Think tank announces breakthrough in organ transplants

The state-run Rural Development Administration said Wednesday that it has produced a genetically engineered pig whose organs will cause less rejection when transplanted into humans.

The breakthrough is expected to open a new chapter in xenotransplantation, or the transplant of organs from one species to another.

“We`ve succeeded in producing the genetically modified pig ‘Somang-i,’ which will prevent acute vascular rejection of animal organs by the human body,” the agency said.

Pigs are frequently used in xenotransplantation as the structure of their organs is similar to that of humans. To prevent rejection of animal organs, researchers produced Somang-i by applying human genes to it.

When animal organs are transplanted to humans, they tend to show rejection in stages -- hyperacute, acute, cell-mediated and chronic -- leading to blood coagulation and thrombosis and resulting in death due to ischemia in the worst cases. This is because the immune system attacks animal organs by considering them attackers like viruses.

Hyperacute rejection occurs within a few minutes or hours after the transplant, acute rejection within several days, cell-mediated rejection within several months, and chronic rejection within several years.

Organs from the genetically modified pig produced by the think tank can significantly reduce acute vascular rejection by preventing blood coagulation.

Prior to Somang-i, the think tank produced in 2009 the country’s first genetically modified pig “Xeno” by removing genes causing hyperacute rejection in human. Last year, it developed another genetically engineered pig called “Mideum-i” that can prevent acute rejection.

Park Jin-gi, head of the Rural Development Administration`s animal bioengineering department, said, “If we crossbreed Somang-i with Xeno or Mideum-i, we can produce a multiple transgenic pig that can control two to three immune genes. In this regard, the latest breakthrough is very meaningful.”

In Korea, the number of patients needing organs grows 10-15 percent every year. They have difficulty finding the necessary organs due to lack of organ donors.

The think tank said, “1.58 million people worldwide will be on the waiting list for organ transplantation by 2015,” adding, “In advanced countries such as the U.S. and those in Europe, chimpanzees and monkeys that received pig organs survived for six months.”

imsun@donga.com