Bioethics News

Human-Pig Chimeras: The Potential and Concerns Of Hybrid Human-Animal Organs

One of the great advances in modern medicine has been the success of organ transplantation. Whilst complications still arise from its use, the refinement of drugs designed to reduce organ rejection alongside other improvements, mean that the procedure is often lifesaving.

As is frequently the case however, there is a caveat to this “wonder-cure”, namely, that far more people require organs than there are organs available. This global shortage has given rise to a host of complex ethical challenges. Several of these issues have already been explored here, including the implementation of ‘opt-in’ organ donation systems and the appropriateness of receiving organs on the basis of ability to pay1, 2, 3.

The development of chimeric human-pig embryos announced in the journal Cell last week may therefore be hailed as the much-needed answer to this problem of organ shortages. With over 120,000 people on the national transplant list in the US alone and 22 people on that list dying each day, any opportunity to increase the numbers of transplantable organs has an obvious appeal4. However, this development is far from a perfect solution.

Chimeric embryos are early life forms that are composed from 2 or more different sets of genetic material. In this case therefore, one set of genetic material is from a pig and the second from a human. These chimeras were initially made in the laboratory, before being transplanted into surrogate sows. In the study, only a fraction of the total embryos transplanted (just over 10%) showed successful development, surviving for 3-4 weeks5.

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.