Progress Reported in Producing Pigs With Organs for Transplantation

A Wisconsin biotech firm reported it has genetically engineered and cloned a litter of three piglets with organs that may resist rejection by the human immune system if transplanted into humans.

Infigen Inc. said the miniature pigs were genetically altered to knock out both the maternal and paternal copies of a gene that causes rapid rejection of pig organs by the human body.

"This is a major, major landmark contribution," said Dr. Hans Sollinger, head of the University of Wisconsin organ transplant program. "Xenotransplantation will not happen tomorrow, but at least this will give us a great experimental opportunity."

Infigen's miniature pigs are not the first swine to be born with both copies of the crucial gene eliminated but they are the first multiples. One minature pig was produced at the University of Missouri in November 2002.

Also, PPL Therapeutics of Edinburgh, Scotland, produced regular-size pigs with both copies of the genes knocked out at its U.S. facility last August.

Miniature pigs, which grow to about 180 pounds, are better suited than the much larger regular-size pigs for potential use in transplantation because their organs are closer to human size.

The first experiments that are expected to be conducted with the genetically modified pigs will be an effort to transplant organs into baboons. If these transplants work out, researchers said initial human trials could be three to five years away.

Other Sources: Infigen