Cystic fibrosis (CF) is a genetic disorder that causes problems with breathing and digestion. CF affects about 35,000 people in the United States. People with CF have mucus that is too thick and sticky, which

• blocks airways and leads to lung damage;
• traps germs and makes infections more likely; and
• prevents proteins needed for digestion from reaching the intestines, which decreases the body’s ability to absorb nutrients from food.

CF affects many different organs in the body, making people with the disease more likely to develop other health conditions including diabetes, cirrhosis (liver disease), arthritis, reflux, hypersplenism (overactive spleen), and osteoporosis.

CF results from mutations (changes) in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene, which has instructions for making the CFTR protein. Everyone has two copies of the CFTR gene, one copy inherited from their mother and one from their father. A person must have mutations in both copies of the CFTR gene to have CF. This means that parents who each have a mutation in only one copy of the CFTR gene, and therefore do not have the disorder themselves, can together have a child with CF. Current recommendations state that all women who are pregnant or planning a pregnancy should be offered carrier screening to see if they could have a child with CF. However, the carrier screening offered to all women does not include all possible CF mutations. Because CF sometimes runs in families, if you have a family history of CF and decide to get screened, talk to your doctor to make sure that you are tested for the right mutation. Your doctor might refer you for genetic counseling and testing.

All babies born in the United States are checked for CF soon after birth as part of newborn screening. Finding babies with CF early is important so that they can start treatment right away, which can help delay or prevent complications of the disorder. Some people with CF show signs of the disorder soon after birth, although in milder cases, signs might not be seen until adulthood.

Signs of CF include

• salty-tasting skin
• cough that doesn’t go away, often with thick mucus or blood
• wheezing or shortness of breath
• frequent lung or sinus infections
• nasal polyps (growths in the nose)
• poor growth or weight gain in childhood
• greasy, bad-smelling stools or constipation
• male infertility

Talk to your doctor if you or your child shows signs of CF. A sweat test or genetic testing might be needed. If you or your child have been diagnosed with CF, you can find a CF Care Center near you.

Treatments for CF focus on improving breathing and digestion, preventing and treating infections, and thinning mucus. Treatments include medicines, therapy to clear mucus out of the lungs, and in some cases, lung transplant. Pharmacogenomic approaches have led to the development of medicines that target the underlying cause of the disorder. Because different CFTR mutations have different effects on the CFTR protein, these medicines can only be used to treat people with certain CFTR mutations.

Cystic fibrosis is an inherited disease characterized by the buildup of thick, sticky mucus that can damage many of the body's organs. The disorder's most common signs and symptoms include progressive damage to the respiratory system and chronic digestive system problems. The features of the disorder and their severity varies among affected individuals.

Mucus is a slippery substance that lubricates and protects the linings of the airways, digestive system, reproductive system, and other organs and tissues. In people with cystic fibrosis, the body produces mucus that is abnormally thick and sticky. This abnormal mucus can clog the airways, leading to severe problems with breathing and bacterial infections in the lungs. These infections cause chronic coughing, wheezing, and inflammation. Over time, mucus buildup and infections result in permanent lung damage, including the formation of scar tissue (fibrosis) and cysts in the lungs.

Most people with cystic fibrosis also have digestive problems. Some affected babies have meconium ileus, a blockage of the intestine that occurs shortly after birth. Other digestive problems result from a buildup of thick, sticky mucus in the pancreas. The pancreas is an organ that produces insulin (a hormone that helps control blood glucose levels). It also makes enzymes that help digest food. In people with cystic fibrosis, mucus often damages the pancreas, impairing its ability to produce insulin and digestive enzymes. Problems with digestion can lead to diarrhea, malnutrition, poor growth, and weight loss. In adolescence or adulthood, a shortage of insulin can cause a form of diabetes known as cystic fibrosis-related diabetes mellitus (CFRDM).

