Bioethics Blogs

Human-pig ‘chimeras’ may provide vital transplant organs, but they raise ethical dilemmas

Growing human organs in pigs mean they’re doing our dirty work for us.

Organ transplantation is one of modern medicine’s success stories, but it is hampered by a scarcity of donor organs. Figures for the UK published by the NHS Blood and Transport Service show that 429 patients died in 2014-2015 while awaiting an organ. What’s more, many of the 807 removed from the waiting list will have been removed because they became too ill to receive an organ, and are likely to have died as a result.

So while there is a strong ethical imperative to increase the supply of donor organs, many of the methods tried or proposed – presumed consent, allowing organs to be bought and sold, and using lower-grade organs such as those from donors with HIV – are themselves controversial. And even if we accept these approaches it’s unlikely they will be sufficient to meet the demand.

Gene editing techniques such as CRISPR could provide the answer. These techniques allow us to make precise changes in the DNA of living organisms with exciting prospects for treating disease – for example by modifying human DNA to remove genes that cause disease or insert genes associated with natural immunity to conditions such as HIV/AIDS. However, gene editing the DNA of animals could prove equally important for the medical treatment of humans.

Scientists are now working on a technique that would allow human organs to be grown inside pigs. The DNA within a pig embryo that enables it to grow a pancreas is deleted, and human stem cells are injected into the embryo.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.