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| This handout photo released by the University of Maryland School of Medicine shows surgeons performing the transplant of a heart from a genetically modified pig to a patient in Baltimore, Maryland Jan.7. AFP-Yonhap |
Cross-species transplant viable solution to organ donation shortage
By Lee Hyo-jin
A recent series of successful pig-to-human organ transplants performed by U.S. surgeons have set a major milestone in the history of medicine, bringing Koreans' attention to when the country might be able to see its first xenotransplantation surgery.
On Jan. 7, surgeons at the University of Maryland School of Medicine conducted the transplant of a genetically modified pig heart into the body of a 57-year-old male patient with heart failure, marking the first such surgery of its kind.
It was followed by another watershed moment, when surgeons at the University of Alabama Birmingham successfully transplanted a genetically modified pig kidney into a 57-year-old man who was brain-dead, Jan. 20.
Xenotransplantation ― transplants of live organs, tissues or cells to humans from non-human species ― is also a growing field in Korea, as it would offer life-saving options for many patients suffering from chronic organ failure.
Park Chung-gyu, a professor of microbiology and immunology at Seoul National University College of Medicine, says local researchers have been highly encouraged by these success stories of genetically modified organ transplants in the U.S.
In a recent phone interview with The Korea Times, the former head of the xenotransplantation research center in Korea said, "Previously, there have been some successful moments in testing pig hearts on non-human primates, but this was the first case where an animal heart replaced a human heart and was not rejected by the patient's immune system."
But Park added that it may be too early to tell whether the surgery is a success, saying, "The patient may need to be monitored for a few more weeks or months to see how the new organ functions."
In Korea, a team of researchers led by Park in cooperation with local biotech firm GenNBio, are working on the transplantation of pancreatic islets from germ-free pigs to patients suffering from Type 1 diabetes, an autoimmune disease in which the pancreas fails to produce the hormone, insulin.
The pancreatic islets, also known as islets of Langerhans, are patches of endocrine tissue located within the pancreas that contain insulin-secreting B cells.
Park explained that unlike in xenotransplantation procedures of other organs, such as hearts or kidneys, the inter-species transplantation of pancreatic islets does not require genetic modification, alleviating concerns over the risks of rejection.
"We have seen meaningful results through testing in non-human primates, based on which, we submitted an application to start a phase 1 clinical trial at the Ministry of Food and Drug Safety in August of last year. We hope to win approval within this year," said Park.
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| Pigs in a germ-free cage at Seoul National University's College of Medicine / Korea Times file |
If the project succeeds, patients with Type 1 diabetes may be offered an option other than insulin injection. Further development of inter-species transplantation could help to tackle the shortage of donated organs in Korea.
While transplantation is the only therapeutic option left for many patients with chronic organ failure, the number of donated organs and tissues falls far short of demand, according to data from the Ministry of Health and Welfare.
In 2020, 35,852 patients were on the waiting list, up 9 percent compared to the previous year.
At the same time, fewer people are choosing to register for organ donation, with 67,160 people having registered to donate their organs in 2020, a 25-percent decline from 90,350 in the previous year.
Due to the shortage of donors, an increasing number of patients are dying while waiting for organ transplant surgery: 1,762 patients died in 2017, 1,894 in 2018, 2,142 in 2019 and 2,194 in 2020.
Lack of guidelines and ethical dilemmas
However, it remains to be seen whether researchers will be able to win authorization for clinical trials this year, due to the absence of clear guidelines for verifying the safety and efficacy of these operations.
"As this is the first such approval process in the country, the authorities seem to be thoroughly reviewing our data, and we have continued to submit additional data at their request," said Park.
The drug affairs ministry is conducting research ― expected to be completed by May ― to set up approval guidelines for xenotransplantation clinical trials. Based on this research, it will come up with the relevant guidelines.
In addition, even if the trials are approved, long-standing ethical concerns surrounding xenotransplantation are certain to stir debate.
Some international animal rights organizations, such as People for the Ethical Treatment of Animals (PETA), have already voiced strong protests over animal-to-human transplants conducted in the U.S.
On the grounds of animal abuse, as well as based on potential risks of spreading diseases, they called the operations "unethical, dangerous, and a tremendous waste of resources that could be used to fund research that might actually help humans."
