A new experimental model is helping researchers better understand how cystic fibrosis (CF) causes lung disease in people with the condition. The findings, published in the journal Science Translational Medicine, could help improve treatments for lung disease, which causes most of the deaths and disability among people with CF.

The researchers used pigs with a CF-causing gene mutation to answer the question about which comes first in CF lungs—infection or inflammation.

“Using our model we are beginning to answer that question, and it looks like infection does precede inflammation,” said David Stoltz, MD, PhD, assistant professor of internal medicine at the University of Iowa (UI), assistant director of the Adult Cystic Fibrosis Center at UI Hospitals and Clinics, and lead study author. “The importance of that finding is that it could dictate what types of therapy we might use. Knowing that infection is first suggests that if we can prevent or fight infection, then that might delay or prevent the lung disease in people with CF.”

The findings would seem to support early and aggressive treatment of lung infections in children with CF, according to Stoltz.

The team used the pig model in the hope that it would more closely mimic the human disease than mouse models do. By studying the CF pigs through their first 6 months of life, the researchers found that these animals do develop lung disease typical of that seen in humans, including infection in the lungs, inflammation, and accumulation of mucus in the airways.

“This is a really great example where the pig serves as a model for what happens in the human, and the pig reacts to this disease in nearly the same way,” said Randall Prather, distinguished professor of reproductive biotechnology at the University of Missouri. “In contrast, when you use mice, they don’t get the lung disease that is common in patients with cystic fibrosis.”