Cystic Fibrosis – Causes, Symptoms, Diagnosis, Treatment

Cystic Fibrosis

Cystic fibrosis (CF) is a genetic disorder that affects mostly the lungs, but also the pancreas, liver, kidneys, and intestine. Long-term issues include difficulty breathing and coughing up mucus as a result of frequent lung infections. Other signs and symptoms may include sinus infections, poor growth, fatty stool, clubbing of the fingers and toes, and infertility in most males. Different people may have different degrees of symptoms.

Other Names of Cystic Fibrosis

  • Cystic fibrosis of the pancreas
  • Fibrocystic disease of the pancreas
  • Mucoviscidosis (MU-ko-vis-ih-DO-sis)
  • Mucoviscidosis of the pancreas
  • Pancreas fibrocystic disease
  • Pancreatic cystic fibrosis

Parts of the Body Does Cystic Fibrosis Affect

The disease also affects the following organs

Pancreas 

The thick mucus caused by CF blocks ducts in your pancreas. This stops digestive enzymes (proteins that break down your food) from reaching your intestine. As a result, your body has a hard time absorbing the nutrients it needs. Over time, this can also lead to diabetes.

Liver

If the tubes that remove bile become clogged, your liver gets inflamed and severe scarring (cirrhosis) occurs.

Small intestine

Because breaking down high-acid foods that come from the stomach is a challenge, the lining of the small intestine can erode.

Large intestine

Thick secretions (liquids) in your stomach can make feces (poop) very thick. This can cause blockages. In some cases, the intestine may also start to fold in on itself like an accordion (called “intussusception”).

Bladder 

Chronic coughing weakens the bladder muscles. Almost 65% of women with CF have what’s called “stress incontinence.” This means that you leak urine when you cough, sneeze, laugh, or lift something. Though more common in women, men can have it, too.

Kidneys

Some people with CF get kidney stones. These small, hard mineral deposits can cause nausea, vomiting, and pain. If ignored, they can lead to a kidney infection.

Reproductive organs

Excess mucus affects fertility in both men and women. Most men with CF have problems with the tubes that transport their sperm, or what’s called the “vasa deferentia.” Women with CF have very thick cervical mucus, which can make it harder for a sperm to fertilize an egg.

Other parts of the body

CF can also lead to thinning of the bones (osteoporosis) and muscle weakness. Because it upsets the balance of minerals in the blood, it can also bring about low blood pressure, fatigue, a fast heart rate, and a general feeling of weakness.

Causes of Cystic Fibrosis

Cystic fibrosis is caused by a gene defect. (CFTR gene: cystic fibrosis transmembrane regulator). This gene is responsible for a protein that regulates the transportation of salt and water into and out of cells. The gene defect leads to the build-up of viscous, high-protein mucus in the glands and very salty sweat.

Hereditary

Statistically speaking, one of twenty people carry the defective gene responsible for causing cystic fibrosis without falling victim to it themselves. Only in case where both parents carry the defective gene is it possible for the disease to develop in their children.

Symptoms of Cystic Fibrosis

CF is a multi-system disorder that produces a variety of symptoms including:

Respiratory symptoms 

  • The viscous mucus causes chronic coughing and regular infections of the respiratory organs with germs such as staphylococcus aureus and pseudomonas aeruginosa. Chronic infections may result in the development of pulmonary insufficiency in the course of the disease, causing shortness of breath and oxygen deficiency.
  • Sinusitis is an infection that often occurs in cases of cystic fibrosis. The growth of polyps in the paranasal sinuses may lead to nasal obstruction and an impaired sense of taste.
  • A persistent cough that produces thick mucus (sputum)
  • Wheezing
  • Breathlessness
  • Exercise intolerance
  • Repeated lung infections
  • Inflamed nasal passages or a stuffy nose

Digestive symptoms

  • The pancreas does not produce enough enzymes to break down food, having a significant impact on the body’s ability to absorb fat and protein. This leads to problems with digestion (e.g. diarrhea, fatty stools) and to malnutrition.
  • Children do not grow properly and do not gain sufficient weight.
  • In rare cases, newborns may be afflicted by intestinal blockage (meconium ileus).
  • Diabetes and liver dysfunction (such as jaundice) may also occur as a result of cystic fibrosis.
  • Foul-smelling, greasy stools
  • Poor weight gain and growth
  • Intestinal blockage, particularly in newborns (meconium ileus)
  • Severe constipation

