Cystic Fibrosis

This information about cystic fibrosis is an answer to a question that was posed on an upcoming lab for my biology class.

What is Cystic Fibrosis and what specific tissues in the lung does it affect?

CF is caused by a mutation in a gene called the cystic fibrosis transmembrane conductance regulator (CFTR). This gene helps create sweat, digestive juices, and mucus. Although most people without CF have two working copies of the CFTR gene, only one is needed to prevent cystic fibrosis. CF develops when neither gene works normally. Therefore, CF is considered an autosomal recessive disease. The name cystic fibrosis refers to the characteristic scarring (fibrosis) and cyst formation within the pancreas.
The symptoms of cystic fibrosis depend on the age of the individual, the extent to which the disease affects specific organs, and the types of infections experienced. Cystic fibrosis affects the entire body and impacts growth, breathing, digestion, and reproduction. The newborn period may be marked by poor weight gain and intestinal blockage caused by thick feces. Other symptoms of CF appear during growth and early adulthood. These include continued problems with growth, the onset of lung disease, and increasing difficulties with poor absorption of vitamins and nutrients by the gastrointestinal tract.
Lung disease results from clogging of the smaller airways with thick mucus. Inflammation and infection damage the lungs and the resulting damage leads to a variety of symptoms. In the early stages, incessant coughing, copious phlegm production, and decreased tolerance of exertion are common. Sometimes bacteria that normally inhabit the thick mucus grow out of control and cause pneumonia. In later stages of CF, changes in the architecture of the lung further exacerbate chronic respiratory difficulties. Other symptoms include coughing up blood, changes in the major airways in the lungs, known as bronchiectasis, pulmonary hypertension, heart failure, hypoxia, and respiratory failure requiring support with breathing masks such as bilevel positive airway pressure machines or ventilators.
In addition to typical bacterial infections, people with CF more commonly develop other types of lung disease. The lungs of individuals with cystic fibrosis are colonized and infected by bacteria from an early age. These bacteria, which often spread amongst individuals with CF, thrive in the altered mucus, which collects in the small airways of the lungs. This mucus encourages the development of bacterial microenvironments (biofilms) that are difficult for immune cells and antibiotics to penetrate. The lungs respond to repeated damage by thick secretions and chronic infections by gradually remodeling the lower airways (bronchiectasis), making infection even more difficult to eradicate.
Over time, both the types of bacteria and their individual characteristics change in individuals with CF. Initially, common bacteria such as Staphylococcus aureus and Hemophilus influenzae colonize and infect the lungs. Eventually, however, Pseudomonas aeruginosa and sometimes Burkholderia cepacia dominate. Once within the lungs, these bacteria adapt to the environment and develop resistance to commonly used antibiotics. Pseudomonas can develop special characteristics which allows the formation of large colonies. These strains are known as "mucoid" Pseudomonas and are rarely seen in people who do not have CF. Among these are allergic bronchopulmonary aspergillosis, in which the body's response to the common fungus Aspergillus fumigatus causes worsening of breathing problems. Another is infection with mycobacterium avium complex (MAC), a group of bacteria related to tuberculosis which can cause further lung damage. MAC does not respond to common antibiotics.
Mucus in the paranasal sinuses is equally thick and may cause blockage of the sinus passages, leading to infection. This may cause facial pain, fever, nasal drainage, and headaches. Individuals with CF may develop nasal polyps due to inflammation from chronic sinus infections. Such polyps can block the nasal passages and increase breathing difficulties.
Most information gathered from Wikipedia at http://www.wikipedia.org/wiki/Cystic_Fibrosis

Many people with cystic fibrosis do not live beyond their early 20's. Norma far surpassed that. She is 45 years old and has created a website with extensive information on the disease. Click the title link to visit this interesting and informative resource.