March 5, 2009

Gene modifies cystic fibrosis lung disease

U.S. medical scientists involved in an international study say they've identified a gene that modifies lung disease severity in people with cystic fibrosis.

Wake Forest University Baptist Medical Center researchers said the research is the first published study to search the entire genome looking for genes that modify the severity of cystic fibrosis lung disease.

Carl Langefeld, a study co-author and Wake Forest University School of Medicine researcher, said the findings might help in the identification of targets for drug development and the development of tools for the earlier diagnosis of individuals with cystic fibrosis who are susceptible to severe lung disease.

After analyzing the genetic makeup of nearly 3,000 cystic fibrosis patients, researchers found small genetic differences in a gene called IFRD1 correlate with lung disease severity. They discovered the protein encoded by IFRD1 is particularly abundant in a type of white blood cell called neutrophils, and that it regulates their function.

Neutrophils "¦ are important to the immune system's response to bacterial infection, said senior investigator Dr. Christopher Karp of Cincinnati Children's Hospital Medical Center. In cystic fibrosis, however, neutrophilic airway inflammation is dysregulated, eventually destroying the lung.

The study was reported in the Feb. 25 online edition of the journal Nature in advance of print publication.