overview
Cystic Fibrosis (CF) is a chronic, progressive, and frequently fatal genetic (inherited) disease of the body's mucus glands. CF primarily affects the respiratory and digestive systems in children and young adults. The sweat glands and the reproductive system are also usually involved in the disease process. On average, individuals with CF have a lifespan of approximately 30-40 years. Each year approximately 1,000 babies are born in the United States with CF. Two-thirds of the infants born with CF will be diagnosed in the first year of life. In all, about 40,000 American adults and children are living with this disorder. Although there's still no cure, 90% of those living with CF have access to life changing modulators and the emerging field of gene therapy may someday help correct lung problems in people with CF.
Signs & Symptoms
The specific signs and symptoms of CF can vary, depending on the severity of the disease, and may also vary with age. In some newborns the first sign may be a blockage of the intestines (meconium ileus). This occurs when meconium tarry, greenish-black stools normally passed by an infant in the first day or two after birth becomes so thick that it can't move through the intestines. Other signs in newborns may include a failure to grow, bulky and greasy stools (steatorrhea) and frequent respiratory infections..
CF does not follow the same pattern in all patients but affects different people in different ways and to varying degrees. However, the basic problem is the same in all patients: an abnormality in the glands, which produce or secrete sweat and mucus. Sweat cools the body; mucus lubricates the respiratory, digestive, and reproductive systems, and prevents tissues from drying out, protecting them from infection. People with CF lose excessive amounts of salt when they sweat. This can upset the balance of minerals in the blood, which may cause abnormal heart rhythms. Mucus in CF patients is very thick and accumulates in the intestines and lungs. The result is malnutrition, poor growth, frequent respiratory infections, breathing difficulties, and eventually permanent lung damage. Lung disease is the usual cause of death in most patients. CF can cause various other medical problems. These include sinusitis (inflammation of the nasal sinuses, which are cavities in the skull behind, above, and on both sides of the nose), nasal polyps (fleshy growths inside the nose), clubbing (rounding and enlargement of fingers and toes), pneumothorax (rupture of lung tissue and trapping of air between the lung and the chest wall), hemoptysis (coughing of blood), cor pulmonale (enlargement of the right side of the heart), abdominal pain and discomfort, gassiness (too much gas in the intestine), and rectal prolapse (protrusion of the rectum through the anus). Liver disease, diabetes, inflammation of the pancreas, and gallstones also occur in some people with CF.
Cause
In CF, a defective gene alters a protein that regulates the normal movement of salt (sodium chloride) in and out of cells. This results in thick, sticky secretions in the respiratory and digestive tracts, as well as in the reproductive system. It also causes increased salt in sweat on the skin. The affected gene, which is inherited from a child's parents, is known as a recessive gene. This means children need to inherit two copies of the gene, one from each parent, in order to have the disease. If children inherit only one copy, they won't develop CF, but they will be carriers and possibly pass the gene to their own children. If two people who carry the defective gene conceive a child, there's a 25 percent chance the child will have CF, a 50 percent chance the child will be a carrier of the CF gene, and a 25 percent chance the child will neither be a carrier nor have the disease. People who carry the CF gene are healthy and have no symptoms of disease. In fact, it's estimated that as many as 10 million people may be carriers of a CF gene and not know it. Currently, it's not possible to identify everyone who carries the gene. But researchers are working to develop a test for all carriers. Although parents often blame themselves when a child is born with CF, it's important to remember that nothing a parent does causes this disease.
Diagnosis
The standard diagnostic test for CF is a sweat test, which measures the amount of sodium and chloride in a person's sweat. During the procedure a small amount of an odorless sweat-producing chemical is applied to a small area on the arms or legs. An electrode attached to the area stimulates a very weak electric current, causing a tingling or warm feeling. After several minutes, sweat is collected from the stimulated area and sent to a laboratory for analysis. The sweat test is performed twice. A consistently high level of salt indicates CF. This test doesn't show whether someone has a mild or severe case of the disease, however, and it can't predict how well someone with CF will do. In addition, the sweat test may not always be useful in newborns. That's because babies may not produce enough sweat for a reliable diagnosis in the first month of life. For this reason, doctors usually don't perform a sweat test until an infant is at least several months old. In some cases your doctor may perform a genetic analysis of a blood sample to confirm a diagnosis of CF. Researchers have identified more than 800 changes in a gene that when paired with another abnormal gene can result in CF. Testing is possible on approximately 30 of the most common genetic mutations. About 90 percent of people with CF can be detected through genetic analysis. Tests may also help determine the extent and severity of CF. Among these are tests to measure how well the lungs, pancreas and liver are working. Because CF is an inherited disease, your doctor may suggest testing of brothers and sisters of a child with CF, even if the siblings show no symptoms. Other family members, especially first cousins, also may want to be tested. In most cases family members can be screened with a sweat test, although in some cases genetic testing may be appropriate.
Treatment
At present time, there is no known cure for Cystic Fibrosis. Treatment are primarily directed at reducing symptoms and slowing down the progress of the disease so that the patient's quality of life is improved. Many treatments exist for the symptoms and complications of CF. The main goal is to treat infections, keep the lungs free of sputum, improve airflow and maintain adequate calories and nutrition. Treatments for CF may include antibiotics, mucus-thinning drugs, bronchodilators, bronchial airway drainage, oral enzymes, and better nutrition.
Newer antibiotics may more effectively fight the bacteria that cause lung infections in people with CF. Oral and intravenous antibiotics have made antibiotic therapy available on an outpatient basis. And aerosolized antibiotics that can be inhaled, such as tobramycin (Tobi), provide medication directly into airways. DNA, the basic material in your white blood cells, is released when these cells attack bacteria in your airways, making the mucus in the airways even thicker. The aerosolized drug dornase alpha (Pulmozyme) is an enzyme that fragments DNA, making mucus thinner and easier to cough up. People with CF need a way to physically remove thick mucus from their lungs. This is often done by manually clapping on the front and back of the chest. In some cases an electric chest clapper, known as a mechanical percussor, is used. Some people may use an inflatable vest with a machine attached that vibrates at high frequency to help cough up secretions. Both adults and children with CF need to have bronchial airway drainage at least twice a day for 20 to 30 minutes. Older children and adults can learn to do this themselves, especially if they use mechanical aids such as vests and percussors. Young children need the aid of parents, grandparents or even older siblings.
CF can result in your becoming malnourished because the pancreatic enzymes needed for digestion don't reach your small intestine. As a result you may need 50 percent to 100 percent more calories than you would if you were healthy. Supplemental high-calorie nutrition, special vitamins and enteric-coated oral pancreatic enzymes can enable you to maintain or even gain weight.
Gene therapy for CF is not yet possible but impressive progress is being made in developing ways to treat the gene abnormality that causes CF. In the laboratory, scientists have been able to grow cells from the nasal passages of CF patients. By introducing the normal gene into these cells, researchers corrected the cells' chloride transport abnormality. The chloride defect has also been corrected in small regions in the nasal passages themselves by giving CF patients the normal gene in nose drops.
Help Our Cause
A donation to the Liv for a Cure Foundation will help fund Cystic Fibrosis research. All funds donated to Liv For a Cure will fund research at the Pulmonary Teaching and Research Program of Ann & Robert H Lurie Children's Hospital. All donations are tax deductible and any size donation is appreciated.