Cystic fibrosis used to be considered a fatal disease of childhood. With improved treatments and better ways to manage the disease, many people with cystic fibrosis now live well into adulthood. Adults with cystic fibrosis experience health problems affecting the respiratory, digestive, and reproductive systems. Most men with cystic fibrosis have congenital bilateral absence of the vas deferens (CBAVD), a condition in which the tubes that carry sperm (the vas deferens) are blocked by mucus and do not develop properly. Men with CBAVD are unable to father children (infertile) unless they undergo fertility treatment. Women with cystic fibrosis may experience complications in pregnancy.

Mucus has several names. Snot, the sticky goo that pours from your nose during a cold. Or phlegm, the gunk that can clog your lungs and make you cough. You probably aren’t a fan of the stuff. But mucus is so much more than a runny nose. Your body is making mucus all the time. And it plays an important role in keeping you healthy.

“Mucus and phlegm get sort of a bad reputation,” says Dr. Richard Boucher, a lung expert at the University of North Carolina. “People think about it as something you’re supposed to cough up and get out. That it’s a bad thing. But in truth, mucus really is the interface between you and the outside world.”

Mucus lines the moist surfaces of your body like the lungs, sinuses, mouth, stomach, and intestines. Even your eyes are coated with a thin layer of mucus. It serves as a lubricant to keep tissues from drying out. It’s also a line of defense.

“Mucus is very important for filtering out materials that you breathe in through your nose, such as dust and allergens and microorganisms,” says Dr. Andrew Lane, an ear, nose, and throat expert at Johns Hopkins University. “Anything that you breathe in gets stuck in the mucus, like flypaper.”

Sweat is a clear, salty liquid produced by glands in your skin. Sweating is how your body cools itself. You sweat mainly under your arms and on your feet and palms. When sweat mixes with bacteria on your skin, it can cause a smell. Bathing regularly and using antiperspirants or deodorants can help control the odor.

Sweating a lot is normal when it is hot or when you exercise, are anxious, or have a fever. It also happens during menopause. If you often sweat too much, it's called hyperhidrosis. Causes include thyroid or nervous system disorders, low blood sugar, or another health problem.

Sweating too little, anhidrosis, can be life-threatening because your body can overheat. Causes of anhidrosis include dehydration, burns, and some skin and nerve disorders.

Cystic fibrosis is a common genetic disease within the white population in the United States. The disease occurs in 1 in 2,500 to 3,500 white newborns. Cystic fibrosis is less common in other ethnic groups, affecting about 1 in 17,000 African Americans and 1 in 31,000 Asian Americans.

Cystic fibrosis is an inherited disease caused by mutations in a gene called the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The CFTR gene provides instructions for the CFTR protein. The CFTR protein is located in every organ of the body that makes mucus, including the lungs, liver, pancreas, and intestines, as well as sweat glands. The CFTR protein has also been found in other cells in the body, such as cells of the heart and the immune system. The mutations in the CFTR gene cause the CFTR protein to not work properly. This causes thick, sticky mucus and blockages in the lungs and digestive system.

Normally, mucus coats tiny hair-like structures called cilia in the airways of your lungs, which sweep the mucus particles up to the nose and mouth where your body can get rid of them. In people who have cystic fibrosis, this process does not work properly.

What gene mutations cause cystic fibrosis?

There are almost 2,000 known disease-causing mutations of the CFTR gene. Different mutations have different effects on how the CFTR protein is made and how it works. In the most common gene mutation, part of the CFTR gene is missing, resulting in a protein that does not work properly.

Normally, the CFTR protein controls the movement of ions from inside the cell to outside the cell. In people who have cystic fibrosis, the mutated gene causes the protein to not work properly, which, in turn, affects the movement of sodium and water. When this happens, the sweat glands make sweat that is saltier than it is in people who do not have cystic fibrosis. To diagnose cystic fibrosis, your doctor will assess your symptoms and recommend some tests, including a sweat test for high sweat chloride. Also, there is less water in the mucus, which makes the mucus thick and sticky. The thick mucus creates blockages in the lungs and digestive system.

