Each year, thousands of people perish while waiting for an organ transplant. Xenotransplantation pioneers are cautiously optimistic that breakthroughs could soon make significant strides in overcoming past hurdles.
In the United States, a staggering 100,000 individuals currently await placement on the organ transplant waiting list, with a distressing 17 lives lost each day prior to receiving a life-saving organ. Despite the chronic shortage of organ donors, medical professionals have long explored the possibility of xenotransplantation – a procedure that involves transplanting tissue or organs from animals into humans.
While early research was marred by ethical concerns, the idea persisted as an outsider in mainstream medicine. The fear of rejection looms large, leading to this outcome. Despite posing challenges for human transplants, the risks are significantly higher when using organs from other species.
As genetic engineering techniques continue to advance in precision and effectiveness, they are increasingly bringing the concept into the mainstream. Researchers have expressed optimism that the technology to edit donor animals’ DNA, thereby preventing the production of biomolecules known to trigger immune responses in humans, could be effective in all circumstances.
Recently, groundbreaking studies have shown that genetically modified pig organs can function temporarily and seamlessly within the human body. Despite the challenges posed by medical complications, organ rejection, and mortality, recent advancements in this field have yielded encouraging results.
At Massachusetts General Hospital, over 1,400 patients languish on the waiting list for a life-saving kidney transplant, a stark reminder of the dire need for innovative solutions.
As a dire consequence, some unfortunate patients will tragically succumb to their illness or become too frail to undergo transplantation due to the prolonged wait endured on dialysis treatment. Xenotransplantation offers significant promise in addressing the pressing issue of organ scarcity.
In 2021, a groundbreaking medical breakthrough took place when doctors successfully transplanted a genetically engineered pig organ into a patient who had been brain-dead for some time. Researchers successfully silenced the gene coding for alpha-gal, a molecule responsible for triggering organ rejection, within a donor pig’s workforce. Although the surgery initially appeared successful, with the kidney producing urine and showing no signs of rejection, the patient’s life was only prolonged for 54 hours.
A patient with terminal cardiac disease, who initially showed promise but unfortunately succumbed to their condition 60 days later. While investigating the cause of his death, medical professionals found that prescreening tests failed to detect porcine cytomegalovirus, which was later discovered in his heart and may have played a role. Additionally, he received an experimental antibody treatment that unexpectedly triggered a severe gastrointestinal reaction.
Two individuals living with kidney disease, previously deemed unsuitable for traditional transplant eligibility, received genetically modified pig kidneys from a herd of donor pigs cultivated by the innovative biotechnology company eGenesis. Using CRISPR technology, the company achieved a remarkable 69-edition gene modification, successfully eliminating certain pig genes, incorporating human counterparts, and significantly reducing the risk of dormant viruses reactivating and causing harm to the individual receiving the organ transplant.
The procedures unfolded with apparent smoothness. Even though the primary patient’s kidney function was determined to be normal, he still didn’t want to undergo dialysis. Despite having received a new lease on life two months prior, he struggled with underlying health concerns that ultimately overshadowed the success of the transplant. The hospital’s investigation found no conclusive link between the organ donation and his eventual passing, suggesting other factors contributed to his demise.
A complex medical case required a kidney removal after 47 days due to “unique difficulties” arising from her recent mechanical heart pump implant, making the transplant procedure particularly challenging. While there were no signs of rejection, the kidney’s function started to decline due to the heart’s inability to pump blood at a sufficient pressure.
Recently, scientists made headlines by introducing the latest breakthrough: transplanting a genetically engineered pig’s liver into a 71-year-old man diagnosed with liver cancer in May. Despite confidentiality constraints surrounding the procedure, the employee reported that the individual in question had made significant progress more than two weeks post-surgery, with the workforce commenting that they were “doing very well”.
While most studies in this field have had limited duration, the fact that only two instances recorded a failed transplant, with one instance attributed to external factors, is an encouraging indication. Physicians have traditionally been limited to conducting experiments on patients with already compromised chances of survival for the sake of moral principles.
While acknowledging the potential of xenotransplantation, it is crucial to consider whether this approach can truly provide a sustainable solution for patients in the long term. While there are concerns about xenotransplantation’s potential risks, one pressing issue is the possibility of interspecies pathogen transmission, which could lead to unforeseen consequences.
Researchers are exploring the possibility of cultivating human organs within pigs as a potential alternative to traditional organ transplantation from pigs into humans. In late September, researchers successfully transplanted human stem cells into pig embryos, which subsequently developed into primitive kidney structures.
While this method still has a significant gap before it can be tested on humans, xenotransplantation appears to be a highly promising approach for reducing transplant wait times in the meantime. As initial results show encouraging signs, it appears unlikely that we’ll be shut out of a future where custom-made organs can be grown with ease.
