Scientists Use Pigs to Try to Beat Cystic Fibrosis

WASHINGTON (Reuters) - U.S. scientists have created pigs that appear to develop cystic fibrosis just as people do, a step they hope will accelerate efforts to tackle the disease.

Writing in the journal Science on Thursday, scientists at the University of Iowa and the University of Missouri said they created genetically engineered piglets with the same mutation that causes cystic fibrosis in people.

Studying how the disease unfolds in these pigs may provide insights into cystic fibrosis that thus far have eluded scientists and could point toward new treatments or maybe even a cure, said Dr. Michael Welsh of the University of Iowa.

People get CF when they inherit two mutated copies of a gene called CFTR, which was pinpointed as the cause in 1989. The disease causes mucus to accumulate and clog some of the organs in the body, especially the lungs and pancreas.

The Cystic Fibrosis Foundation, which helped fund the study, said about 70,000 people worldwide, including 30,000 people in the United States, have CF. People with the disease can expect to live to about age 37.

Scientists create animal "models" of a disease in order to perform experiments that would not be possible with people. Mice with the genetic abnormality that causes cystic fibrosis have been developed, but the disease presents itself very differently in these rodents than in people.

"Unfortunately, the mice leave something to be desired," Welsh, who helped lead the study, said in a telephone interview.

"They don't get the pancreatic disease like people with CF get. They don't get the lung disease like people with CF get. They don't get the intestinal disease like people with CF get. There's been many questions that can't be answered," he added.

"The onset of these problems is difficult to track down in humans because sometimes they happen before birth or sometimes they happen silently," added Christopher Penland of the foundation.

This is the latest example of pigs used for human medical needs. For example, cardiac patients can get pig heart valves.

The scientists developed pigs with cystic fibrosis because their lungs have many characteristics of human lungs.

"Right now, if you want to do experiments to find treatments or therapies for the lung disease that is fatal for people with CF, you would have to experiment on kids that have CF," Randy Prather of the University of Missouri added.

The disease in pigs closely mimicked the initial stages of the disease seen in people. The scientists are waiting for them to develop lung disease typical of CF "so we can start experimenting in ways that have never been possible," Prather said in a statement.