The symptoms of CF usually develop during early childhood. Both lungs and pancreas produce abnormally viscous mucus. The mucus in the lungs can become a growth medium for bacteria, resulting in chronic respiratory infections and eventual permanent damage to the lung tissue. As lung function deteriorates, CF patients develop pulmonary hypertension and eventually cor pulmonale. Death usually occurs from severe infection or heart failure. These thick secretions also obstruct the pancreas, preventing digestive enzymes from reaching the intestines to help break down and absorb food.
History and Statistics
Cystic fibrosis was first described as a disease in the late 1930s. It is the most common genetic disease among people with European ancestry. Approximately one in every 25 people carries one normal and one CF gene. Since cystic fibrosis is recessive, both copies of the gene have to be CF genes to cause the symptoms that occur in about 1 in every 2500 children. The high incidence of this lethal gene can be explained by the fact that CF carriers, who don't show any symptoms, enjoy some protection against cholera, since the extreme water loss in the intestines is prevented. People from areas where cholera is not a problem show a much lower incidence of CF.
In its most common form, a single amino acid mutation leads to the production of an abnormal transmembrane CFTR protein (cystic fibrosis transmembrane conductance regulator) which functions in transporting chloride ions across epithelial cells found in the lung and intestinal tract. Since water follows ions by osmosis, this results in water depletion and viscous mucus.
Recent medical research is beginning to show that an imbalance of essential fatty acids may play a role in cystic fibrosis. Tissue samples from both mice, and more recently humans, with CF show an excess of arachidonic acid (AA) and a deficiency of docosahexaenoic acid (DHA). Research has also indicated that healthy individuals with one copy of the CF gene and one copy of the normal gene have fatty acid levels in between those of CF patients and people with no CFTR gene mutations. Further research is needed to show how this is linked to the CFTR gene defect and what implications this may have on treatment of Cystic Fibrosis.
CF patients often cannot interact with each other socially due to worries of cross-infection of Pseudomonas, MRSA, Cepacia, and other bacteria. These infections thrive in the thick mucous of CF patients' lungs and cause complications and possibly death. Therefore CF patients who do not have a certain bacteria type cannot meet with those who do. Because of this risk CF patients must remain in isolation during hospital stays, and special precautions must be taken. This risk previously caused many CF-clinics to recommend that CF patients live in isolation and never meet. However recently these views have been changed because of the possible psychological problems this may cause; instead CF patients are encouraged to exercise caution, avoid direct physical contact, and possibly wear surgical masks.
In addition to pulmonary infections, most persons with CF also have problems with digestion, particularly the digestion of fats. This leads to malabsorption and difficulty gaining and maintaining weight, which in turn affects overall health. This is due to the abnormally sticky mucus that blocks the release of digestive enzymes from the pancreas. Pancreatic insufficiency is treated with supplemental enzymes. Usually water-miscible forms of the fat-soluble vitamins A, D, E, and K are required as the decreased fat absorption can lead to deficiencies of these vitamins.
CF patients also have a high incidence of diabetes mellitus because of the pancreatic blockage. The chronic blocking causes the Islets of Langerhans to degrade over time and decrease insulin production, causing hyperglycemia.
Daily chest physiotherapy and aerosol breathing treatments are very commonly prescribed for CF treatment. Typical physical therapy involves manual chest precussion (pounding), or possibly using a device such as the ThAIRapy Vest or the Intrapulmonary Precussive Ventilator (IPV) to achieve the same effect: loosening of the thick mucous. Aresolized medicines commonly given include Albuterol, Ipatropium Bromide, and Pulmozyme to loosen secretions and decrease inflammation. Tobramycin is sometimes given to fight infections, however it causes long-term hearing damage and cannot be used constantly.
CF patients are typically hospitalized somewhat regularly, often every 6 months depending on the severity of the case. Patients often have IV antibiotics through a PICC line or chest port for IV Antibiotics.
Earlier approaches to diabetes treatment among CF patients generally did not address long-term effects because of the short CF life expectancy. However due to improving treatment of CF patients and their resulting longer lifespan, it is increasingly common to address Diabetes symptoms that are not immediately harmful. As maintaing body weight is important for CF patients, a typical diabetic diet is not feasible and therefore insulin doses are instead adjusted to fit the typical high-calorie/high-fat CF diet.
Due to advances in medical treatment, the median life expectancy of a newborn with cystic fibrosis increased from 4 years (in the 1960s) to 32 years today. These procedures include the intake of digestion enzymes, nutritional supplements, percussion and postural drainage of the lungs, improved antibiotics and inhalation of aerosols containing medication. A few attempts of gene therapy were initially successful, but failed to produce acceptable long-term results.
da:cystisk fibrose es:Fibrosis quística nl:mucoviscidose sv:Cystisk fibros