Cystic Fibrosis

Cystic fibrosis (CF) is a hereditary disease (Read about "Birth Defects") that affects the body's respiratory and digestive systems (Read about "Respiratory System" "Digestive System") as well as the sweat glands and reproductive system. It is chronic and progressive, according to the National Heart, Lung, and Blood Institute (NHLBI). The disease is most common among white children and young adults. The Cystic Fibrosis Foundation, (CFF) says 30-thousand children and adults in the United States currently have the disease.

What goes wrong

The basic problem in all CF patients has to do with an abnormality in the glands that secrete mucus and sweat. The blame rests on a protein produced by the abnormal CF gene (Read about "Genetics"), according to NHLBI. The defective protein blocks the travel of salt through the body's cell membranes within the lungs and pancreas. The biochemical upset causes the body to produce very thick and sticky mucus, according to CFF. It also causes patients to lose excessive amounts of salt when they sweat, which upsets the mineral balance in the body. (Read about "Sweating") Sweat cools the body, and mucus lubricates many of its key systems. The thick mucus tends to build up in the lungs and the intestines. The end result could be poor nutrition, frequent respiratory infections, problems breathing, heart disease (Read about "The Heart & Cardiovascular System") and lung damage. Lung disease, according to NHLBI is the usual cause of death in most patients.

Symptoms

CF may affect different people in different ways. A baby born with the abnormal CF gene may have symptoms during his or her first year, according to NHLBI. However, NHLBI says the disease may not even show up until the teen years, or beyond that. Infants or young children should be tested for CF if they have the following symptoms, according to NHLBI:

• frequent wheezing
• pneumonia (Read about "Pneumonia")
• chronic cough with thick mucus
• salty-tasting skin
• greasy and foul smelling stools
• diarrhea (Read about "Diarrhea")
• poor growth (Read about "Child Development")

CF can cause other complications including sinusitis (Read about "Sinusitis"), clubbed fingers and toes, liver disease (Read about "The Liver") and diabetes. (Read about "Diabetes") Pneumothorax is considered a common complication of cystic fibrosis, and its incidence increases with age. Pneumothorax is a condition that can lead to a collapsed lung. (Read about "Pneumothorax")

Diagnosis

The sweat test is considered the best way to diagnose CF, according to CFF, however, the organization recommends trained technicians perform the test, and a reliable laboratory evaluates it. (Read about "Laboratory Testing") There are no needles involved during this test, which can reveal if the amount of salt in the sweat is above normal levels. Results are usually available within 24 hours, and once it's positive, it will always be positive according to CFF. In rare cases, test results will fall into a borderline range, and may need to be repeated. The sweat test has helped doctors diagnose CF for the last 40 years.

Anyone of any age can have the test; however, CFF says infants may not make enough sweat. If that is the case NHLBI says a blood test called the immunoreactive trypsinogen test (IRT), may be used. During the IRT test, blood is taken and analyzed for a specific protein.

The gene

The defective CF gene was first discovered in 1989. To have CF, a child must inherit one abnormal gene from each parent, according to NHBLI. Each unaffected parent of an affected child carries one abnormal and one normal CF gene. They don't show any evidence of the disease because, according to NHBLI, the normal CF gene dominates the abnormal one. Both girls and boys can inherit the abnormal gene. CFF says more than 10 million Americans carry the defective gene, but have no symptoms of CF.

Treatment

Treating CF depends on the stage of the disease. According to CFF, the following treatments may help:

• chest physical therapy to dislodge thick mucus from the lungs
• antibiotics to treat lung infections (Read about "Antibiotics")
• dornase alfa to help clear the airways and improve lung function
• hypertonic saline to draw more water into the airways and make it easier to cough out the mucus
• enriched diet
• vitamins (Read about "Vitamins & Minerals")

Treatment for CF is improving, according to the American Association of Respiratory Care (AARC). AARC says that more effective antibiotics are helping with chronic infections. Heart and lung transplants (Read about "Transplants") have also been credited with successfully helping CF patients, according to AARC. New drugs are being brought on line. The past decade has seen the development of a number of new medications to deal with CF.

The future

While there is still no cure for CF, progress is being made in finding new treatments for the defective gene that causes CF, according to AARC. Scientists have had some success with experimental gene therapy, and continue to investigate the possibilities. With that, as well as improved drugs and experience with transplants, AARC says the future looks brighter than ever for people living with CF.

Related Information:

    Respiratory System

    Chronic Obstructive Pulmonary Disease

    Asthma

    The Immune System

    Immune System Glossary