For years and years, humankind has been captivated by the concept of transferring organs from animals to humans, as proven by a slew of mythical characters ranging from Hindu god Ganesh to Greek hero Daedelus. The first scientific mention of Xenotransplantation occurred in 1905 in France, when rabbit kidney slices were implanted in a youngster suffering from chronic renal insufficiency.

This procedure of Xenotransplantation, that is, transferring organs across other species might give an alternate and supplementary supply of organs for patients with life-threatening conditions if it is shown to be compatible in the long term. According to a Columbia University researcher’s report on Xenotransplantation: A Historical Perspective, the early results were remarkable. Two further transplantations were reported in 1906, one from a pig and the other from a goat, but neither graft functioned.

Sandeep Mahajan, a nephrologist at the All-India Institute of Medical Sciences (AIIMS), told The Print that previous occurrences used organs from nonhuman primates such as chimps and baboons.

Pig Kidney Transplant: History

The first cornea transplant was performed on a pig in 1838, 65 years before the first human-sourced organ was transplanted in 1905. By the 1960s, surgeons started replacing human kidneys with chimp or baboon organs. 

None of these experimental approaches, however, proved to be long-term successful. Despite the similarity of nonhuman monkey and pig organs to human organs, earlier transplant studies have routinely resulted in prompt organ rejection by the human immune system.

Current Scenario of Pig Kidney Transplant:

Reuters, New York, Oct 19 – 

A pig kidney has been transplanted into a person for the very first time without the recipient’s immune system rejecting it right away. This potentially momentous breakthrough might someday help ease a critical scarcity of human organs for transplant.

A pig whose genes had been altered such that its tissues no longer carried a chemical known to induce nearly instantaneous rejection was used in the surgery at NYU Langone Health in New York City.

According to Reuters, the receiver was a brain-dead woman with evidence of renal failure whose family agreed to the experiment before being taken off life support. The replacement kidney was linked to her blood veins and kept outside her body for three days, allowing researchers access to it.

The function of the transplanted kidney “appeared very typical,” according to the study’s lead author, transplant physician Dr. Robert Montgomery. The kidney began operating and generating substantial volumes of urine within minutes of being linked to the person’s blood veins, who presided with the surgical team. 

He also stated that the creatinine level in the blood, which is cleansed by the kidney, went from 1.9 to 0.8. That indicated that the kidney was working correctly. He is a professor and head of NYU Langone Health’s Department of Surgery and the Director of its Transplant unit. After the transplant, the recipient’s elevated creatinine level – a sign of impaired kidney function – reverted to normal, according to Montgomery.

How can a Pig’s Kidney be used to transplant in Humans?

Pigs have been the centre of current research to alleviate organ scarcity. However, there are several challenges: A substance found in pig cells that is alien to the human body causes organ rejection right away. 

This experiment used a kidney from a genetically modified animal designed to remove the sugar and escape an immune system assault. To study the pig kidney for two days, surgeons linked it to a pair of significant blood veins outside the body of a dead recipient. The kidney completed its job — filtering trash and producing urine — and did not cause rejection. Dr. Robert Montgomery stated, “It functioned perfectly and didn’t have the quick rejection that we were concerned about.”

Why a Pig and no other animals?

Although monkey organs are more compatible with humans, pigs are simpler to manipulate genetically. They also have larger litters, develop faster, and are less prone to illness transmission. Their organs are very comparable in size to ours.

Did they transplant the pig kidney inside the human body?

No. The kidney was connected to blood veins outside the abdomen, in the upper thigh. For observation, it was shielded with a protective shield. During the 54-hour research period, the kidney remained pink and well-perfused, according to Dr. Montgomery. 

Biopsies obtained every 12 hours and examined under a microscope revealed no signs of rejection or indications of toxic antibodies attacking the kidney from human blood.

Why is this work so important?

“With the ever-increasing frequency of organ failure, the conventional paradigm that someone needs to die for someone to live will never be able to keep up.” The demand for organs will always outnumber the available supply. If human organs are the fossil fuels of the organ supply, pig organs are the wind and sun — renewable and limitless,” Dr. Montgomery remarked.

He said that further research over a more extended period is needed to comprehend the compatibility in the long term completely. However, he believes that a pig-to-living human kidney transplant would be possible within a few years. He goes on to say that in roughly ten years, we’ll be able to transplant pigs’ hearts, lungs, and livers.

How will the Pig Kidney Transplant revolutionize Kidney treatment?

Nearly 107,000 patients in the United States are awaiting organ transplants, with more than 90,000 of them waiting for a kidney. The usual wait period for a kidney transplant is three to five years. 

Researchers have been working on the potential of utilizing animal organs for transplants for decades. The question which has been a hurdle is how to avoid quick rejection by the human body.

According to Montgomery, who received a heart transplant himself, the NYU kidney transplant experiment should pave the way for studies in patients with end-stage renal failure in the next year or two. Those trials might see if the method can be used as a temporary fix for severely unwell individuals until a human kidney becomes available.

In a statement, United Therapeutics CEO Martine Rothblatt stated, “This is a crucial step forward in achieving the promise of xenotransplantation, which will save thousands of lives each year in the not-too-distant future.” Tests on nonhuman primates and a human body experiment last month, according to experts, open the way for the first experimental pig kidney or heart transplants in living people in the coming years.