CYSTIC FIBROSIS
What is Cystic Fibrosis?
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. On the average, individuals
with CF have a lifespan of approximately 30 years.
What are the Symptoms of Cystic Fibrosis?
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-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. Going into shock is also a risk.
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.
How is Cystic Fibrosis Diagnosed?
The most common test for CF is called the sweat test. It measures the amount of salt (sodium chloride) in the sweat. The sweat test may not work well in newborns because they do not produce enough sweat. In that case, another type of test, such as the immunoreactive trypsinogen test (IRT), may be used. In the IRT test, blood drawn 2 to 3 days after birth is analyzed for a specific protein called trypsinogen. Positive IRT tests must be confirmed by sweat and other tests.
Also, a small percentage of people with CF have normal sweat chloride levels. They can only be diagnosed by chemical tests for the presence of the mutated gene. Some of the other tests that can assist in the diagnosis of CF are chest x-rays, lung function tests, and sputum (phlegm) cultures. Stool examinations can help identify the digestive abnormalities that are typical of CF.
How is Cystic Fibrosis Treated?
Since CF is a genetic disease, the only way to prevent or cure it would be with gene therapy at an early age. Ideally, gene therapy could repair or replace the defective gene. Another option for treatment would be to give a person with CF the active form of the protein product that is scarce or missing.
At present, neither gene therapy nor any other kind of treatment exists for the basic causes of CF, although several drug-based approaches are being investigated. In the meantime, the best that doctors can do is to ease the symptoms of CF or slow the progress of the disease so the patient's quality of life is improved. This is achieved by antibiotic therapy combined with treatments to clear the thick mucus from the lungs. The therapy is tailored to the needs of each patient. For patients whose disease is very advanced, lung transplantation may be an option.
CF was once always fatal in childhood. Better treatment methods developed over the past 20 years have increased the average lifespan of CF patients to nearly 30 years.
A major focus of CF treatment is the obstructed breathing that causes frequent lung infections. Physical therapy, exercise, and medications are used to reduce the mucus blockage of the lung's airways.
The digestive problems in CF are less serious and more easily managed than those in the lungs. A well-balanced, high-caloric diet, low in fat and high in protein, and pancreatic enzymes (which help digestion) are often prescribed. Supplements of vitamins A, D, E, and K are given to ensure good nutrition. Enemas and mucolytic agents are used to treat intestinal obstructions.
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