How is cystic fibrosis inherited?

Every person inherits two CFTR genes, one gene from each parent. Children who inherit a CFTR gene with a mutation from both parents will have cystic fibrosis. When a mutated CFTR gene is inherited from only one parent and a normal CFTR gene is inherited from the other, the person will be a cystic fibrosis carrier. CF carriers are generally healthy, but they can pass the mutated CFTR gene on to their children.

The image below shows how two parents who are both CF carriers can pass a CFTR gene mutation on to their children.

A person inherits two copies of the CFTR gene, one from each parent. If each parent has a normal CFTR gene and a mutated CFTR gene, each child has a 25% chance of inheriting two normal genes, a 50% chance of inheriting one normal gene and one gene with a mutation and being a cystic fibrosis carrier, and a 25% chance of inheriting two genes with mutations and having cystic fibrosis.

Normal Function

The CFTR gene provides instructions for making a protein called the CF transmembrane conductance regulator (CFTR). This protein functions as a channel across the membrane of cells that produce mucus, sweat, saliva, tears, and digestive enzymes. The channel transports negatively charged particles called chloride ions into and out of cells. The transport of chloride ions helps control the movement of water in tissues, which is necessary for the production of thin, freely flowing mucus. Mucus is a slippery substance that lubricates and protects the lining of the airways, digestive system, reproductive system, and other organs and tissues.

The CFTR protein also regulates the function of other channels, such as those that transport positively charged particles called sodium ions across cell membranes. These channels are necessary for the normal function of organs such as the lungs and pancreas.

Health Conditions Related to Genetic Changes

Congenital bilateral absence of the vas deferens

About 80 CFTR mutations have been identified in males with congenital bilateral absence of the vas deferens. Most affected males have a mild mutation in at least one copy of the gene in each cell. These mutations allow the CFTR protein to retain some of its function. Some affected males have a mild mutation in one copy of the CFTR gene in each cell and a more severe, cystic fibrosis-causing mutation in the other copy of the gene.

Mutations in the CFTR gene disrupt the function of the chloride channel, preventing the usual flow of chloride ions and water into and out of cells. As a result, cells in the male genital tract produce mucus that is abnormally thick and sticky. This mucus clogs the tubes that carry sperm from the testes (the vas deferens) as they are forming, causing them to deteriorate before birth. Without the vas deferens, sperm cannot be transported from the testes to become part of semen. Men with congenital bilateral absence of the vas deferens are unable to father children (infertile) unless they use assisted reproductive technologies.

Cystic fibrosis

More than 1,000 mutations in the CFTR gene have been identified in people with cystic fibrosis. Most of these mutations change single protein building blocks (amino acids) in the CFTR protein or delete a small amount of DNA from the CFTR gene. The most common mutation, called delta F508, is a deletion of one amino acid at position 508 in the CFTR protein. The resulting abnormal channel breaks down shortly after it is made, so it never reaches the cell membrane to transport chloride ions.

Disease-causing mutations in the CFTR gene alter the production, structure, or stability of the chloride channel. All of these changes prevent the channel from functioning properly, which impairs the transport of chloride ions and the movement of water into and out of cells. As a result, cells that line the passageways of the lungs, pancreas, and other organs produce mucus that is abnormally thick and sticky. The abnormal mucus obstructs the airways and glands, leading to the characteristic signs and symptoms of cystic fibrosis.

Hereditary pancreatitis

MedlinePlus Genetics provides information about Hereditary pancreatitis

Other disorders

A few mutations in the CFTR gene have been identified in people with isolated problems affecting the digestive or respiratory system. For example, CFTR mutations have been found in some cases of idiopathic pancreatitis, an inflammation of the pancreas that causes abdominal pain, nausea, vomiting, and fever. Although CFTR mutations may be a risk factor, the cause of idiopathic pancreatitis is unknown.