Diagnosis of Cystic Fibrosis

If you or your child has CF, your doctor may recommend other tests, such as:

  • Genetic tests to find out what type of CFTR defect is causing your CF.
  • Lung function tests – These tests measure how much air you can breathe in and out, how fast you can breathe air out, and how well your lungs deliver oxygen to your blood.
  • Newborn screening—A health care provider takes a few drops of blood from a heel prick, usually while the newborn is in the hospital. The provider places the drops of blood on a special card known as a Guthrie card. Tests at a laboratory can diagnose conditions including CF. All states in the U.S. require the testing of newborns at birth as well as a few weeks later.
  • Sweat test—This is the most conclusive testing for CF. Sweat tests measure the amount of chloride in the body’s sweat, which is elevated in people with CF. People of any age can have a sweat test. In the test, a health care provider applies a chemical called pilocaprine to the skin.
  • A sputum culture – For this test, your doctor will take a sample of your sputum (spit) to see whether bacteria are growing in it. If you have bacteria called mucoid Pseudomonas, you may have more advanced CF that needs aggressive treatment.
  • CF Mutation Panel – (American Association for Clinical Chemistry)
  • Genetic tests – These are performed using a blood sample that is tested for the faulty genes that cause CF.
  • Chest X-rays – X-rays of the chest are used to support or confirm CF if a health care provider suspects that a person has the disease. Other forms of testing need to be used to confirm the presence of CF.
  • Sinus X-rays – As with chest X-rays, sinus X-rays can confirm CF in patients showing certain symptoms of CF. Other forms of testing are used along with sinus X-rays.
  • Lung function tests – The most common lung function test uses a device called a spirometer. The patient breathes in completely. He or she then empties the inhaled breath into the mouthpiece of the spirometer.
  • A sputum culture – A health care provider takes a sample of a patient’s sputum (spit) and tests it for bacteria. Certain bacteria, such as pseudomonas, are most commonly found in people with CF.
  • Chymotrypsin Test (American Association for Clinical Chemistry)
  • Cystic Fibrosis (CF) Respiratory Screen – Sputum (Nemours Foundation)
  • Cystic Fibrosis (CF) – Chloride Sweat Test (Nemours Foundation)Also in Spanish
  • Cystic Fibrosis – Prenatal Screening and Diagnosis(American College of Obstetricians and Gynecologists)Also in Spanish
  • Newborn Screening for CF (Cystic Fibrosis Foundation)
  • Trypsinogen Test (American Association for Clinical Chemistry)

Prenatal Screening

If you’re pregnant, prenatal genetic tests can show whether your fetus has CF. These tests include amniocentesis(AM-ne-o-sen-TE-sis) and chorionic villus (ko-re-ON-ik VIL-us) sampling (CVS).In amniocentesis, your doctor inserts a hollow needle through your abdominal wall into your uterus. He or she removes a small amount of fluid from the sac around the baby. The fluid is tested to see whether both of the baby’s CFTR genes are normal.In CVS, your doctor threads a thin tube through the vagina and cervix to the placenta. The doctor removes a tissue sample from the placenta using gentle suction. The sample is tested to see whether the baby has CF.

Cystic Fibrosis Carrier Testing

People who have one normal CFTR gene and one faulty CFTR gene are CF carriers. CF carriers usually have no symptoms of CF and live normal lives. However, carriers can pass faulty CFTR genes on to their children.If you have a family history of CF or a partner who has CF (or a family history of it) and you’re planning a pregnancy, you may want to find out whether you’re a CF carrier.

Treatment of Cystic Fibrosis

Medicines to treat infections

Medicines to open airways in the lungs or keep them open

  • Bronchodilators (such as albuterol or salmeterol), which are used to make breathing easier. They may also make it easier to cough up mucus.

  • Anticholinergics (such as Atrovent)

Medicines to control the amount and thickness of mucus

  • DNase (such as Pulmozyme) – It is used to thin mucus in the lungs.
  • Mucolytics (such as acetylcysteine) – to thin mucus in the lungs and the intestines. These aren’t used very much, though, because they can irritate the lungs.
  • Saltwater solution (hypertonic saline) – This is sometimes used to help clear mucus from the lungs. It is low-cost, and it may help reduce inflammation in the airways.

Medicines to reduce inflammation

Medicines to replace the effect of digestive enzymes

  • Enzyme replacement therapy (such as Creon or Pancreaze)
  • A small number of people with cystic fibrosis have a certain changed (mutated) gene called the G551D mutation.
  • If you have this changed gene and you are age 6 or older, the medicine ivacaftor (Kalydeco) can target the genetic cause of your lung problems and may help improve lung function.

