Raising the World's Cleanest Pigs for Human Kidney and Heart Transplants

Innovative Pig Farm May Revolutionize Organ Transplantation

In Blacksburg, Virginia, a unique pig farm might hold the key to overcoming the organ transplantation crisis. This specialized facility raises genetically modified pigs whose organs could potentially save human lives. Unlike typical pig barns, this farm operates behind strict biosecurity measures to ensure that visitors and staff do not introduce contaminants. According to David Ayares of Revivicor Inc., these pigs are meticulously cloned with specific genetic modifications to make their organs more compatible with human bodies.

Just a few miles away, in Christiansburg, Virginia, another state-of-the-art facility is preparing to conduct formal studies on animal-to-human transplants. This high-tech building, more akin to a pharmaceutical plant, is dedicated to raising pigs in an environment nearly free of pathogens. Here, only select employees are allowed in, and they must adhere to stringent decontamination protocols.

Creating Pigs for Organ Transplantation

The goal of these experiments is to address the critical shortage of human organs for transplantation. Thousands of Americans await transplants each year, with a significant number not surviving due to the scarcity of suitable organs. Companies like Revivicor and Makana Therapeutics are genetically engineering pigs to produce organs that closely resemble human ones. Four "compassionate use" transplants have already been performed in the U.S., although the patients didn't survive long-term. These initial cases provided crucial insights for future trials.

The Food and Drug Administration (FDA) is currently reviewing results from these initial experiments, including human cadaver studies and pig organ trials in baboons. These engineered pigs, tailored to the recipient’s size and free from the wear and tear typical in human-donated organs, show promising signs. Surgeons retrieving organs from these pigs often remark on their exceptional quality.

The Genetic Engineering Process

The process begins with gene editing in pig skin cells to eliminate immune-triggering genes and to introduce human ones. One significant milestone was deleting a sugar-producing gene named alpha-gal, which the human immune system would typically attack. Over the years, scientists have managed to perform multiple gene edits, reducing the risk of rejection and blood clots, and controlling organ size.

Revivicor clones pigs using a method similar to how Dolly the sheep was created. Weekly shipments from slaughterhouses provide the eggs needed for this process. Through meticulous lab work, researchers replace the pig's DNA with the desired genetic modifications, then use mild electric shocks to activate embryo growth. These embryos are then implanted into sows at the research farm.

Luxury Accommodations for Special Pigs

The pigs are given exceptional care in their secure, highly sanitized environment. Young piglets are socialized with music and toys, while older pigs enjoy spacious, air-conditioned pens. The farm, home to around 300 pigs, remains undisclosed for security reasons. Farm staff are dedicated to ensuring the pigs have a good quality of life, acknowledging the significant role these animals play in medical research.

A more restricted section of the facility houses pigs involved in critical experiments, including human trials and FDA-required studies. In Christiansburg, United Therapeutics operates a cutting-edge, pathogen-free facility poised to produce around 125 pig organs annually, enough to supply clinical trials. This facility provides a glimpse into the future of xenotransplantation, with potential expansions on the horizon to meet growing needs.

The Future of Xenotransplantation

While it will take years to determine the feasibility and safety of these animal-to-human transplants, early results show promise. If successful, large-scale production facilities could eventually supply up to 2,000 organs a year across the U.S. Researchers are optimistic, believing the next few years will yield groundbreaking advancements in the field.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group.