- Cystic fibrosis (CF) is a chronic, genetic disorder that primarily affects the lungs, digestive system, and other organs by disrupting the normal function of exocrine glands.
- It is caused by mutations in the CFTR gene (Cystic Fibrosis Transmembrane Conductance Regulator), which codes for a protein that regulates the movement of salt and water across epithelial cell membranes. When this protein is defective or absent, it leads to the production of thick, sticky mucus that clogs airways and ducts, causing persistent infections and organ damage over time.
- CF is inherited in an autosomal recessive pattern, meaning a person must inherit two defective copies of the CFTR gene—one from each parent—to develop the disease. It is one of the most common life-shortening genetic diseases in people of European descent, with varying prevalence in other ethnic groups. Advances in newborn screening have allowed for earlier diagnosis, often within the first few weeks of life.
- The pulmonary system is most critically affected. Thick mucus accumulates in the airways, leading to chronic cough, wheezing, frequent lung infections, and progressive lung damage. Recurrent infections, often caused by bacteria such as Pseudomonas aeruginosa or Staphylococcus aureus, result in inflammation, bronchiectasis, and eventually respiratory failure if untreated. Respiratory symptoms are the main cause of morbidity and mortality in CF patients.
- The digestive system is also significantly impacted. The thickened secretions block the pancreatic ducts, preventing digestive enzymes from reaching the intestines. This leads to malabsorption of fats, proteins, and fat-soluble vitamins (A, D, E, and K), resulting in poor weight gain, steatorrhea (fatty stools), vitamin deficiencies, and failure to thrive, particularly in children. CF can also cause liver disease, intestinal blockages, and CF-related diabetes due to pancreatic damage over time.
- Diagnosis of cystic fibrosis typically involves a combination of tests, including a sweat chloride test (the gold standard), which measures the concentration of chloride in sweat—elevated levels are a hallmark of the disease. Genetic testing can confirm mutations in the CFTR gene. Lung function tests, imaging studies, and stool analysis may also be used to assess the extent of organ involvement.
- There is no cure for cystic fibrosis, but treatment has advanced dramatically in recent years. Management is highly individualized and multidisciplinary, aiming to control symptoms, prevent complications, and improve quality of life. Common interventions include airway clearance techniques, inhaled medications (like bronchodilators, mucolytics, and antibiotics), pancreatic enzyme replacement therapy (PERT), nutritional support, and vitamin supplementation. In advanced cases, lung transplantation may be considered.
- A breakthrough in CF treatment came with the development of CFTR modulators—targeted drugs that improve the function of the defective CFTR protein in certain genetic subtypes. Medications such as ivacaftor, lumacaftor/ivacaftor, tezacaftor/ivacaftor, and elexacaftor/tezacaftor/ivacaftor (marketed as Trikafta) have shown significant benefits in improving lung function, reducing hospitalizations, and enhancing overall health and survival.
