Cystic fibrosis

Overview: What is cystic fibrosis?

Cystic fibrosis is abbreviated internationally with the letters CF; in Germany this metabolic disease is also known as “mucoviscidosis”. If cystic fibrosis affects you, a relative, or a loved one, you or your loved one has a disorder of the mucus-producing glands. The cause is a defective gene inherited from both parents.

In cystic fibrosis, thick mucus forms, almost always affecting the lungs and often the pancreas and intestines. The typical symptoms of CF are therefore cough with viscous sputum, as well as abdominal pain and digestive problems. Even infants and young children with this metabolic disease have lung or intestinal symptoms.

Cystic fibrosis – incidence and age

Although cystic fibrosis is a rare disease overall, it is one of the most common inherited diseases: It is the most common genetic metabolic disease in Western Europe. About four percent of all people have a gene defect that allows them to inherit cystic fibrosis. However, this only happens if the second parent also passes on this change in inheritance. This is the case for one in about 2,700 newborns. In Switzerland, there are about a thousand people who suffer from CF. Among them, there are now more adults than children, which speaks for the good survival rate.

Cystic fibrosis only occurs when both parents have passed on a so-called CFTR gene that is affected by a mutation. Healthy people who have inherited a single altered CFTR gene do not develop cystic fibrosis, but they can pass on the predisposition to the disease to their children.

Only a few decades ago, the life expectancy of CF patients rarely went beyond the age of twenty. Today, thanks to modern treatment methods, many people suffering from cystic fibrosis live more than twice as long.

Cystic fibrosis: causes and risk factors

Strictly speaking, there is only one risk factor for cystic fibrosis: it consists of having two parents who both have a particular trait in their genetic makeup. This is a gene on chromosome number 7 that has been altered by mutation. This gene is called the CFTR gene. It regulates the production of a protein called “Cystic Fibrosis Transmembrane Conductance Regulator”, or CFTR for short.

The CFTR protein ensures that salts (chloride ions) are transported smoothly between the inner and outer space of the body cells. However, the gene defect disrupts this transport. This leads to dehydration of the cells and, in certain organs, to the formation of viscous secretions (e.g. viscous mucus in the respiratory tract, digestive organs, etc). The lungs and pancreas are particularly affected.

Symptoms: cystic fibrosis

If you (or your child) suffer from cystic fibrosis, viscous mucus has accumulated in the lungs. The fine cilia of the bronchial tubes find it difficult to transport this tough mucus upwards to the throat. This has tangible consequences:

• The airways narrow (e.g. due to mucus obstruction), breathing becomes difficult.
• Since bacteria contained in the mucus can only be coughed up insufficiently, infections of the respiratory tract easily develop. Coughing, increasing shortness of breath and inflammation of the sinuses occur.

When cystic fibrosis is diagnosed, there is a very high likelihood that viscous mucus will block the fine ducts of the pancreas. Therefore, it can only insufficiently produce and transport digestive enzymes. Possible consequences are:

• Abdominal pain
• Bloating
• Diarrhea
• Pathological increase of the fat content in the stool
• Weight loss or no weight gain
• If less insulin is produced: Diabetes (diabetes)
• Newborns at risk of intestinal obstruction

In men affected by cystic fibrosis, viscous mucus can block the vas deferens. The result is infertility. In women, mucus often accumulates in the fallopian tubes, which also leads to infertility.

Cystic fibrosis: diagnosis with us

If we suspect cystic fibrosis, we can confirm our diagnosis with various tests.

• The sweat test analyzes the salt content of skin sweat. If the excreted sweat contains an above-average amount of salt (more than 60 millimoles per liter), this is a clear indication of cystic fibrosis (CF). In healthy people, the value is less than 30 millimoles per liter, so it is not even half as high.
• The meconium test provides evidence of cystic fibrosis in newborns. Meconium (or infantile sputum) is the medical term for the first stool a baby excretes. If there is an increased number of special proteins (proteins) in it, this is an indication of CF.The trypsinogen test (immunoreactive trypsinogen test, IRT test) is a blood test with which we measure the concentration of trypsinogen in the blood. Trypsinogen is the precursor of a digestive enzyme. In the neonatal period, an elevated test result may be considered indicative of CF, so another test is used to confirm CF.
• DNA analysis reliably shows whether cystic fibrosis is present by detecting the underlying gene alteration. This genetic Test1 also has an influence on the choice of therapy in the further course.

Further examinations should clarify whether organs have already been damaged by the cystic fibrosis. This is done with ultrasound of the abdomen, lung function tests and X-ray examinations, among other things. An examination of the coughed-up mucus (called sputum) will determine if the lungs are affected by disease-causing bacteria.

Cystic fibrosis: prevention, early detection, prognosis

Since cystic fibrosis is a hereditary disease, it cannot be prevented by preventive measures. If there are known cases of cystic fibrosis (CF, cystic fibrosis) in your family, you can get information and advice at a genetic counseling center. Doctors who specialize in medical genetics work here. You can find out more, for example, from the Swiss Society for Medical Genetics (SGMG).

Cystic fibrosis can be detected even before birth. Experts refer to this as prenatal diagnostics (pre-natal diagnostics). One method we use for this is called amniocentesis. During amniocentesis, we remove amniotic fluid from the amniotic sac of the pregnant woman. Subsequently, the cells of the unborn child obtained in this way are examined in the laboratory to determine whether they contain genetic changes that are typical of cystic fibrosis. Instead of amniotic fluid, a sample of the placenta can also be taken. This procedure is called chorionic villus sampling .

Switzerland introduced national screening for newborns to detect cystic fibrosis on January 1, 2011. If the disease is diagnosed early, it improves its prognosis because complementary diagnostics and therapies are then possible at an early stage.

Course and prognosis of cystic fibrosis

The average course of cystic fibrosis and its prognosis have improved significantly over the past decades and years. This is due to advances in the treatment of this hereditary disease. In 1980, less than two percent of CF patients came of age; today, more than 50 percent do. Today, a baby diagnosed with cystic fibrosis shortly after birth has a good chance of living to at least 50 years of age.

As a result of cystic fibrosis, the function of the pancreas may also be impaired. This is because the function of the pancreas is disturbed by the viscous mucus and the digestive enzymes (enzymes) no longer reach the intestine. Enzymes are important for digestion and nutrient absorption. Without effective medical treatment (enzyme replacement), malnutrition and growth failure may result.

Cystic fibrosis: effective treatment

• Treatments are linked
• Link to LuTPL as a possible therapy

In case of a surgical intervention, the Institute of Anesthesiology will select the anesthesia procedure that is individually adapted to you.