Pulmonary rehabilitation

Your doctor may recommend a long-term program that may improve your lung function and overall well-being. Pulmonary rehabilitation is usually done on an outpatient basis and may include

Surgery of Cystic Fibrosis

  • Nasal polyp removal – Your doctor may recommend surgery to remove nasal polyps that obstruct breathing.
  • Oxygen therapy – If your blood oxygen level declines, your doctor may recommend that you breathe pure oxygen to prevent high blood pressure in the lungs (pulmonary hypertension).
  • Endoscopy and lavage – Mucus may be suctioned from obstructed airways through an endoscope.
  • Feeding tube – Cystic fibrosis interferes with digestion, so you can’t absorb nutrients from food very well. Your doctor may suggest temporarily using a feeding tube to deliver extra nutrition while you sleep. This tube may be inserted in your nose and guided to your stomach, or it may be surgically implanted into the abdomen.
  • Bowel surgery – If a blockage develops in your bowel, you may need surgery to remove it. Intussusception, where a section of bowel has folded in on itself, also may require surgical repair.
  • Lung transplant – If you have severe breathing problems, life-threatening lung complications or increasing resistance to antibiotics used to treat lung infections, lung transplantation may be an option. Because bacteria line the airways in diseases that cause permanent widening of the large airways (bronchiectasis), such as cystic fibrosis, both lungs need to be replaced.

Complications of Cystic Fibrosis

Respiratory system complications
  • Damaged airways (bronchiectasis) – Cystic fibrosis is one of the leading causes of bronchiectasis, a condition that damages the airways. This makes it harder to move air in and out of the lungs and clear mucus from the airways (bronchial tubes).
  • Chronic infections – Thick mucus in the lungs and sinuses provides an ideal breeding ground for bacteria and fungi. People with cystic fibrosis may often have sinus infections, bronchitis or pneumonia.
  • Growths in the nose (nasal polyps) – Because the lining inside the nose is inflamed and swollen, it can develop soft, fleshy growths (polyps).
  • Coughing up blood (hemoptysis) – Over time, cystic fibrosis can cause thinning of the airway walls. As a result, teenagers and adults with cystic fibrosis may cough up blood.
  • Pneumothorax – This condition, in which air collects in the space that separates the lungs from the chest wall, also is more common in older people with cystic fibrosis. Pneumothorax can cause chest pain and breathlessness.
  • Respiratory failure – Over time, cystic fibrosis can damage lung tissue so badly that it no longer works. Lung function usually worsens gradually, and it eventually can become life-threatening.
  • Acute exacerbations – People with cystic fibrosis may experience worsening of their respiratory symptoms, such as coughing and shortness of breath, for several days to weeks. This is called an acute exacerbation and requires treatment in the hospital.
  • Nutritional deficiencies – Thick mucus can block the tubes that carry digestive enzymes from your pancreas to your intestines. Without these enzymes, your body can’t absorb protein, fats or fat-soluble vitamins.
  • Diabetes – The pancreas produces insulin, which your body needs to use sugar. Cystic fibrosis increases the risk of diabetes. Around 30 percent of people with cystic fibrosis develop diabetes by age 30.
  • Blocked bile duct – The tube that carries bile from your liver and gallbladder to your small intestine may become blocked and inflamed, leading to liver problems and sometimes gallstones.
  • Intestinal obstruction – Intestinal obstruction can happen to people with cystic fibrosis at all ages. Children and adults with cystic fibrosis are more likely than are infants to develop intussusception, a condition in which a section of the intestines folds in on itself like an accordion.
  • Distal intestinal obstruction syndrome (DIOS) – DIOS is partial or complete obstruction where the small intestine meets the large intestine.
  • Reproductive system complications – Almost all men with cystic fibrosis are infertile because the tube that connects the testes and prostate gland (vas deferens) is either blocked with mucus or missing entirely. Certain fertility treatments and surgical procedures sometimes make it possible for men with cystic fibrosis to become biological fathers.
  • Thinning of the bones (osteoporosis) – People with cystic fibrosis are at higher risk of developing a dangerous thinning of bones.
  • Electrolyte imbalances and dehydration – Because people with cystic fibrosis have saltier sweat, the balance of minerals in their blood may be upset. Signs and symptoms include increased heart rate, fatigue, weakness and low blood pressure.

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