Diagnosing and Treating Cystic Fibrosis
In the last 2 decades, there have been many advances in the treatment of CF. There are medications to help thin and clear the thick mucus from the airways, enzymes to help absorb fat and nutrients, and antibiotics to treat the infections. There are also new emerging treatments that target fixing the CFTR protein.
What to Expect
The new classes of CFTR-modifying medications not only improve lung function in older patients but also maintain it when given to younger patients. People with CF will still need to continue taking enzymes to help absorb food and will periodically need treatment with antibiotics for infections, but the frequency should be much less.
How Cystic Fibrosis Is Diagnosed
- Newborn screening. The newborn screen shows infants who have a high level of an enzyme called immunoreactive trypsin in their blood. This occurs when there is injury to the pancreas. The test is repeated if it is abnormal. Some states also combine this with testing for the most common gene mutation called deltaF508. The next step is to refer the infant for further testing as there are many “false-positive” tests. This entails taking a blood sample to check whether the infant has two genes that cause CF and/or performing a sweat test.
- Genetic testing. More than 2,000 gene mutations have been described in CF Most of them are quite rare, but a few are common, like the deltaF508 mutation that is found in at least one gene in 70% of individuals. In most cases, genetic testing is able to determine the exact mutation in most cases. For couples who want to have children, genetic testing is also important as more than 10 million Americans are carriers of a CF gene. For every pregnancy, there is a one-in-four chance that the child will have CF when both parents are carriers.
- Sweat test. Sweat is collected from a small area on the child’s forearm, and the sodium levels are measured. Children with CF have high levels of sodium in their sweat because a lack of CFTR prevents the salt on the skin from being reabsorbed back into the sweat glands.
- Measuring nasal lining. Another way to confirm the diagnosis is to run a small electrical current across the nasal lining (epithelium). Different solutions are applied to the nasal lining and the electrical current is measured. People with CF respond very differently than those without CF to this test, and it may help confirm a diagnosis.
How Cystic Fibrosis Is Treated
Treating the respiratory tract is very important to prevent or slow down the long-term lung damage from CF.
Airway Clearance Therapy
People with CF need to perform “airway clearance therapy” (ACT). This can be done using manual chest physiotherapy or a device called the “VEST.” This jacket vibrates or “flutters” when you breathe through a device. This shakes the mucus in the airways, enabling you to cough it up.
Mucus Thinning Medication
A nebulizer or inhaler is often used before performing ACT. Commonly used medications are albuterol that relaxes the airway and helps mucus to clear, dornase alpha that thins the mucus so that you can cough it up more easily, and hypertonic saline solution that restores moisture and salt to the cell surface in the airway.
Enzymes and Nutrients
Other medications that are very important are pancreatic enzyme replacement therapies. These help the body absorb food and necessary nutrients. Enzymes have to be given before every meal or snack. People with CF also have to take certain vitamins to help absorb fat. Additional salt also needs to be provided in formula or in food.
Antibiotics and Antiinflammatories
Antibiotics are frequently needed to treat bacteria that grow in the mucus. These can be given in one of three ways:
- Orally or by mouth – this is the easiest and cheapest route.
- By inhalation – this is more expensive but very effective.
- Intravenously (IV) – this is usually reserved for those who are sicker.
Antiinflammatory medications have also been found to be helpful in CF. Two medications are currently in use, ibuprofen and azithromycin (an antibiotic that’s used as an antiinflammatory agent in CF).
In 2015 a combination medication called Ivacaftor/Lumicaftor was approved for children aged 12 years and older. This medication helps individuals who carry two genes of the commonest mutation deltaF508 (Class II).
More medications are in clinical trials and expected to be approved in the near future. The medications currently being tested will help those who carry the most common mutation deltaF508 (Class II) and individuals who do not make CFTR protein at all (Class I).
This content was developed in partnership with the CHEST Foundation, the philanthropic arm of the American College of Chest Physicians.