Why in News:

• The first person to receive a heart transplant from a pig has died, two months after the groundbreaking experiment.
• Prior attempts at such transplants — or xenotransplantation — have failed largely because patients’ bodies rapidly rejected the animal organ. This time, surgeons used a heart from a gene-edited pig.
• Scientists had modified the animal to remove pig genes that trigger the hyper-fast rejection and add human genes to help the body accept the organ.

What is Xenotransplantation

• Xenotransplantation is any procedure that involves the transplantation, implantation or infusion into a human recipient of either (a) live cells, tissues, or organs from a nonhuman animal source, or (b) human body fluids, cells, tissues or organs that have had ex vivo contact with live nonhuman animal cells, tissues or organs. The development of xenotransplantation is, in part, driven by the fact that the demand for human organs for clinical transplantation far exceeds the supply.

 Significance

• This breakthrough may bring us one step closer to resolving the worldwide organ scarcity.
• Xenotransplantation, if found compatible in the long run, could help provide an alternative supply of organs to those with life-threatening diseases.
• It can eliminate illegal organ trafficking.
• In India, between 25,000 and 30,000 liver transplants are required each year. However, just approximately 1,500 people receive them.
• According to the health ministry, over 0.18 million individuals in India suffer from renal failure each year, but only about 6,000 kidney transplants are performed in the nation..
• In the case of the heart, 50,000 patients have heart failure and require a heart transplant.

Despite this, barely 10-15 heart transplants are performed in India each year.

• Pigs have an edge over primates when it comes to organ harvesting since they are easy to grow and reach mature human size in six months.

• Pig heart valves are frequently transplanted into humans, and some diabetic patients have received pancreatic cells from pigs.
• Pigs have long been used in human medicine, including pig skin grafts and implantation of pig heart valves.

Why pigs?

• The pig’s anatomical and physiological parameters are similar to that of humans, and the breeding of pigs in farms is widespread and cost-effective. Also, many varieties of pig breeds are farmed, which provides an opportunity for the size of the harvested organs to be matched with the specific needs of the human recipient.
• Also, the pig’s heart is similar to the human heart.

How is a pig heart made compatible for a human?

• The molecular incompatibility between pigs and humans can trigger several immune complications after the transplant, which might lead to rejection of the xenograft.
• To preempt that situation, genetic engineering is used to tweak the genome of the pig so as to ‘disguise’ it, so that the immune system of the human recipient fails to recognise it, and the reactions that lead to xenograft rejection are not triggered.

Issues associated with xenotransplantation

• Animal rights: Many people, especially animal rights organisations, are highly opposed to murdering animals in order to harvest their organs for human use.
• Reduced life expectancy: In the 1960s, many organs were harvested from chimps and transplanted into terminally ill individuals, who did not live much longer as a result.
• Religious violations: In Islam and many other religions, some animals, such as pork, are absolutely banned.
• Informed consent: When considering the future uses of xenotransplantation, autonomy and informed consent are critical.
• Zoonosis dangers: The safety of public health is an important element to consider. We are already dealing with the most serious zoonotic disease danger.

Related laws

• In India, we have the Human Organs Transplant Act 1994, but it doesn’t mention animal transplants even as a possibility in extreme emergencies.

Way Forward

• Instead of outright prohibiting xenotransplantation, the government should examine the possibilities and conduct research and trials before legalising xenotransplantation in India.
• India should adopt the Spanish concept of “presumed consent,” in which everyone is deemed a donor after death unless they opt out during their lifetime.

References:

1. https://indianexpress.com/article/explained/everyday-explainers/what-is-xenotransplantation-7814612/
2. https://www.thehindu.com/sci-tech/science/us-man-who-got-first-pig-heart-transplant-dies-two-months-after-surgery/article65208441.ece