facility located in Iowa. It also provides a new hope for the 90,000 patients waiting on the transplant list in the USA, although the FDA would need more paperwork submitted by developers before pig organs could be transplanted into living human beings.
90,000 patients waiting on the transplant list
Ethically, it may be questionable. Using animal organs raises moral and religious dilemmas for some people, however, it is likely a saving grace for those who need a transplant as the current average waiting time for a kidney transplant is 3-5 years in America, and 2-3 years in the UK. There are now an increasing number of companies specialising in biotechnology that are in the arms race to develop non-rejectable pig organs to subsidise the current human organ shortage.
Current waiting time for a kidney transplant is 3-5 years in America, and 2-3 years in the UK
However, there is still a long way left to go as this only involved a single transplant with the organ only remaining in place for three days and future trials are likely to uncover new barriers that they will need to overcome. There is also considerable difficulty as the family would need to be consulted before allowing the doctors temporary access to brain-dead patients.