September 21, 2012
Dear Mayo Clinic:
What causes cystic fibrosis? Can the disease be cured?
Cystic fibrosis is caused by a genetic defect that makes it hard for salt to move in and out of the cells in a person's body. No cure is available, but treatment can help manage the symptoms of cystic fibrosis and lower a person's risk of complications from this serious disease.
The salt in your body, made up of sodium and chloride, goes in and out of your cells with the help of a protein, called the cystic fibrosis transmembrane regulator, or CFTR protein. When it works the way it should, the salt helps make the body's lining fluids — such as mucus, sweat and digestive juices — thin and slippery. But when the CFTR protein is abnormal because of a genetic problem, as happens in people with cystic fibrosis, the salt cannot do its job. As a result, those fluids become thick and sticky. Instead of acting as lubricants, they plug up the body's ducts and passages.
Cystic fibrosis can lead to a range of symptoms and problems throughout a person's body. The areas most often affected are the lungs and pancreas, often resulting in breathing problems, lung infections, poor nutrient absorption and intestinal blockage. The disease may also have an impact on the paranasal sinuses, liver and gallbladder. People with cystic fibrosis are at high risk for lung damage, chronic infections, diabetes and digestive problems.
Because cystic fibrosis can affect many organ systems, it is important for people who have this disease to work with a health care team that specializes in managing cystic fibrosis. That team should include experts from a range of medical specialties, as well as a care coordinator to help patients and their families manage treatment and provide support.
Although there is no cure for cystic fibrosis, many drugs are available that can help control symptoms and reduce the risk of complications. They include medications to thin mucus and help improve lung function; antibiotics to prevent and control infections; bronchodilators to open airways; and drugs to help the digestive tract absorb more nutrients. There is now one FDA approved drug (ivacaftor, also known as Kalydeco) that helps the CFTR protein to work better in one out of every 25 cystic fibrosis patients with a special mutation known as G551D.
Medications alone are not enough, though. Many people with cystic fibrosis also need to do chest physical therapy every day to loosen thick mucus in the lungs. In addition, nutritional counseling, exercise, special breathing techniques, oxygen therapy and other treatment approaches may be necessary to improve quality of life for a person with cystic fibrosis.
When cystic fibrosis leads to severe lung damage or chronic lung infections, a lung transplant may be recommended. Because the disease affects both lungs, a double transplant is required for cystic fibrosis. The transplanted lungs are not genetically at risk for cystic fibrosis, so that lowers the likelihood of lung problems after a transplant. But transplant recipients still need to be monitored closely to ensure lung health.
For example, if a person's sinuses are affected by cystic fibrosis and the sinuses become infected, the infection may drain into the transplanted lungs, causing a lung infection. Careful, close monitoring of all organ systems is critical both before and after a lung transplant.
Overall, treatment for cystic fibrosis has progressed dramatically from the time the disease was first described in the 1930s. At that time, few children with cystic fibrosis lived past infancy. Today, with advances in treatment and careful management of this disease, many people with cystic fibrosis live into their 40s, 50s and beyond.
— J.P. Scott, M.D., Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, Minn.