cystic fibrosis

What Causes Cystic Fibrosis

This condition is caused by a mutation in the CFTR gene. The CFTR gene controls the movement of salt and water in and out of your cells. A defect in this gene causes the mucus to become thick and sticky.

• Cystic fibrosis is inherited through a recessive genetic pattern.
• If both parents carry the defective gene, there is a 25% chance of the child being affected.

Symptoms of Cystic Fibrosis

Symptoms can vary but often include:

• Persistent coughing, at times with phlegm.
• Frequent lung infections.
• Wheezing or shortness of breath.
• Poor growth or weight gain despite a good appetite.
• Difficulty in bowel movements.

Diagnosis and Testing for Cystic Fibrosis

CF is usually diagnosed through genetic testing and a sweat test, which measures the salt content in sweat. These tests can identify carriers of the CFTR gene mutation.

Cystic Fibrosis Genetic Mutations

The genetic basis of Cystic Fibrosis (CF) is rooted in mutations of the CFTR gene. Understanding these mutations helps in comprehending the disease's onset and variations.

Understanding CFTR Gene Mutations

The CFTR gene mutations vary widely but all affect the production or function of the CFTR protein. This gene provides the instructions for making a protein that functions as a channel through cell membranes, facilitating the transport of chloride ions.

• A defective chloride channel disrupts the salt balance in cells, leading to the build-up of thick mucus.
• Over 1,700 mutations in the CFTR gene have been identified related to CF, but not all cause severe disease.

Cystic Fibrosis Symptoms

Recognizing symptoms of Cystic Fibrosis (CF) early can aid in managing the condition effectively. Symptoms often manifest differently depending on age and individual health.

Respiratory Symptoms

Respiratory complications are the most prominent symptoms due to the thick and sticky mucus.

• Persistent cough: Often produces thick sputum.
• Frequent lung infections: Such as pneumonia or bronchitis.
• Wheezing: Similar to asthma symptoms.
• Shortness of breath: Especially during physical activity.

Digestive Symptoms

The digestive system can also be affected by CF, mainly due to blocked pancreatic ducts preventing enzyme flow.

• Poor growth: Despite a normal or increased appetite.
• Greasy, bulky stools: Due to malabsorption of nutrients.
• Constipation: Or intestinal blockage, known as meconium ileus in newborns.

Other Symptoms

Apart from respiratory and digestive symptoms, cystic fibrosis may also affect other bodily functions.

• Salty-tasting skin: Due to excess chloride on the skin surface.
• Delayed puberty: Common in teenagers with CF.
• Clubbing of fingers and toes: Enlargement or rounding of the fingertips.

Cystic Fibrosis Pathophysiology

The pathophysiology of Cystic Fibrosis (CF) involves complex interactions at the cellular level, primarily due to the malfunctioning CFTR protein.

Abnormal Mucus Secretion

In CF, the defective CFTR protein leads to improper chloride and sodium transportation across epithelial cells.

• This imbalance results in the production of thick and sticky mucus, obstructing airways and ducts.
• Mucus accumulation occurs primarily in the lungs and the digestive tract.

Infection and Inflammation

Thick mucus traps bacteria, leading to recurrent infections.

• Chronic infections promote persistent lung inflammation.
• Ongoing inflammation contributes to lung tissue damage and respiratory failure over time.

Pancreatic Dysfunction

The CFTR mutation affects the pancreas by obstructing ducts with thick secretions.

• This obstruction impairs pancreatic enzyme secretion, vital for digestion.
• Leads to nutrient malabsorption, particularly fats and fat-soluble vitamins (A, D, E, and K).

Sweat Gland Abnormalities

CF also affects sweat glands, leading to excess salt in sweat.

• This salt loss can cause an electrolyte imbalance, requiring careful management, especially during hot weather or vigorous exercise.

Cystic Fibrosis Treatment

Effective treatment for Cystic Fibrosis (CF) requires a comprehensive approach targeting symptom management and the underlying genetic cause.

Medication

Several medications are crucial in CF treatment:

• CFTR Modulators: These target malfunctioning CFTR proteins, improving their function. Common examples include ivacaftor and lumacaftor.
• Antibiotics: Used regularly to treat and prevent lung infections. They can be inhaled, oral, or intravenous.
• Mucolytics: Such as DNase (dornase alfa), help thin mucus, making it easier to clear from the lungs.
• Bronchodilators: Help open airways by relaxing the muscles around them, improving airflow and breathing.

Nutrition Support

Due to pancreatic insufficiency, individuals with CF need targeted nutrition strategies:

• Pancreatic Enzyme Supplements: Aide in the digestion and absorption of nutrients, taken with every meal and snack.
• High-Calorie Diet: Required to meet increased energy needs, often rich in protein and fat.
• Vitamin Supplements: Especially fat-soluble vitamins like A, D, E, and K, which are often poorly absorbed.

Physical Therapy

Physical activity plays a vital role in managing symptoms:

• Chest Physiotherapy (CPT): Performed daily to help loosen and clear mucus from the lungs.
• Exercise Programs: Enhance cardiovascular fitness, strengthen muscles, and contribute to improved lung function.

Surgical Interventions

Surgery is reserved for severe complications:

• Lung Transplant: Considered for end-stage lung disease, offering a chance for improved quality of life.
• Sinus Surgery: To remove nasal polyps that obstruct breathing.

Cystic Fibrosis Complications

Living with Cystic Fibrosis (CF) brings about various health complications, arising predominantly due to the chronic buildup of thick mucus in different organs.

Respiratory Complications

Respiratory issues are the most common complications observed in CF.

• Bronchiectasis: A condition where lung airways are irreversibly widened, causing difficulty in clearing mucus.
• Chronic Respiratory Infections: Continuous lung infections may lead to progressive lung damage.
• Pneumothorax: An abnormal presence of air between the lung and chest wall, causing lung collapse.

Digestive Complications

CF significantly impacts digestive processes, often due to obstruction of pancreatic ducts.

• Pancreatitis: Inflammation of the pancreas due to blocked enzyme flow.
• Intestinal Obstruction: Known as Distal Intestinal Obstruction Syndrome (DIOS), caused by thickened stools.
• Rectal Prolapse: Occurs when part of the rectum protrudes through the anus, often due to chronic constipation.

Reproductive Complications

Reproductive health can also be affected by CF, complicating fertility.

• Infertility in Males: Due to absent vas deferens, leading to obstructive azoospermia.
• Reduced Fertility in Females: Thick cervical mucus can obstruct sperm entry, and may also experience irregular menstrual cycles.

Liver Complications

Although less common, liver complications can occur due to mucus blocking bile ducts.

• Cirrhosis: Scarring of liver tissue, potentially leading to liver failure if untreated.
• Gallstones: More frequent in CF patients due to altered bile composition.