Changes in the CFTR gene also have been associated with rhinosinusitis, which is a chronic inflammation of the tissues that line the sinuses. This condition causes sinus pain and pressure, headache, fever, and nasal congestion or drainage. Other respiratory problems, including several conditions that partially block the airways and interfere with breathing, are also associated with CFTR mutations. These conditions include bronchiectasis, which damages the passages leading from the windpipe to the lungs (the bronchi), and allergic bronchopulmonary aspergillosis, which results from hypersensitivity to a certain type of fungal infection. Additional genetic and environmental factors likely play a part in determining the risk of these complex conditions.

Other Names for This Gene

• ABC35
• ABCC7
• cAMP-dependent chloride channel
• CF
• CFTR_HUMAN
• cystic fibrosis transmembrane conductance regulator (ATP-binding cassette sub-family C, member 7)
• cystic fibrosis transmembrane conductance regulator, ATP-binding cassette (sub-family C, member 7)
• MRP7

Genomic Location

CF is inherited in an autosomal recessive manner. This means that to have CF, a person must have a mutation in both copies of the CFTR gene in each cell. People with CF inherit one mutated copy of the gene from each parent, who is referred to as a carrier. Carriers of an autosomal recessive condition typically do not have any signs or symptoms.

When two carriers of an autosomal recessive condition have children, each child has a:

• 25% (1 in 4) chance to have CF
• 50% (1 in 2) chance to be a carrier of CF like each parent
• 25% chance to not have CF and not be a carrier

When a carrier of CF has a child with a person with CF, each child has a:

• 50% (1 in 2) chance to have CF
• 50% (1 in 2) chance to be a carrier of CF

Symptoms of cystic fibrosis depend on which organs are affected and the severity of the condition. Most people who have cystic fibrosis have noticeable symptoms. Some people have few or no symptoms, while others experience severe symptoms or life-threatening complications. Symptoms may also change over time.

Cystic fibrosis most commonly affects the lungs. Some people who have cystic fibrosis may have wheezing and a cough that may produce mucus or blood.

Other symptoms depend on the organs affected and may include:

• Blockage of the intestine in a baby soon after birth
• Clubbing of fingers and toes due to less oxygen getting to the hands and feet
• Fever, which may include night sweats
• Gastrointestinal symptoms, such as severe abdominal pain, chronic diarrhea, or constipation
• jaundice, or yellow skin, for an abnormally long time after birth
• Low body mass index (BMI) or being underweight
• Muscle and joint pain
• Delayed growth or puberty
• Salty skin and saltier than normal sweat
• sinuses infections

When to call the doctor

Cystic fibrosis may have serious complications. Call your doctor right away if you believe you have any of the following.

• Pulmonary exacerbation involves a worsening of lung symptoms, such as more coughing or wheezing, chest congestion, and a change in mucus color. You may also have weight loss, a poor appetite, or fever.
• Coughing or spitting up of blood may be a sign that an artery has broken and is bleeding into the airway.
• Sudden shortness of breath or chest pain may be a sign of a pneumothorax, or collapsed lung.

Your doctor may diagnose cystic fibrosis based on your symptoms and results from certain screening tests, such as genetic and sweat tests.

Screening for cystic fibrosis

Genetic testing may be performed to look for carriers, as well as to screen relatives of people who have cystic fibrosis. Genetic testing may also be used as prenatal screening tool to look for a mutated CFTR gene. All newborns in the United States are now screened for cystic fibrosis. Since universal screening for cystic fibrosis began relatively recently, there are still young people and adults who have not been screened.

Carrier screening to detect CFTR mutations

Genetic testing can tell you if you carry a mutation of the CFTR gene. This is called carrier testing. People who have inherited a mutation of the CFTR gene from one parent are cystic fibrosis carriers. People who have inherited a mutation of the CFTR gene from both parents will have cystic fibrosis. Learn more about how cystic fibrosis is inherited. Genetic testing looks at your DNA from a blood or saliva sample, or cells from the inside of your cheek.

