The surprising finding that people with cystic fibrosis (CF) produce too little airway mucus – rather than too much, as it commonly believed – could lead to more effective treatments for the genetic disorder, say researchers at Wake Forest Baptist Medical Center.
“It has always been thought, but never proven, that CF causes the body to produce too much abnormally thick mucus that accumulates in the lungs and intestines,” said Bruce Rubin, M.D., professor of pediatrics. “However, we have now shown that these patients actually have very little mucus in their airways. This finding could change the way we think about CF treatment.”
The research is reported in this month's issue of the American Journal of Respiratory Cell and Molecular Biology.
CF is a genetic disease that affects about 40,000 children and adults in the United States. The disease is characterized by frequent respiratory infections, breathing difficulties, and eventually, permanent lung damage. Physicians have always believed that the airways fill with mucus, which normally lubricates and protects the respiratory system. Because people with CF have chronic cough and infection it has long been assumed that the airways were full of mucus.
Rubin and colleagues, however, have shown otherwise. They collected sputum from 12 patients with CF and 11 participants without lung disease and analyzed the contents. Participants with CF had significantly less (70 percent and 93 percent) of two proteins that form mucus than participants with healthy lungs.
“This showed unequivocally there is much less mucus in the CF airway,” said Rubin, a pediatric pulmonologist at Wake Forest Baptist’s Brenner Children’s Hospital.
The research was conducted by Markus Henke, M.D., while he was completing a fellowship at Wake Forest Baptist in Rubin’s laboratory. He is now at Philipps-University in Marburg, Germany. Henke has since analyzed the sputum from 35 CF patients and said the results are consistent with the earlier findings.