By Sanjana Malkareddy
By National Institute of Allergy and Infectious Diseases from Unsplash
What is Cystic Fibrosis (CF)?
CF is an inherited disease that severely affects body parts like the lungs and digestive system. CF affects cells that release sweat, mucus, and digestive juices. When these cells work correctly, they secrete fluids that are slippery and slimy. People with CF have a flawed gene that causes the fluids to become adhesive and thick. Due to the quality of these fluids, they tend to clog up ducts, tubes, and passageways. Organs such as the lungs and pancreas are especially prone to this behavior.
There are two types of CF: classic cystic fibrosis and atypical cystic fibrosis. Classic cystic fibrosis is when the disease affects multiple body parts and is typically diagnosed in the first few years of life. Atypical cystic fibrosis is a less severe version of the disease as it can only harm a single organ or symptoms might be on and off. This type of CF is often diagnosed later in life, for example, in older children or adults.
Causes
CF is caused by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. This causes the CFTR protein to malfunction. When the protein is unable to perform, it is incapable of bringing chloride to the surface of the cell. Chloride is a necessary component to attract water to the cell’s surface; as a result, a malfunctioning CFTR protein can result in thick and sticky mucus.
CF is an autosomal recessive genetic disorder, meaning that for a person to have CF both parents must be carriers of the disease and the child must inherit one copy of the defective gene from each parent. Carriers are people who only have one copy of the defective gene. Since CF is autosomal recessive, carriers do not have the disease but are capable of passing the defective gene to their offspring.
How is it diagnosed?
In newborns, CF is diagnosed by taking a blood sample from the infant's heel to check for high levels of immunoreactive trypsinogen (IRT), or a chemical your pancreas produces. Since people with CF have high levels of IRT, this method is a good way to see if the baby might have CF; however, it is not always reliable since IRT levels can also increase due to stressful delivery or premature birth. Another method is a sweat test to check for high amounts of salt, as saltier sweat is also an indicator of CF. Lastly, a genetic test may be done to confirm the diagnosis or to see the specific flaws in the gene responsible for CF. A sweat test or genetic test for CF may be performed for older children and adults, who weren't tested during birth but show symptoms.
Symptoms
Symptoms of classic cystic fibrosis include:
Recurring lung infections (such as bronchitis or pneumonia)
Recurring sinus infections
Trouble breathing (wheezing)
Persistent cough
Oily or loose stool
Slow growth
Inability to gain weight, even with a good diet and calorie intake
Symptoms of atypical cystic fibrosis include:
Unusual electrolyte levels resulting in heat stroke or dehydration
Diarrhea
Pancreatitis
Chronic sinusitis
Weight loss
Nasal polyps
People with this type of CF may also have symptoms similar to people with classic cystic fibrosis.
Effects on Respiratory System
Some common respiratory system complications due to cystic fibrosis include:
Nasal polyps, due to the lining inside the nose becoming swollen and inflamed, polyps can form.
Bronchiectasis is a chronic lung condition characterized by unusual scarring and widening of the bronchial tubes. This makes it difficult to move clear mucus from the bronchial tubes and air through the lungs.
Chronic infections, as mucus builds up and stays in the airways, become an ideal place for bacteria and fungi. As a result, many people with CF experience constant infections such as bronchitis or pneumonia.
Effects on the Digestive System
Some common digestive system complications due to cystic fibrosis include:
Liver disease, such as jaundice or cirrhosis (scarring of the liver), can occur as the tube that carries bile from the liver and gallbladder to the duodenum (the first part of your small intestine) becomes inflamed or obstructed.
Malnutrition can occur when the tubes that carry digestive enzymes become clogged with mucus, preventing them from entering your intestines. As a result, your body is unable to absorb all the nutrients it needs. This can result in weight loss, slow growth, and pancreatitis.
Treatments
Since there is no cure for CF, treatments are primarily focused on relieving symptoms and slowing the progression of the disease. Many medications are available to treat CF some of these medications include:
Medications that go after mutated genes
Inhaled medication that helps keep airways open
Mucus-thinning medications that help cough up mucus
Medications that reduce acid which improves the performance of pancreatic enzymes
Treatment apart from medications includes options that use techniques that help clean up the airways. For example, they help make the thick mucus in the lungs easier to cough up by loosening it. Thus, reducing the risk of inflammation and infection in the airways. Some of those airway-clearing techniques include:
Breathing and coughing techniques to help loosen up mucus and keep it from obstructing your airways
An airway clearance vest which vibrates to help loosen up mucus
Positive expiratory pressure (PEP) forces you to work harder to breathe out, which helps keep your airways open and expel mucus
Some other treatments include having a diet that meets your nutritional needs, pulmonary rehabilitation, and if necessary, surgery.
Citations
About cystic fibrosis. Cystic Fibrosis Foundation. (n.d.). https://www.cff.org/intro-cf/about-cystic-fibrosis
Mayo Foundation for Medical Education and Research. (2021, November 23). Cystic fibrosis. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/cystic-fibrosis/symptoms-causes/syc-20353700
professional, C. C. medical. (n.d.). What is cystic fibrosis?. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/9358-cystic-fibrosis#overview