A few days ago, from the midst of the daily gloom of COVID-19, came uplifting news of a pathbreaking surgical procedure in a New York hospital. A pig’s heart was successfully transplanted into a 57-year-old man dying of heart failure. The ‘xenotransplant’, as interspecies transplants are called, was a reminder of the endless possibilities to treat otherwise untreatable diseases.
Transplantation to replace failing organs is one of the spectacular achievements of medicine in the last century. The number of transplants has increased, the list of organs transplanted has grown and outcomes have got better. But the field is also a victim of its own success as the numbers of those needing transplants now far outnumbers the availability of human organs. Both living and dead humans are being sourced as donors but because of scientific, ethical and social challenges, the number of human donors remains restricted. The desperation for organs also creates a fertile ground to lure the vulnerable to sell their organs as we witnessed in the recent kidney scandal in Assam.
Given organ shortage, it is intuitive that scientists would turn to animals. It also overcomes another hurdle in human to human transplant; one does not have to seek consent from an animal which can be sacrificed for the organ. Of course not all agree with such a narrow utilitarian approach.
The use of animal organs to replace diseased human ones is a very old idea. Some of the earliest blood transfusions were from animals. Early kidney and liver transplants were attempted from baboons and chimpanzees as these primates were considered closest to humans. In the early 1960s, a surgeon called Reemtsma in New Orleans performed 13 chimpanzee to human kidney transplants. One of the recipients, a schoolteacher, went back to work and lived for 90 days. However, most of these transplants failed and were gradually given up.
The interest in pigs as a source of human organs is recent. There are several reasons why scientists have now zoomed in on these otherwise shunned creatures as a source. One interesting reason is that in the western world, it is socially more acceptable to breed pigs for this purpose. From a scientific viewpoint, pigs are genetically modifiable to reduce the chances of rejection by the human body. There are concerns about the transmission of pig viruses through the transplant but this barrier has also been partly overcome by bio protection and genetic manipulation. But COVID-19 will regnite this debate.
In what sounds somewhat dystopian, there are now companies breeding genetically modified pigs in special farms for the express purpose of transplantation. One such U.S.-based company Revivicor supplied the pig heart for the New York transplant.
Will this transplant boost xenotransplantation? Will this mean the end of organ shortage? Even the most optimistic scientists will agree that these are still open questions but the developed world is inching in this direction. It is a matter of time before more xenotransplants are attempted. When this happens, there will be the question of whether the organ will function in the long term. And, whether it will transmit hitherto unknown diseases to humans. A dying individual offered a xenotransplant as the only life-saving option may not care for such questions.
The animal rights movement is not impressed. PETA has decried the pig heart transplant. It said: “Animals aren’t tool-sheds to be raided but complex, intelligent beings. It would be better for them and healthier for humans to leave them alone and seek cures using modern science.” Coming from meat-eating countries, this sounds somewhat paradoxical. The easy public acceptance of the pig compared to other animals as a source says something about our double standards.
There was a curious fallout of the New York case in India. The local media suddenly remembered the bizarre story of a heart transplant attempted by a surgeon called Baruah in the 1990s. Some went on to describe this as the world’s first attempt. Baruah, working out of his Guwahati clinic, had transplanted the lung and heart of a pig into 32-year-old Purno Saikia. It was clearly a premature experiment using an unsuspecting poor Indian as a guinea pig. It ended in disaster for the patient and Baruah who was struck off his medical degree.
Though somewhat shaken by COVID-19, humanity’s desire to prolong life at all costs is a given. An increasingly common cause of death and suffering is end stage failure of critical organs (heart and liver). And since new organs replace failing ones successfully, we will continue to widen the net for sourcing them. But in our quest towards immortality, recent events show that in good and bad ways, our lives depend not only on other humans but also on other species cohabiting the planet; all creatures big and small.
Dr. Sanjay Nagral is a surgeon and writer basedin Mumbai