The standard test to check for possible cystic fibrosis carriers looks for 23 of the most common disease-causing gene mutations. If you have a positive test, there is a 99% chance you are a carrier. However, if you have a negative test, there is still a small chance that you could carry a CFTR mutation that did not show up on the test.

Siblings of a person who has cystic fibrosis may want to be tested for cystic fibrosis whether or not they have symptoms. Other relatives, such as first cousins and half-siblings, may be tested if they have symptoms, or if the family is concerned that the individual may have cystic fibrosis.

After a positive screening test, the diagnosis should be confirmed with further testing.

Prenatal screening

Couples who are planning to have children may want to be tested to see if they are cystic fibrosis carriers. Genetic testing, such as the carrier screening described above, may be done before or during pregnancy. Often, the mother is tested first. However, if you are already pregnant, you and your partner may choose to be tested at the same time. If the father has a family history of cystic fibrosis, he may be tested first. Similar to standard genetic testing, prenatal screening uses a sample of blood, saliva, or cells from the inside of your cheek to check your DNA.

If one partner is a carrier for a cystic fibrosis gene mutation, then the next step is to test the partner if this has not been done. If both parents are cystic fibrosis carriers, then prenatal diagnostic testing may be performed to see whether your unborn baby has cystic fibrosis or is a carrier.

Newborn screening

When a child has cystic fibrosis, it is very important to diagnose it early to help prevent complications. Newborn screening for cystic fibrosis is performed during a baby’s first 2 to 3 days of life. A few drops of blood from a heel prick are placed on a special card and analyzed in labs.

The type of newborn screening that is performed varies from state to state. Every state and the District of Columbia begins with a blood test to check for levels of a chemical made by the pancreas called immunoreactive trypsinogen (IRT). In people who have cystic fibrosis, IRT tends to be high. However, most babies with high levels of IRT do not have cystic fibrosis. IRT may also be high if the baby is premature, had a stressful delivery, or is a carrier of cystic fibrosis.

Some states test only IRT for cystic fibrosis newborn screening. Other states test IRT and also perform DNA testing. In states that test both IRT and DNA, if IRT is high, then the hospital will test the baby’s DNA for some of the gene mutations that cause cystic fibrosis.

After a positive screening test, the diagnosis should be confirmed with further testing.

Sweat test

A sweat test checks for high levels of chloride in your sweat. The sweat test is the standard test for diagnosing cystic fibrosis. It may be used if you have symptoms that may indicate cystic fibrosis or to confirm a positive diagnosis from a screening of your newborn baby. A normal sweat chloride test alone does not mean you do not have cystic fibrosis. Lower levels of chloride may indicate the need for further testing to diagnose or rule out cystic fibrosis.

How is a sweat chloride test performed?

The sweat test detects a higher amount of chloride — a component of salt — in the sweat of people who have cystic fibrosis. In order to make sweat for this test, a colorless, odorless chemical and a little electrical stimulation are applied to a small area of a person’s arm or leg. The sweat is collected and sent to a hospital lab for testing.

Newborn screening for cystic fibrosis is done using a small amount of blood collected from your baby’s heel. During screening, a special machine measures how much of a certain substance (called immunoreactive trypsinogen or IRT) is in your baby’s blood. IRT is made in the pancreas and is increased in newborns with cystic fibrosis.

In most cases, if a baby’s IRT is elevated, a second test will also be done on the newborn screening sample. This second test looks for changes in the gene that causes cystic fibrosis (called CFTR). Babies with high levels of IRT and at least one change in the CFTR gene may have cystic fibrosis.

Newborn screening for cystic fibrosis is important even if a mother already received screening during pregnancy. In some cases, newborn screening for cystic fibrosis may show different results than prenatal testing. It is important to always follow-up with an out-of-range newborn screening result– even if testing during pregnancy was normal.

What Happens After an Out-of-Range Screening Result?

