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August 26, 2022

TOKYO – The Department of Health, Labor and Welfare will begin developing new guidelines for “xenotransplantation” – transplants of animal organs and tissues into humans – in the next fiscal year.

As research progresses on creating organs for transplantation that limit rejection by the immune system using new technology for modifying the genetics of the donor animal, xenotransplantations are now being carried out abroad, although only on an experimental basis.

In light of these developments, the ministry aims to ensure the quality and safety of non-human organs to be transplanted into humans, with a view to eventually carrying out such transplants in the country.

It is hoped that non-human organ and tissue transplants from sources such as pigs will help solve an ongoing shortage of organs needed by people with chronic conditions.

However, transplant rejection, in which the transplanted organ is attacked by the immune system, presents a major challenge for xenotransplantation. It was also pointed out that unknown viruses can enter the cells of the organ to be transplanted.

The Ministry of Health will establish a research team within the Japanese Agency for Medical Research and Development to examine issues such as the quality of organs from animals, such as those from pigs, and the risks of infection. viral. The team will also study the latest technological trends and the likelihood of abnormalities in humans if genetically modified non-human organs and tissues are used for transplants.

Over a period of approximately three years, the team will compile a list of pointers for xenotransplantation that will include methods for testing for viruses and assessing the risk of transplant rejection, as well as husbandry requirements for animals to be use for xenotransplantation.

The ministry plans to include several tens of millions of yen for related expenses in its budget request for the next fiscal year.

In recent years, researchers have made progress in developing non-human organs with a low risk of transplant rejection using technologies such as genome editing, which allow them to make precise changes to targeted genes.

In the United States, doctors performed the world’s first xenotransplantation of a pig’s heart in a human in January this year, using a pig’s heart with 10 genetic modifications to limit transplant rejection. (The patient died approximately two months later.)

In Japan, the Ministry of Health developed guidelines in 2016 that pancreatic and other cell transplants from animals to humans were approved provided that thorough follow-up studies were conducted on the health of the cell recipients.

However, these guidelines were not developed with consideration for xenotransplantation of organs or tissues, and so far no such transplants have been performed in Japan.