Facts About CF

Facts About Cystic Fibrosis

Cystic fibrosis is a genetic disease affecting approximately 30,000 children and adults in the United States.
CF causes the body to produce an abnormally thick, sticky mucus, due to the faulty transport of sodium and chloride (salt) within cells lining organs such as the lungs and pancreas, to their outer surfaces. The thick CF mucus also obstructs the pancreas, preventing enzymes from reaching the intestines to help break down and digest food. Specialized treatments are available to address these problems at CF Foundation-supported care centers across the country.
CF has a variety of symptoms. The most common are: very salty-tasting skin; persistent coughing, wheezing or pneumonia; excessive appetite but poor weight gain; and bulky stools. The sweat test is the standard diagnostic test for cystic fibrosis. This simple and painless test measures the amount of salt in the sweat. A high salt level indicates that a person has CF.
The treatment of CF depends upon the stage of the disease and which organs are involved. One means of treatment, chest physical therapy, requires vigorous percussion (by using cupped hands) on the back and chest to dislodge the thick mucus from the lungs. Antibiotics are also used to treat lung infections and are administered intravenously, via pills, and/or medicated vapors which are inhaled to open up clogged airways. When CF affects the digestive system, the body does not absorb enough nutrients. Therefore, people with CF may need to eat an enriched diet and take both replacement vitamins and enzymes.
One in 31 Americans (one in 28 Caucasians) - more than 10 million people - is an unknowing, symptom less carrier of the defective gene.
An individual must inherit a defective copy of the CF gene — one from each parent — to have cystic fibrosis. Each time two carriers conceive a child, there is a 25 percent chance that the child will have CF; a 50 percent chance that the child will be a carrier; and a 25 percent chance that the child will be a non-carrier.

Progress Toward a Cure

Since the defective CF gene was discovered in 1989, the pace of CF research has greatly accelerated. In 1990, scientists successfully made copies of the normal gene, and added them to CF cells in laboratory dishes, which corrected the defective cells. The next major step was achieved in early 1993 when the first experimental gene therapy treatment was given to a patient with CF. Researchers modified a common cold virus to act as a delivery vehicle - carrying the genes to the CF cells in the airways. Several Foundation-supported studies are underway to test new gene delivery methods, such as fat capsules (liposomes) and synthetic vectors. For more information on CF gene therapy, please refer to the CF Foundation fact sheet entitled, Gene Therapy and CF.

New Treatments

The first new drug therapy developed exclusively for CF in 30 years was approved by the Food and Drug Administration (FDA) in 1993. In clinical trials, this mucus-thinning drug called Pulmozyme^®, reduced the number of respiratory infections and improved lung function. In 1995, a four-year Foundation-supported study showed that the drug, ibuprofen, reduced the rate of lung inflammation in children with CF — under controlled conditions, and in high doses.

In late 1997, the FDA approved the drug TOBI™ (tobramycin solution for inhalation). In clinical trials, this reformulated version of the common antibiotic improved lung function in people with CF and reduced the number of hospital stays. The benefits of TOBI are that it can be delivered in a more concentrated dose directly to the site of CF lung infections more efficiently, and that it is preservative-free. The development of TOBI should lead to a long line of other aerosolized antibiotics for people with CF.

Beyond currently available antibiotics, the CF Foundation pursues novel strategies that will lead to entirely new forms of antibiotics. The promising compound, IB367, represents one of an up-and-coming new class of drugs that should provide physicians unique tools to better manage chronic CF lung infections.

In CF cells, chloride (salt) does not move properly because the protein product of the CF gene is defective-- and makes a faulty channel for the chloride to exit the cell. Scientists are therefore looking for ways to get the chloride out. Scientists at Inspire Pharmaceuticals, Inc. are evaluating INS37217 which is designed to activate an alternative chloride channel in human airways. Early research suggests that it promotes hydration of the mucus and therefore better clearance from the airways as well.

In addition, other treatment strategies to correct the protein product of the gene are currently being tested in clinical trials. What makes these drugs so unique is that researchers appear to be treating the causes of CF, not just the symptoms. However, even better treatments are on the horizon. High-throughput screening for CF opens many doors in the CF drug discovery process by allowing scientists to test more compounds for their ability to treat CF cells in a day than once possible in a year!