If your baby’s blood spot screening result for cystic fibrosis is out-of-range, your baby’s health care provider will contact you. Together, you will discuss next steps and follow-up plans.

If your baby’s screening results show high IRT levels and only one change in the CFTR gene, this result does not mean that your baby definitely has cystic fibrosis. It does mean that your baby needs more follow-up testing.

If your baby’s screening results show high IRT levels and two or more changes in the CFTR gene, it is likely that your baby has cystic fibrosis and needs more follow-up testing.

Your baby may need the following tests after an out-of-range screening result:

• Sweat testing to check for the presence of increased chloride (salt)
• Blood and/or urine tests
• Genetic testing using a blood sample

You should complete any recommended follow-up testing as soon as possible. Babies with this condition can have serious health problems if they are not diagnosed and treated quickly.

False-positive newborn screening results for this condition can happen in the following cases:

• Babies who are cystic fibrosis carriers
• Babies whose screening samples were collected before they were 24 hours old
• Babies who are very sick with conditions other than cystic fibrosis

False-negative newborn screening results for this condition can also happen. In some cases, babies with cystic fibrosis have normal levels of IRT and do not get picked up by screening.

Newborn screening helps babies lead healthier lives. If your baby has an out-of-range result, follow up with your health care provider quickly. It is important to follow their instructions. Your baby may need to get treatment right away, even if they are not showing signs or symptoms. In some cases, your baby’s health care provider may decide it is best to watch (monitor) your baby to decide next steps. Careful monitoring and early treatment will help your baby stay as healthy as possible.

While there is not yet a cure for cystic fibrosis, advances in treatment are helping people live longer, healthier lives. To better manage your condition, you or your child will work with cystic fibrosis specialists. In newborns with a positive screening result, treatment may begin while the diagnosis is being confirmed. Treatment for cystic fibrosis is focused on airway clearance, medicines to improve the function of the faulty CFTR protein and prevent complications, and surgery, if needed.

Your healthcare team

Your healthcare team will likely include a cystic fibrosis specialist. This is a doctor who is familiar with the complex nature of cystic fibrosis. Your doctor may work with a medical team that specializes in cystic fibrosis, often at major medical centers.

The United States has more than 100 CF Care Centers, with medical teams that include:

• Doctors specializing in the lungs, diabetes, and the digestive system
• Genetic counselors
• Nurses
• Nutritionists and dietitians
• Pharmacists
• Physical therapists
• Psychologists
• Respiratory therapists
• Social workers

Airway clearance techniques

Airway clearance techniques help loosen lung mucus so it can be cleared, reducing infections and improving breathing. The techniques include special ways of breathing and coughing, devices used by mouth and therapy vests that use vibrations to loosen mucus, and chest physical therapy. These techniques are often used along with medicines such as bronchodilators and mucus thinners.

Medicines

Medicines to treat cystic fibrosis include those used to maintain and improve lung function, fight infections, clear mucus and help breathing, and work on the faulty CFTR protein.

• Antibiotics prevent or treat lung infections and improve lung function. Your doctor may prescribe oral, inhaled, or intravenous (IV) antibiotics.
• Anti-inflammatory medicines, such as ibuprofen or corticosteroids, reduce inflammation. Inflammation causes many of the changes in cystic fibrosis, such as lung disease. Ibuprofen is especially beneficial for children, but side effects can include kidney and stomach problems. Corticosteroids can cause bone thinning and increased blood sugar and blood pressure.
• Bronchodilators relax and open airways. These treatments are taken by inhaling them.
• CFTR modulators improve the function of the faulty CFTR protein. They improve lung function and help prevent lung problems and other complications. Examples include ivacaftor and lumacaftor and a triple combination medicine (elexacaftor–tezacaftor–ivacaftor). The combination medicine is the first approved treatment that may help up to 90% of people who have cystic fibrosis. It is currently approved to use in adults and children older than 12 years.
• Mucus thinners make it easier to clear the mucus from your airways. These treatments are taken by inhaling them.

