Cystic fibrosis (CF), also called mucoviscidosis, is an auto-somal hereditary disease that affects the lungs, sweat glands and the digestive system. At the genetic level, cystic fibrosis is the result of an in-frame deletion of three base pairs in the DNA. Cystic fibrosis results from the production of an abnormal form of a protein called cystic fibrosis trans-membrane conductance regulator (CFTR). CFTR functions in transporting chloride ions across epithelial cells found in the lung and intestinal tract. In cystic fibrosis patients, CFTR does not function properly, causing accumulation of ions inside epithelial cells. Since water follows ions by osmosis, this results in water depletion and viscous mucus on the surface of alveolus.
Recent medical research is beginning to show an imbalance of essential fatty acids may play a role in cystic fibrosis. Tissue samples from with cystic fibrosis 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 cystic fibrosis gene and one copy of the normal gene have fatty acid levels in between those of cystic fibrosis 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.
cystic fibrosis symptoms
The symptoms of cystic fibrosis usually develop during early childhood. Both lungs and pancreas produce abnormally viscous mucus. This mucus begins to build up and starts to clog the opening to the pancreas and the lungs. 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, cystic fibrosis 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.
The disease can be diagnosed by common cystic fibrosis symptoms such as a high salt concentration in a baby's sweat or by genetic testing. Males are also frequently sterile because of the obstruction or absence of the vas deferens.
In addition to pulmonary infections, most people with cystic fibrosis 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-soluble 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.
Cystic fibrosis patients often cannot interact with each other, due to worries of cross-infection of MRSA, Pseudomonas, and other bacteria. These infections thrive in the thick mucus of cystic fibrosis patients' lungs and cause complications and possibly even death. Cystic fibrosis patients, thus, should not meet other CF patients with infections other than their own. Because of the risk cystic fibrosis patients face, they must remain in isolation during hospital stays, and special precautions must be taken. This risk previously caused many cystic fibrosis clinics to recommend that cystic fibrosis patients live in isolation and never meet. However recently these views have been changed because of the possible psychological problems this may cause; instead cystic fibrosis patients are encouraged to exercise caution, avoid direct physical contact, and possibly wear surgical masks.
Posted by Staff at June 16, 2005 2:33 AMblog comments powered by Disqus