Are pig organs the future of transplants?

We all know about organ transplants; you take organs from someone who doesn't need them anymore and transplant them into a human whose organs have stopped working. It is a simple concept, but what happens when there are more people in need of organs than there are available? This is unfortunately the reality of many people that are waiting for kidney transplants. Approximately 100,000 people are on the kidney transplant waiting list in the U.S. but only 20,000 kidneys are available yearly. This causes a big problem considering that most of those patients must live on dialysis, making it harder for them to have a normal life. 

The solution to this problem might be xenotransplants. This basically means transplanting non-human animal tissue, organs or live cells into the human body. Scientists mainly use porcine (pig) organs for these procedures because of their similarity to human organs. Before xenotransplanting kidneys there had already been 2 failed attempts of transplanting porcine hearts into human beings, tragically, both patients died within 2 months of the procedure. 

To make the transplants work scientists had to genetically modify the pig kidneys to make them even more similar to the human ones and drastically decrease the rate of rejection.  To do that a technique called clustered regularly interspaced short palindromic repeats or CRISPR that allows scientists to make precise changes in cells, in total 69 different genetic changes were made to remove porcine genes that cause immediate rejection in the human body, and to add new genes in the kidneys to make them more like human organs. 

The first successful pig kidney transplant happened on the 16th of March; the recipient was a 62-year-old man called Richard Slayman who suffered from end-stage kidney disease (ESKD). He had already received a transplant from a human donor in 2018 but the organ failed 5 years later. Slayman also suffered from type II diabetes which complicated the process of finding a second human donor. The 4-hour-long procedure was done in Massachusetts General Hospital (MGH), and it is considered to be a success and groundbreaking procedure in transplant surgery. 

Unfortunately, Mr. Slayman died 7 weeks after receiving the kidney, doctors at MGH claim that his death was unrelated to the kidney transplant and states “"Mr. Slayman will forever be seen as a beacon of hope to countless transplant patients worldwide and we are deeply grateful for his trust and willingness to advance the field of xenotransplantation...”. There were no signs of organ rejection, but the cause of death hasn't been made public. 

To conclude, xenotransplantation is still an experimental but promising field of medicine that if further developed has the potential to save the lives of thousands of people.