Chinese scientists are now desperately seeking government approval to launch a clinical trial for xenotransplantation. The goal is to have genetically modified pig organs transplanted into humans. This could happen as early as 2019.

pig organ transplant

Credit: Pixabay.

Every country on Earth is in short supply of organs for transplants with some patients staying on waiting lists for years, some over a decade. Suffice to say most die from health complications before they get a chance to receive a heart, lung or kidney. This situation could go on forever unless we find a way to literally grow transplant organs.

An unbeaten path

One promising approach involves genetically modifying pigs whose organs can then be transplanted to a human patient. This procedure is referred to as xenotransplantation. Out of all mammals, a pig’s organs are the most compatible with those of humans in terms of size and metabolism.

To demonstrate how such a procedure might work, scientists working with the National Heart, Lung and Blood Institute, USA, grafted a pig’s heart to a baboon’s last year. The researchers suppressed the alpha 1-3 galactosyltransferase gene which produces an epitope that is easily recognized as foreign. This way, the baboon’s immune system doesn’t attack the pig heart although immunosuppressants still had to be taken.  Amazingly, the longest a pig heart kept beating was 945 days or nearly three years.

The leader in this field, however, is China. According to the South China Morning Post, about 1,000 cloned pigs are made inside dedicate clone farms around China.

Also in China, no fewer than ten national institutes are closely collaborating for xenotransplantation project funded by the central government. Already, there is fantastic progress. For instance, 400 cornea transplants have been performed from pigs to humans with a stunning 95 percent success rate once the Chinese government gave the green light in 2015.

Now, the same scientific consortium is looking permission from the government to make the next big step: a clinical trial for organ xenotransplantation.

This could happen as early as two years from now, South China Morning Post reported, although there’s a good chance the deadline could be extended even further. It seems like the Chinese government is delaying giving the go. Corneas, which don’t contain blood vessels, are one thing but an organ which can be mind-wrecking complex is a whole different ballgame.

“We have patients dying from organ failure and their desperate relatives pleading for them to have the chance to live,” said Zhao Zijian, director of the Metabolic Disease Research Centre at Nanjing Medical University in Jiangsu.

“But when we turn to the authorities in charge of approving the clinical trials, all we get is silence. We understand it must be very hard for the government to make a decision, but it’s time we got an answer,” he added.

Zhao admitted, however, that genetically modified pig organs are barely a 50 percent match for human organs. According to the Chinese leading scientist, it’s quite possible that a pig organ transplanted tomorrow inside a human’s body won’t get rejected. The big risk though is in the long term such as inflammation as a result of the immune system attacking the transplanted heart or lung.

Even in such an experimental stage, however, for many patients, such a procedure would be much welcomed. In the end, there can’t be progress absent clinical trials.

“Someone has to take the first step – whether it’s the US Food and Drug Administration or the China Food and Drug Administration,” he said.

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