Treatment for Cystic Fibrosis
The only way to cure CF would be to use gene therapy to replace the defective gene or to give the patient the normal form of the protein before symptoms cause permanent damage.
Because gene therapy is an experimental treatment and requires a great deal more research before it is approved as an option for therapy, the best that doctors can do is treat the symptoms, especially bacterial infections and respiratory discomfort. The major goal in treating CF is to clear the abnormal and excess secretions and control infections in the lungs, and to prevent obstruction in the intestines. For patients with advanced stages of the disease, a lung transplant operation may be necessary.
Although treating the symptoms does not cure the disease, it can greatly improve the quality of life for most patients and has, over the years, increased the average life span of CF patients to 30 years.
Improved therapy includes a combination of improved antibiotics, improved nutrition, availability of antiinflammatories, and more effective pancreatic enzyme supplements. Daily physical therapy and exercise are considered essential for maintaining the best quality of life for the patient. For end-stage disease, lung transplantation (or heart transplant surgery in some patients) is the only definitive treatment.
Generally, the most crucial problem to be addressed is obstructed breathing that results from excessive heavy mucus coating the airways and blocking airflow (see Treatment - lung). The digestive problems that result from impaired pancreatic function are not quite as serious or life threatening, but they do require attention.
Modified Diet to Treat CF
Due to pancreatic disorders, children with CF require a modified diet, including vitamin supplements (vitamins A, D, E, and K) and pancreatic enzymes. Maintaining adequate nutrition is essential. The diet calls for a high-caloric content (twice what is considered normal for the child's age), which is typically low in fat and high in protein. Patients or their caregivers should consult with their health care providers to determine the most appropriate diet.
Because of the reduced water content of the pancreatic secretions in patients with CF, the intestinal walls clog up with thick mucus and eventually cause obstruction and severe damage. The pancreas starts to digest itself (autodigestion). The patient's stools are typically large and bulky due to the high amount of undigested fat (a condition known as steatorrhoea). Additionally, people with CF have reduced bicarbonate secretions, which means that the stomach acids are not adequately neutralized. Pancreatic enzymes work best in an alkaline environment so even when they do make it to the intestines, their effect is minimized because of the highly acid environment. Nearly 90% of all CF patients benefit from pancreatic enzyme replacement therapy.
Pancreatic enzyme supplements (e.g., pancrelipase [Ultresa]) are usually taken at every meal, including snacks. The supplements are derived from pork. Certain religious groups that prohibit the eating of pork have been granted permission to use the pancreatic supplement, as there are no available alternatives. Any patients who are concerned with this should consult someone who can provide them with support.
Pancreatic enzyme supplements are enteric-coated, which means that the enzymes are protected by a special coating so that they do not start working before they reach the small intestine.
High doses of some pancreatic enzymes may lead to the development of colonic strictures, a narrowing of the colon.
Vitamin Supplements to Treat CF
Replacing the fat-soluble vitamins that are not absorbed because of the pancreatic dysfunction is an essential part of maintaining a healthy diet.
H2 Blockers to Treat CF
H2 blockers, also known as H2 receptor antagonists, are a class of drugs that help reduce stomach acid. They are prescribed for CF patients in an effort to create a more alkaline environment so the pancreatic enzymes can do their job. They can help break up clumps of undigested food that lead to distal intestinal obstruction.
What is gene therapy?
Gene therapy is the use of normal DNA to "correct" for the damaged genes that cause disease. In the case of CF, gene therapy involves inhaling a spray that delivers normal DNA to the lungs. The goal is to replace the defective CF gene in the lungs to cure CF or slow the progression of the disease.
According to the National Heart, Lung and Blood Institute (NHLBI), the potential of gene therapy to cure CF has shown promise in the laboratory: if epithelial cells from the nasal passages of CF patients are cultured (grown) in the lab and normal DNA injected into them, the chloride transport abnormality that wreaks havoc in the CF patient is corrected. Some scientists have taken the research one step further: in CF patients who use nose drops containing a normal copy of the CF gene, the chloride transport problem can be corrected in small regions of the nasal passage. This suggests that there may be a way to correct for similarly clogged mucous membranes deeper in the body, such as in the lungs.
There are a lot of questions that need to be answered to push gene therapy to the next level: correcting the chloride transport problem in the lungs and other parts of the body. How can gene therapy be applied so that its effect is long term and does not require repeated administration? What vector(s) do not cause unwanted side effects? And, eventually, how can gene therapy be used to prevent the development of CF?
The experimental nature of gene therapy
Patients and family members need to keep in mind that gene therapy is, at this time, an experimental therapy. The NIH's National Heart, Lung and Blood Institute warns that "this treatment may not be as successful as originally hoped."