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.

These treatment approaches are detailed more fully below:

* Management of lung problems 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. Chest therapy consists of bronchial, or postural, drainage, which is done by placing the patient in a position that allows drainage of the mucus from the lungs. At the same time, the chest or back is clapped (percussed) and vibrated to dislodge the mucus and help it move out of the airways. This process is repeated over different parts of the chest and back to loosen the mucus in different areas of each lung. This procedure has to be done for children by family members but older patients can learn to do it by themselves. Mechanical aids that help chest physical therapy are available commercially. Exercise also helps to loosen the mucus, stimulate coughing to clear the mucus, and improve the patient's overall physical condition. Medications used to help breathing are often aerosolized (misted) and can be inhaled. These medicines include bronchodilators (which widen the breathing tubes), mucolytics (which thin the mucus), and decongestants (which reduce swelling of the membranes of the breathing tubes). A recent advance, approved by the Food and Drug Administration, is an inhaled aerosolized enzyme that thins the mucus by digesting the cellular material trapped in it. Antibiotics to fight lung infections also are used and may be taken orally or in aerosol form, or by injection into a vein. * Management of digestive problems 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. ____________________________________________________________

Gene Therapy-The Future of CF Treatment?

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. Scientists are still looking for answers to many questions about gene therapy.

Some of these questions are: How should the gene be packaged? What are the best ways to get the gene-containing package into the patient's lungs? What will the long-term results of this treatment be? Can the abnormal chloride transport be corrected in other parts of the body? How long will the correction last? And, most importantly, can gene therapy cure or prevent the lung disease in CF? Is It Possible to Detect CF in an Unborn Baby?

Finding out whether a baby is likely to have CF is possible using prenatal genetic tests. However, the tests cannot detect all of the CF gene mutations. Also, because these tests are very expensive and have certain risks to the mother, they are not used for all pregnant women. If there is another child with CF in the family, the expectant mother may request a prenatal test to see if the fetus has CF genes from both parents, is a carrier for one gene, or is altogether free of the CF genes.

There are two special prenatal tests that can be done-either an amniocentesis or chorionic villus biopsy will be performed. In amniocentesis, cells from the fluid surrounding the baby in the mother's womb (called the amniotic fluid) are tested to see if the CF genes common to the parents are present. In chorionic villus biopsy, cells from the tissue that will eventually form the placenta are tested for the CF gene. Can CF Be Prevented? At this time, preventing CF is not possible. In babies with two abnormal CF genes, the disease is already present at birth in some organs, such as the pancreas and liver, but develops only after birth in the lungs. Someday, gene therapy may be used to prevent the lung disease from developing. Yet, CF might be prevented in the future. Since CF occurs only when both parents pass on a CF gene to a child, it could be prevented by identifying all carriers of CF genes. Genetic counselors might then persuade couples who are carriers not to have children. However, as noted, current tests can detect only some of the more than 400 gene mutations and so the tests are only 80-85 percent accurate. Yet, progress in gene therapy and the realization that not all CF mutations are life-threatening should reassure couples. Potential parents who carry the defective gene may choose to have children.

How Can Patients and Their Families and Friends Be Helped To Cope with CF?

CF education helps patients and their families face the physical and emotional effects of the disease and encourages CF patients to lead active, fulfilling lives. Educational programs and materials suitable for both patients of various ages and their parents are available from local CF centers and from local chapters of the CF Foundation. Patients and their families and friends should know that:

* CF parents should not feel guilty or responsible for causing their child's disease; they could not have prevented it.

* Parents should treat their children with CF as normally as possible. They shouldn't be over-protective but should encourage them to be active and self-reliant.

* Family and friends should remember that CF is not contagious; nobody can get it from a patient.

* In families with CF, brothers, sisters, and first cousins of the CF patient should be tested to see if they carry a defective gene, especially if they seem to have a chronic lung or digestive problem. Carriers of the abnormal gene should get genetic counseling.

* Individuals with CF have normal sexual development and can expect to have a normal sex life. However, most, but not all, men are infertile because of a mechanical blockage of sperm and cannot have children. Women with CF can have children, although they may be less fertile than women without CF.

* Patients and families should work closely with doctors and other medical specialists to develop self-management skills that can improve their quality of life. Above all, CF patients and their families should keep a positive attitude. Scientists continue to make significant advances in understanding the genetic and physiological disturbances in CF and in developing new treatment approaches such as gene therapy. The outlook is bright for further improvements in the care of CF patients and even for the discovery of a cure.

For More Information Additional information about CF can be obtained from the following organizations: National Heart, Lung, and Blood Institute (NHLBI) Information Center P.O. Box 30105 Bethesda, MD 20824-0105 Telephone: 301-592-8573 The Cystic Fibrosis Foundation 6931 Arlington Road, #200 Bethesda, MD 20814 Telephone: 301-951-4422 1-800-344-4823 National Diabetes Information Clearinghouse 1 Information Way Bethesda, MD 20892-3560 Telephone: 301-654-3327 1-800-891-5388 U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Public Health Service National Institutes of Health National Heart, Lung, and Blood Institute NIH Publication No. 95-3650 November 1995 .