Cystic fibrosis: an antibiotic cure?

Cystic fibrosis, a lethal, inherited respiratory disease, has flouted attempts at treatment-even gene therapy. Now, an antibiotic commonly used to treat infection in cystic fibrosis patients may combat the illness itself in some patients.

The antibiotic, an aminoglycoside, can overcome the genetic defect that causes cystic fibrosis in 5 percent of patients, according to David M. Bedwell of the University of Alabama at Birmingham and his coworkers. They report their findings in the April Nature Medicine.

The genetic defect involves the CTFR gene. In some people with cystic fibrosis, the gene has abnormalities, called stop mutations, that derail the process of producing the CTFR protein. Lacking that protein, cystic fibrosis patients cannot clear the disease's characteristic thick mucus out of their lungs.

The researchers, building on earlier work showing that aminoglycosides can override stop mutations, exposed damaged CTFR genes to the antibiotic in the lab. They found that the damaged genes produced functioning protein when bathed in the antibiotic.

Ironically, though doctors have routinely prescribed aminoglycosides to combat infections in people with cystic fibrosis, they stop offering the antibiotic when the infection clears. In some patients, continuing the therapy may provide long-term relief from cystic fibrosis itself, Bedwell says.