Cystic fibrosis (CF) is a genetic disease affecting about 30,000 children and adults in the U.S. Every year over 3000 infants are born with CF in the U.S. alone. People with CF have changes in the gene that makes an important protein in the cell membranes of the cells that line various mucosal surfaces and glands. Mucosal surfaces are the surfaces on our body that are usually wet and covered with mucus (mouth, lungs, nose, etc.). Mucus is produced by cells and protects the mucosal surface from infection. The mucus has to be thick enough to catch the invading microbes but not too thick. If the mucus is too thick it is very difficult for the body to remove the mucus and it will accumulate. The accumulation of mucus can plug the airways and make breathing quite difficult it also serves as a place for bacteria to reside and CF patients have frequent life-threatening bouts of pneumonia.
The protein affected by CF moves chloride and sodium ions from inside the cell to the mucosal surface. When these ions are transported outside of the cell some of the water inside the cells (intracellular water) will go with it. The movement of intracellular water to the mucus covering the cells thins the mucus allowing it to be removed by the body. However, CF patient's ion transporter protein does not move enough of these ions out of the cells to thin the mucus. As a result the mucus produced in CF patients is very thick and sticky. Many other functions besides lung functioning are affected by CF. It also affects digestion (blocks pancreatic ducts preventing secretion of digestive enzymes into the intestines) and reproduction.
Common symptoms of CF include:
· coughing/wheezing
· infections/ pneumonia
· nasal polyps (bumps inside the nose)
· digestive problems
· poor growth
· salty tasting skin
· infertility
The symptoms and severity of CF differ from person to person. Most patients have both respiratory and digestive problems, while others only have respiratory problems. While CF is usually diagnosed in childhood, people with mild symptoms may not be diagnosed until they are older. CF often becomes worse with age. Many people with CF live into their mid-30s.
Respiratory problems are very common in CF patients. The mucus plugs the lungs and eventually becomes infected by bacteria. Bacteria like Pseudomonas aeruginosa produce toxins that cause damage to the lungs that will cause an inflammatory reaction making it even more difficult for the CF patient to breath. To resolve this problem physicians give antibiotics and find they will help the patient to breath better. The antibiotics usually given do not kill Pseudomonas
