Cystic Fibrosis: What It Is, Causes, Symptoms, and Treatment

Cystic fibrosis is a significant genetic disease that affects various organ systems, primarily the lungs and digestive system. During this condition, the body produces thick and sticky mucus. Over time, the mucus accumulates in the lungs and pancreatic ducts, causing blockages. Individuals with this condition, which can have a life-threatening course, generally have a shorter lifespan compared to healthy individuals. Until about 60-70 years ago, patients with cystic fibrosis only lived up to elementary school age. However, thanks to recent developments, individuals with this condition can now live into their 30s, 40s, and even beyond. The prevalence of cystic fibrosis in the population is approximately 1 in 3,000, and since 75% of newly diagnosed individuals are under the age of 2, it is important to raise awareness. Before answering frequently asked questions such as "What causes cystic fibrosis?" and "How is cystic fibrosis diagnosed?", it is important to first answer the question, "What is cystic fibrosis?"

What is Cystic Fibrosis?

Cystic fibrosis is a serious genetic disease that causes severe damage to the respiratory system and digestive tract. This damage is due to the accumulation of thick and sticky mucus in various organs. The organs most affected by this condition are the lungs, pancreas, liver, and intestines.

In this condition, the cells responsible for producing sweat, mucus, and digestive enzymes are affected. Normally, these secretions are thin and fluid, which helps keep various organs and tissues moist, preventing excessive dryness or damage from infections. However, in individuals with cystic fibrosis, due to faulty gene sequencing, the secretions are thick and viscous. Instead of moisturizing tissues, these thick secretions cause blockages in ducts, tubes, and various passageways. Over time, these blockages can lead to infections, respiratory failure, or deficiencies in essential nutrients, which negatively affect the overall well-being of the individual. Therefore, treatment for cystic fibrosis should begin as soon as the diagnosis is made. Early diagnosis and treatment are essential approaches to extending the quality and length of life for these individuals.

What Causes Cystic Fibrosis?

Cystic fibrosis is caused by a defect or mutation in the "Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene." This genetic change alters the secretion of salts both inside and outside of the cells. The altered salt secretion leads to the production of thick and sticky mucus in the digestive system, airways, and reproductive ducts. Additionally, there is an increase in the amount of salt excreted in the individual's sweat.

Mutations in the CFTR gene can occur in many forms. The type of mutation also determines the severity of the disease. Located on chromosome 7, this gene plays a role in the synthesis of proteins related to chloride channels. Approximately 2,000 different mutations in this gene region on chromosome 7 have been identified, which can result in cystic fibrosis. These mutations can be classified into five main categories: defective protein synthesis, defects in protein processing, problems related to gene regulation, issues with chloride channel functions, and problems with channel regulation.

For any child to have cystic fibrosis, they must inherit the faulty gene from both the mother and the father. If the child inherits only one mutation from either parent, they will be a carrier of cystic fibrosis. Since cystic fibrosis is a genetic condition, a positive family history and consanguineous marriages are significant risk factors.

What are the Symptoms of Cystic Fibrosis?

The symptoms of cystic fibrosis can vary from patient to patient and depend on the severity of the disease. The patient's age is also a significant factor in the diversity of symptoms. In some patients, the symptoms may appear during infancy, while in others, no symptoms may appear until adolescence. Over time, individuals with the disease may experience either improvement or worsening of their symptoms.

The primary symptom of cystic fibrosis is that the patient’s skin has a very salty taste. Some parents may easily feel this strong salty taste when they kiss their child. Other symptoms that may develop during the course of the disease vary depending on which organ system is affected.

If the thick and sticky mucus blocks the airways in the lungs, it can cause symptoms such as wheezing, coughing with mucus, shortness of breath during exercise, frequent respiratory infections, or nasal and sinus congestion. The abnormal thickness of the mucus not only affects the lungs but can also negatively affect the digestive system. If the channels responsible for enzyme flow from the pancreas to the small intestine are blocked, the intestines cannot absorb nutrients from the consumed food. This condition can lead to symptoms such as fatty and foul-smelling stools, constipation, nausea, bloating, loss of appetite, poor weight gain, and growth retardation. This is how the question "What are the symptoms of cystic fibrosis?" can be answered.

How is Cystic Fibrosis Diagnosed?

The diagnostic approach to cystic fibrosis starts with a sweat test, which analyzes the chloride level in the sweat. In some individuals, despite the presence of symptoms, a negative sweat test does not rule out the disease, and the situation is investigated further with repeated sweat tests. If the sweat test results are abnormal, the patient's DNA is analyzed to identify the presence of a genetic defect. The sweat test is the most commonly used test for diagnosing cystic fibrosis. In this test, sweat is collected using a pad or a tissue to examine the levels of electrolytes in the sweat. For example, if the salt levels are higher than normal, this would suggest cystic fibrosis. Other methods that can be used to diagnose cystic fibrosis include:

Immunoreactive Trypsinogen Test (IRT)
Cystic fibrosis is commonly seen in our country, and to make an early diagnosis and start treatment early, the IRT test has been added to newborn screening. For patients with high IRT values, a sweat test is performed for secondary confirmation of the diagnosis.

With the IRT test, abnormal protein levels in the blood of newborn babies can be detected. If the test result is higher than normal, it is considered a sign in favor of cystic fibrosis, but it must be confirmed with other tests.

For patients suspected of having cystic fibrosis, further tests are planned based on the affected organ.

How is Cystic Fibrosis Treated?

The treatment approach for cystic fibrosis, which can affect many organ systems, is planned to aim at improving the patient's quality of life and extending their lifespan. Therefore, it is crucial to control the symptoms caused by the disease. Basic interventions include protecting the respiratory system from infection, preventing possible blockages, and preserving lung function. In addition to protecting the respiratory system, supporting the digestive system with pancreatic enzymes and multivitamin supplements is also essential.

Antibiotics, mucus-thinning medications, nonsteroidal anti-inflammatory drugs, bronchodilators (airway dilators), and CFTR modulator therapies are some of the medications used in the treatment of this disease. In addition to medication, surgical treatment methods such as intestinal surgeries, tube feeding, and lung transplantation may also be considered for some patients.