Surgery

Surgery may be an option for people with advanced conditions.

• A lung transplant may help people with advanced lung disease and respiratory failure.
• A liver transplant may be an option for advanced liver disease such as cirrhosis.

In people with cystic fibrosis, a protein that normally releases bicarbonate (red spheres) from the cell is missing or defective (brown ribbon). Amphotericin B (white) can form channels to release bicarbonate, restoring the antibiotic properties of the airway surface.Rebecca Schultz, Carle Illinois College of Medicine

At a Glance

• A widely used antifungal drug replaced the function of the mutated protein that causes cystic fibrosis in human lung cells grown in the lab.
• The findings suggest a potential therapy for treating people with this life-threatening genetic disorder that causes serious damage to the lungs.

Cystic fibrosis is a genetic condition that causes thick mucus to clog the lungs. This can lead to repeated infections, scarring, and gradual deterioration. It’s caused by a defect in the gene for CFTR (cystic fibrosis transmembrane conductance regulator).

CFTR forms a channel in cell membranes to control the movement of molecules (like salt, water, and bicarbonate) in and out of the cells that line the lung. In people with cystic fibrosis, defective CFTR proteins prevent lung cells from secreting bicarbonate and chloride ions. This causes the mucus on the lung cells to become more acidic and sticky. The sticky mucus impairs the lung’s ability to remove harmful bacteria that are breathed in.

While some treatments are currently available, they are limited because different people have different types of mutated proteins. Some people make no CFTR protein at all.

Amphotericin B is an antifungal medication that can form a channel to allow molecules in and out of the cell. To test whether amphotericin B can replace the function of defective CFTR protein, a team led by Dr. Martin D. Burke at the University of Illinois in Champaign tested the small molecule in an animal model and lung tissue from patients with cystic fibrosis. The research was supported in part by NIH’s National Heart, Lung, and Blood Institute (NHLBI). Results were published online on March 13, 2019, in Nature.

The researchers compared amphotericin B with another drug called ivacaftor, which is known to improve the function of CFTR proteins with specific mutations. In human lung cells grown in the lab, both drugs improved pH levels and bicarbonate secretion, and decreased the viscosity of the liquid on lung cells to a similar degree.

However, in cells with mutated CFTR that doesn’t insert into the cell membrane and those that don’t make CFTR at all, only amphotericin B was able to restore function, since it bypasses the CFTR protein.

The team next administered amphotericin B in an animal model of cystic fibrosis and found improved pH levels in the liquid on lung cells. The researchers noted that amphotericin can be delivered directly to the lungs to avoid common side effects.

“The cystic fibrosis community is truly in need of new therapies to reduce the burden of this disease. We are interested to see how this potential treatment performs in clinical trials in the future,” says Dr. James Kiley, director of NHLBI’s Division of Lung Diseases.

“The really exciting news is that amphotericin is a medicine that’s already approved and available on the market,” Burke notes.

This approach holds special promise for a subset of patients—about 10% of the people with cystic fibrosis—who do not respond to any treatment. However, more studies are needed before the drug could be safely used to treat cystic fibrosis in people.

If you or your child has been diagnosed with cystic fibrosis, it is important that you understand how cystic fibrosis can affect your health. You should also follow your treatment plan and see your doctor regularly.

How cystic fibrosis affects your health

Cystic fibrosis affects many parts and systems of the body. Complications will depend on the affected organs and the severity of disease.

