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Causes, Signs, Diagnosis and Treatment of Cystic Fibrosis

Cystic fibrosis is a genetic disorder of the secretory glands, including the glands that manufacture mucus and sweat. People with cystic fibrosis secrete mucus that is very viscous and sticky. It builds up in the lungs, blocking the airways and providing a home for bacteria. As a result, sufferers have trouble breathing and are prone to lung infections.

The mucus also blocks up the pancreatic ducts, which means that the digestive enzymes made by the pancreas don’t reach the small intestine. This results in vitamin deficiency and malnutrition because the body cannot absorb fats and proteins, and food passes through the body without being properly digested. It also causes other digestive problems such as constipation, gas, bloating, bulky stools and discomfort/pain.

It isn’t just mucosal secretions that are affected – the sweat also becomes extremely salty, so the sufferer loses large amounts of salt and experiences dehydration, fatigue, hypotension, heat stroke and increased heart rate. In extreme cases, they may even die.

Cystic fibrosis is a progressive disorder, which means that it gets worse over time. In the past, children with cystic fibrosis did not usually live to adulthood but nowadays, with improved drugs and medical care, the prognosis has improved so that nowadays, people with cystic fibrosis live into their forties, fifties or even longer.

Other Names for Cystic Fibrosis:

  • Mucoviscidosis
  • Mucoviscidosis of the pancreas
  • Pancreatic cystic fibrosis
  • Cystic fibrosis of the pancreas
  • Fibrocystic disease of the pancreas
  • Pancreas fibrocystic disease

Fast Facts about Cystic Fibrosis

  • Cystic fibrosis is a progressive genetic disorder that can affect men or women
  • In order for someone to be born with full-blown cystic fibrosis, both their parents must be carriers
  • The symptoms of cystic fibrosis can vary from one person to another
  • It affects the lungs, liver, pancreas, intestines, sinuses and sex organs
  • It makes the mucus viscous and sticky, causing blockages in the lungs and pancreas and leading (amongst other things) to breathing difficulties, increased likelihood of respiratory infection and digestive problems
  • People with cystic fibrosis have very salty sweat – this is often the first symptom that parents notice in babies who have the disease
  • There is no cure for cystic fibrosis, but its symptoms can be managed with the aid of drugs and lifestyle changes
  • Life expectancy for cystic fibrosis sufferers has improved as treatments have improved

Causes of Cystic Fibrosis

Cystic fibrosis is a genetic disorder caused by a defect in the CFTR (cystic fibrosis conductance transmembrane regulator) gene. This gene provides instructions to make chloride channels, which control the movement of chloride ions and water in and out of cells. Defects in the chloride channels are what cause the viscous mucus and extremely salty sweat.

There are over a thousand defects that are known to affect the CFTR gene, which is why the severity of cystic fibrosis can vary from person to person.

Risk Factors for Cystic Fibrosis

The CFTR gene is inherited via the autosomes (the non-sex determining chromosomes), so cystic fibrosis can affect both males and females. The gene is also recessive, which means that in order for a child to be born with full-blown cystic fibrosis, both parents must be cystic fibrosis carriers (i.e. they must themselves have one copy of the faulty CFTR gene). If a man and a woman who are both cystic fibrosis carriers have children, there is a one in four chance that their child will have full-blown cystic fibrosis, a one in two chance that their child will be a carrier, and a one in four chance that their child will not inherit either parent’s faulty CFTR gene. Many people do not know that they are cystic fibrosis carriers.

Cystic fibrosis can affect people of any ethnic or racial origin, although it is most common in people of Northern European stock. It occurs in 1 in 2,500 – 3,500 newborn Caucasian babies and is also relatively common in Latinos and American Indians.

Symptoms of Cystic Fibrosis

In babies with cystic fibrosis, the parents might first notice something is wrong when they kiss their child and find that the sweat tastes salty. Later on, the other symptoms of cystic fibrosis start to appear. The thick, sticky mucus associated with cystic fibrosis causes airway blockage and lung infections, often caused by unusual bacteria (e.g. mucoid Pseudomonas) that do not respond to conventional antibiotics. The sufferer may also have frequent attacks of bronchitis and pneumonia.

Other symptoms include dehydration, fatigue, hypotension (low blood pressure), weakness, heat stroke, increased heart rate, sinusitis (sinus infection), nasal polyps, and digestive problems caused by blockage in the pancreatic ducts. This blockage stops digestive enzymes from reaching the intestine, which means that the body cannot absorb food properly. As a result, the patient suffers from diarrhea, greasy or foul-smelling stools, constipation, gas, malnutrition, poor growth and slow weight gain.

