April 22, 2011

Gene Discovery = Hope for Pulmonary Fibrosis

(Ivanhoe Newswire) -- Not much is known about the fatal lung diseases pulmonary fibrosis and interstitial pneumonia. That may change in the near future. Researchers have identified a genetic variation that increases a person's risk of developing pulmonary fibrosis, and in the process, they have uncovered a possible cause for the disease.

Idiopathic pulmonary fibrosis (IPF) and familial interstitial pneumonia (FIP) are fatal lung diseases in which progressive scarring of the lungs prevent oxygen transport to tissues. In most cases, patients with IPF or FIP die of respiratory failure within a few years of diagnosis. IPF and FIP kill about 40,000 people every year-- that's equal to the amount of people who die of breast cancer each year. However, little is known about the diseases. While prior research has focused on the scarring and inflammatory processes of the disease, not much is understood about its biological roots. Recent clinical trials for possible treatments have failed.

In the new study, a team led by researchers at National Jewish Health analyzed the entire genome of 82 families afflicted with IPF or FIP. They found an area of chromosome 11 containing four genes involved in mucus production that had an association with the diseases and then used mapping and sequencing to narrow the search until they found a genetic variation near the MUC5B gene that is strongly associated with the diseases.

Scientists then found the variation exists in 19 percent of the healthy controls, 59 percent of FIP patients and 67 percent of IPF patients. Carrying just one copy of the genetic variation increases the risk of developing FIP and IPF by 6.8- and 9.0-times, respectively, and carrying two copies of the variation increases the risk of IPF by 21.8-times and FIP by 20.8-times.

The researchers also found that the genetic variation increases production of MUC5B by more than 30-times in patients unaffected by IPF or FIP. In addition, they found that MUC5B production is increased in pulmonary fibrosis patients, whether they have the genetic variation or not, leading scientists to believe the excess mucus production may be a possible cause for pulmonary fibrosis.

Max Seibold, PhD, first author and research instructor at National Jewish Health and the Center for Genes, Environment and Health, was quoted as saying: "This discovery not only identifies a major risk factor for pulmonary fibrosis but also points us in an entirely new direction for research into the causes and potential treatments for this difficult disease."

SOURCE: The New England Journal of Medicine, April 2011