Possible complications of cystic fibrosis include:

• Allergic bronchopulmonary aspergillosis (ABPA), which is an allergic reaction in the lungs to the fungus Aspergillus
• Bronchiectasis, a common complication of cystic fibrosis caused by long-term inflammation or obstruction of the airways
• cancer of the digestive tract, including the esophagus, stomach, small bowel, large bowel, liver, and pancreas
• Collapsed lung, called pneumothorax, resulting in air in the space between your lung and chest wall
• Diabetes due to damage to the pancreas, where insulin is made
• Fertility problems
• Gastrointestinal problems, such as distal intestinal obstruction syndrome (DIOS), in which your intestine becomes blocked by very thick intestinal contents
• Heart failure because of lung damage
• Hemoptysis, or coughing or spitting up of blood
• Kidney problems due to diabetes and some antibiotics, or kidney stones
• Liver disease or failure caused by blockage of the bile ducts in the liver, which may lead to cirrhosis and a need for a liver transplant
• Lung infections that may come back or be difficult to treat
• Malnutrition because the pancreas may not make enough enzymes to help digest and absorb nutrients from food
• Mental health problems, such as depression and anxiety
• Muscle and bone complications, including low bone density and osteoporosis, joint pain and arthritis, and muscle pains
• Pancreatitis and low levels of pancreatic enzymes leading to nutritional deficiencies, including low levels of vitamins A, D, E, and K
• Pulmonary exacerbations, which are episodes of worsening cough, shortness of breath, and mucus production caused by airway inflammation and blockage from an increase in bacteria in your airways and lungs
• Salt loss syndrome, in which your body quickly loses salt, or sodium and chloride, causing electrolyte and other imbalances
• Urinary incontinence, or loss of bladder control

Receive routine follow-up care

Regular checkups with your doctor may be part of your follow-up and treatment. How often your regular checkups take place will depend on your age. Younger patients, and those who have just been diagnosed, will have more frequent visits. As adults, you may see your doctor less often, perhaps every three months and then once a year for an evaluation.

Regular checkups may include:

• Education about airway clearance, infection control, energy, and nutrition goals
• Height and weight measurement, and calculation of BMI
• Physical activity guidance
• Physical exam, including examination of the heart, lungs, and abdomen to check the liver and for abdominal pain
• Physical therapy evaluation and needs
• Psychological assessment and support

Monitor your condition

In addition to more frequent regular checkups, you may need to see your doctor for other tests.

• Abdominal ultrasoundexternal link or a CT scan can look for the cause of abdominal pain, check the pancreas and liver, and look for distal intestinal obstruction.
• Blood tests check for diabetes; infection; liver disease; side effects of medicines, such as damage to kidneys; nutritional status, including complete blood count; and vitamin levels.
• Bone mineral density tests check for osteopenia or osteoporosis in those who are at risk. You may be at risk if you take corticosteroids long term, have severe lung disease, or do not get adequate nutrition. Testing of bone mineral density may be done with an X-ray test called a dual-energy X-ray absorptiometry (DEXA or DXA) scan.
• Lung imaging tests look for changes in lung function or lung infection. Early changes may be seen before you notice symptoms. In younger children, this may be done every other year to reduce radiation exposure.
• Glucose monitoring and testing check for cystic fibrosis–related diabetes.
• Pancreas function testing may include looking at an enzyme called pancreatic elastase-1 in your stool.
• Lung function tests include checking oxygen levels in your blood and spirometry, which is the most important and most widely used tool to assess lung function in cystic fibrosis. Regular spirometry is used to monitor lung function in people age 6 and older and may be done in children as young as age 3.
• Respiratory sample smear and culture involves taking airway secretion or mucus samples every three months to look for microorganisms in the respiratory tract and, if necessary, treat them.

Healthy lifestyle changes

Staying healthy is an extremely important part of cystic fibrosis care. Your medical team will work with you to develop a plan for lifestyle changes that can become part of your everyday life.

• Avoid tobacco smoke, including secondhand smoke.
• Be physically active to improve lung function. Physical activity helps with airway clearance and improves bone mineral density, muscle strength, flexibility, and posture. Before starting any exercise program, ask your doctor about what level of physical activity is right for you.
• Choose healthy foods to improve overall health. Healthy eating is also important for normal growth in children who have cystic fibrosis. You may need to increase your food or calorie intake by eating more foods or by eating high-energy foods. A high-sodium eating plan or supplementation with sodium may be recommended at times.