Cystic fibrosis causes fertility problems in both male and female sufferers – most men with cystic fibrosis are infertile because the vas deferens (the tube that carries sperm from the testes to the penis) is not developed properly. Infertility also occurs in women with cystic fibrosis, although it is less common – female infertility may be due to mucus blockage in the cervix.

As the disease progresses, the sufferer will experience more serious problems such as pneumothorax, bronchiectasis, pancreatitis, rectal prolapse, liver disease (due to blockage or inflammation in the bile ducts), diabetes and gallstones. Low bone density, osteoporosis and clubbing (a widening and rounding of the tips of the fingers/toes) may also occur late in cystic fibrosis.

Diagnosing Cystic Fibrosis

It is possible to diagnose cystic fibrosis in the fetus during pregnancy, using chorionic villus sampling or amniocentesis.

Genetic tests will determine whether a newborn baby has faulty CFTR genes, and also what type of CFTR defect they have. A blood test can also be carried out; this shows whether the baby’s pancreas is functioning as it should.

If either the genetic or blood test indicates cystic fibrosis, the diagnosis can be confirmed using a sweat test that involves rubbing the skin with a sweat-inducing chemical and generating a mild electric current with an electrode, which also stimulates sweating. The sweat is then collected on paper or gauze, before being analysed for its salt content. High salt levels indicate the possibility of cystic fibrosis.

Treatment Options for Cystic Fibrosis

There is no actual cure for cystic fibrosis at present, so any treatments carried out are aimed at reducing the symptoms, and will involve a combination of drugs, exercise and diet. These treatments may include:

  • Specialized breathing techniques, aerobic exercise and CPT (chest physical therapy, also known as percussion or chest clapping). This involves pounding the chest and back repeatedly to loosen mucus and enable the patient to cough it up. CPT can either be done with the hands or with the aid of a device such as an electric chest clapper, inflatable therapy vest or a vibrating mask or hand-held device.
  • Antibiotics to prevent and treat lung infection – these are given orally or via inhalation or in the case of severe infections, intravenously. Other respiratory drugs used in cases of cystic fibrosis include bronchodilators (which widen the airways and help breathing), mucolytic (mucus-thinning) agents, and antiinflammatory agents to reduce swelling in the airways caused by infection. Advanced lung disease may require oxygen therapy or even a lung transplant.
  • Nutritional therapy to improve growth/development, help deal with digestive problems and improve resistance to infection. Nutritional therapy may include supplements of fat-soluble vitamins (A, D, E and K), salt supplements or a high salt diet, oral pancreatic enzymes and high-calorie shakes. A feeding tube inserted through the nose or a surgically-made hole in the stomach can be used at night to provide extra calories/nutrients.
  • Other digestive treatments including enemas and mucolytic agents for treating intestinal blockage.

Prevention of Cystic Fibrosis

If someone is born with cystic fibrosis, it is not possible to prevent the disease from developing. However, couples can have genetic counselling before they conceive a child, in order to find out whether both of them are cystic fibrosis carriers. This involves testing a sample of blood or saliva to detect faulty cystic fibrosis genes – such tests are 90 percent accurate.

Amniocentesis or chorionic villus sampling can also be carried out during pregnancy, to determine whether the fetus has the disease.

Antibiotics may be given to prevent lung infections, and bronchodilators can be given before CPT to help clear mucus out of the airways.

Lifestyle changes such as diet, exercise, physical chest therapy etc., will also help mitigate the symptoms.

Coping with Cystic Fibrosis

It is important to get specialized care for the disease. In the US, this is often obtainable at major medical centers or at one of more than a hundred CF Care Centers.

A broad program known as pulmonary rehabilitation (PR) will help improve your well-being. This includes nutritional and psychological counselling, exercise training, and education on how to manage the disease and conserve your energy. Psychological counselling and joining a support group can be a great help in adjusting to the disease.

Children with cystic fibrosis should be encouraged to learn as much as possible about the disease and how to manage it.

Eat a healthy diet and drink plenty of fluids. Take the dietary supplements recommended for cystic fibrosis.

Minimize the stress on your respiratory system – avoid secondary tobacco smoke (and don’t smoke yourself). Do regular CPT as recommended by your doctor.

Take precautions against infection by washing your hands often. Even if you are infertile as a result of cystic fibrosis, you should still have protected sex to avoid infection via STDs.

Where to Find More Information and Support:
Cystic Fibrosis Foundation
Cystic Fibrosis Trust