Docs Pull Off 2nd Pig Kidney Transplant

A self-described science nerd is the latest American to get an experimental pig kidney transplant, at a crucial point in the quest to prove if animal organs really might save human lives. The 54-year-old New Hampshire man is faring well after his June 14 operation, doctors at Massachusetts General Hospital announced Monday. "I really wanted to contribute to the science of it," Bill Stewart, an athletic trainer from Dover, New Hampshire, told the AP. That's not the only milestone the Mass General team is marking: A pig kidney has kept another New Hampshire man, Tim Andrews, off dialysis for a record seven months and counting. Until now, the longest that a gene-edited pig organ transplant was known to last was 130 days.

Based on lessons from the New Hampshire men and a handful of other one-off attempts, the Food and Drug Administration approved pig producer eGenesis to begin a rigorous study of kidney xenotransplants. "Right now we have a bottleneck" in finding enough human organs, said Mass General kidney specialist Dr. Leonardo Riella, who will help lead the new trial. Initial experiments, two hearts and two kidneys, were short-lived and included very ill patients. Chinese researchers also recently announced a kidney xenotransplant but released little information. Then an Alabama woman whose pig kidney lasted 130 days before rejection prompted its removal, sending her back to dialysis, helped researchers shift to not-as-sick patients.

After two years in dialysis, Stewart heard about Mass General's most recent xenotransplant recipient—Andrews—and applied. "I've always been a little bit of a science nerd," Stewart said. Conscious of how new these experiments are, he sought out Andrews for advice and ultimately decided, "worst case scenario, they can always take it out." Thrilled to no longer have his time and energy sapped by dialysis, Stewart said he's easing back into work and visited his old dialysis clinic to "let everyone know I'm doing all right and maybe kind of give some people some hope." Riella said it's too early to predict how long pig kidneys might last—but it would be useful even if initially they can buy people time off dialysis until they get a matching human organ. "A year, hopefully longer than that—that's already a huge advantage," he said.