Cystic fibrosis - causes, symptoms, diagnosis, treatment, pathology

Other CF-Related Issues00:05:19

Other complications include infertility in men due to absent vas deferens, digital clubbing, nasal polyps, and allergic bronchopulmonary aspergillosis (ABPA), a hypersensitivity reaction to a fungus.

Introduction to Cystic Fibrosis00:00:18

Cystic fibrosis (CF) is a genetic disorder, primarily known for affecting the lungs but also impacting the pancreas significantly, leading to cysts and fibrosis. It's an autosomal recessive disorder caused by mutations in the CFTR gene, requiring two mutated genes for the disease to manifest. CFTR codes for a protein that secretes chloride ions, which draw water into secretions, thinning them out.

The ∆F508 Mutation and its Impact00:01:34

The most common mutation in CF is ∆F508, a deletion of the 508th amino acid, phenylalanine. This mutation causes the CFTR protein to misfold and prevents it from reaching the cell membrane, leading to a lack of chloride ion pumping. This results in overly thick secretions throughout the body.

Impact of CF on the Pancreas00:02:25

In newborns, thick secretions can cause meconium ileus. In early childhood, pancreatic insufficiency occurs because thick secretions block pancreatic ducts, preventing digestive enzymes from reaching the small intestine. This leads to malabsorption of fat and protein, poor weight gain, steatorrhea, and eventually, pancreatic damage, inflammation, and potentially insulin-dependent diabetes.

Impact of CF on the Lungs00:03:37

Lung problems typically emerge later in childhood. Thick mucus impairs mucociliary action, leading to chronic bacterial colonization. Increased bacterial load causes CF exacerbations, characterized by cough, fever, and decreased lung function, often requiring antibiotics. Persistent infections and inflammation can lead to bronchiectasis and, ultimately, respiratory failure, the primary cause of death in CF patients.

Diagnosis of Cystic Fibrosis00:05:52

Newborn screening detects high levels of immunoreactive trypsinogen (IRT). A sweat test confirming high chloride levels (due to CFTR dysfunction in sweat glands) is used for definitive diagnosis. Parents often notice their baby tastes salty.

Treatment of Cystic Fibrosis00:06:38

Treatment focuses on nutrition, including fat-soluble vitamins, extra calories, and pancreatic enzyme supplements. Pulmonary treatments involve chest physiotherapy, inhalers, and medications like N-acetylcysteine and dornase alfa to thin mucus. Lung transplants may be necessary for severe cases.

Emerging Personalized Treatments00:07:33

New personalized treatments target specific CFTR mutations. For instance, lumacaftor helps bring mutated ∆F508 CFTR to the cell membrane, often combined with ivacaftor, which improves CFTR function. These drugs, while not a cure, represent significant progress in personalized medicine, with future genetic technologies aiming to correct gene mutations directly.