Pancreas cells from pigs might someday reverse diabetes

One day, type 1 diabetes patients may be able to get pancreas cells from pigs that will permanently reverse their disease.

That's the promise of a study released Thursday by scientists at Children's Hospital of Pittsburgh of the University of Pittsburgh Medical Center and in Virginia and the Netherlands.

Writing in the December issue of the American Journal of Transplantation, a research team headed by Dr. Massimo Trucco of Children's reported that genetically engineered pancreas cells from pigs were still producing insulin and preventing diabetes in a monkey more than a year after transplant.

If further monkey trials show similar success, the scientists may be ready to conduct human trials with pig cells in two to three years, said Dr. David Ayares, CEO and chief scientific officer of Revivicor Inc., the Blacksburg, Va., company that grows the special pigs.

Type 1 diabetes is an inherited condition in which patients don't produce insulin, which is needed to convert sugar into energy for cells. As a result, they usually face a lifetime of insulin shots, and even with that therapy, are vulnerable to blindness, heart disease, kidney problems and amputations.

One solution to type 1 diabetes is pancreas transplants, but as with other organs, there is a severe shortage of donated pancreases in the United States. Last year, more than 3,700 people were waiting for pancreas transplants, but only about 435 were performed, according to the United Network for Organ Sharing.

Even fewer pancreases are available for so-called islet cell transplants, in which the cells that produce insulin are extracted and infused into patients' livers, where they establish "mini-pancreases" to produce insulin.

For many diabetes patients who get human islet cell transplants today, the cells only last from several months to a few years, and the patients then either have to get more transplanted cells or go back to injected insulin, Ayares said.

That's where pig cells may be a solution, he said, and it's why the results of the new study are so exciting.

Not only are pigs similar to humans biologically, he said, but they can be grown to adulthood in about six months and don't face the same ethical and medical restrictions for transplant use as monkeys and other primates do.

Revivicor is a spinoff from the Scottish company that created Dolly the sheep, the first mammal cloned from cells that make up the body.

In the new study, Revivicor grew pigs that were genetically engineered to include a human gene that makes a protein called CD46, which helps suppress the body's immune attack on transplanted cells.

Examination of the monkeys' organs showed that the protein had helped protect the pig cells from assault by the monkeys' immune systems, Ayares said.