xeno transplantation

 The Inquirer has an article about China growing organs in pigs.

you can go and read the entire article, which sounds more like propaganda than science and if you look beyond the headlines, it is a very preliminary experiment.

Chinese scientists made a world record for growing the first-ever humanized kidneys in pigs. In other words, they have figured out how to create organs in pigs, potentially helping those who need transplants.

We could use this method to produce vital body parts instead of waiting for donors. Still, the project requires further research and development for real-life applications.The experts admitted their experiment has several flaws, but it may pave the way for better healthcare.

This is a very preliminary experiment, and the article goes into the details.

But should you worry?

yes. Because an organ grown in a pig will pick up pig viruses, and the person getting the organ will be exposed to these viruses. And it will increase the chance of the viruses mutating to a fully human version that could kill people.

Am I being paranoid? Well, read this article in the New England journal of Medicine

except of course it is behind a paywall. Sigh

a similar article on the Wiley library site from 2018: and they deny that any of these viruses could affect humans so no problem

Swine herpesviruses including porcine cytomegalovirus (PCMV) and porcine lymphotropic herpesvirus (PLHV) are largely species-specific and do not, generally, infect human cells. Human cellular receptors exist for porcine endogenous retrovirus (PERV), which infects certain human-derived cell lines in vitro. PERV-inactivated pigs have been produced recently. Human infection due to PERV has not been described. A screening paradigm can be applied to exclude potential human pathogens from “designated pathogen free” breeding colonies.

The available data suggest that risks of xenotransplant-associated recipient infection are manageable and that clinical trials can be performed safely. Possible infectious risks of xenotransplantation to the community at large are undefined but merit consideration.

this article is from a vet journal

Porcine endogenous retroviruses (PERVs) are integrated in the genome of all pigs, and some of them are able to infect human cells. Therefore, PERVs pose a risk for xenotransplantation, the transplantation of pig cells, tissues, or organ to humans in order to alleviate the shortage of human donor organs. Up to 2021, a huge body of knowledge about PERVs has been accumulated regarding their biology, including replication, recombination, origin, host range, and immunosuppressive properties. Until now, no PERV transmission has been observed in clinical trials transplanting pig islet cells into diabetic humans, in preclinical trials transplanting pig cells and organs into nonhuman primates with remarkable long survival times of the transplant, and in infection experiments with several animal species. Nevertheless, in order to prevent virus transmission to the recipient, numerous strategies have been developed, including selection of PERV-C-free animals, RNA interference, antiviral drugs, vaccination, and genome editing. Furthermore, at present there are no more experimental approaches to evaluate the full risk until we move to the clinic.

MIT Tech review notes that a pig heart recipient did get infected:The gene-edited pig heart given to a dying patient was infected with a pig virus The first transplant of a genetically-modified pig heart into a human may have ended prematurely because of a well-known—and avoidable—risk.

The presence of the pig virus and the desperate efforts to defeat it were described by Griffith during a webinar streamed online by the American Society of Transplantation on April 20. The issue is now a subject of wide discussion among specialists, who think the infection was a potential contributor to Bennett’s death and a possible reason why the heart did not last longer.

but they deny it spread to the patient (it destroyed the heart but not the patient)

the real problem is mutation of a virus.

PBS FrontlineIt is known that infectious viruses, including the Epstein-Barr virus and cytomegalovirus, can be transmitted during allotransplants -- transplants involving individuals in the same species. Therefore, many worry that animal-to-human cell, tissue or organ transplants may make it easier for viruses to cross the species barrier.

and they list a few.

but maybe the worst ethical experiment is this report: They put pig organs into "brain dead" patients.

Ah but were they brain dead, or merely in a deep coma?