Improving the compatibility of pig organs for transplantation

Improving the compatibility of pig organs for transplantation

Subject :Science and tech

Section: Biotechnology

Context:

The design and successful transplantation of kidney grafts from genetically modified pigs into non­-human primates has been described in a recent study published in ‘Nature’ magazine.

What is Xenotransplantation?

• Xenotransplantation, or transplanting organs across different species, was first tried in humans in the 1980s.
• The experiment was abandoned after the famous case of the American Baby Fae who was born with a congenital heart defect and received a baboon heart in 1984.
• However, pig heart valves have been used for replacing damaged valves in humans for over 50 years now.
• Nowadays, harvesting organs from genetically engineered pigs is seen as a viable alternative to meet organs shortage.

How the pigs are genetically engineered?

• The donor pig underwent 10 genetic modifications, by which the genes responsible for the rapid rejection of foreign organs by the human body were inactivated or knocked out.
• Four pig genes were removed, and six human genes were added.
• “GalSafe” pigs, or pigs that had undergone editing to knock out a gene that codes for Alpha-gal (a sugar molecule) were used.
• Alpha-gal can elicit a devastating immune response in humans.
• GalSafe pigs have been well studied, and are approved by the US Food and Drug Administration (FDA) for use in pharmacology.

Why pursue xenotransplantation?

• Modern scientific supporters of xenotransplantation argue that the potential benefits to society outweigh the risks, making pursuing xenotransplantation the moral choice.
• None of the major religions object to the use of genetically modified pig organs for life-saving transplantation.
• A crucial case in India
• Harvesting organs from genetically engineered pigs is seen as a viable alternative to meet organs shortage.
• According to the health ministry, around 0.18 million people in India are estimated to suffer from renal failure every year, but only about 6,000 renal transplants are carried out in the country.
• About 25,000-30,000 liver transplants are needed annually in India but only about 1,500 are being performed.
• In the case of the heart, 50,000 people suffer from heart failure and are in need of a heart transplant.
• Yet, only 10-15 heart transplants are carried out in India each year.

Issues with Xenotransplantation

Besides scientific challenges, there are several ethical challenges to overcome:

• Animal rights: Many, including animal rights groups, strongly oppose killing animals to harvest their organs for human use.
• Decreased life expectancy: In the 1960s, many organs came from the chimpanzees, and were transferred into people that were deathly ill, and in turn, did not live much longer afterwards.
• Religious violations: Certain animals such as pork are strictly forbidden in Islam and many other religions.
• Informed consent: Autonomy and informed consent are important when considering the future uses of xenotransplantation.
• Threats of zoonosis: The safety of public health is a factor to be considered. We are already battling the biggest zoonotic disease threat.