6- CF

• Cystic fibrosis

  Autosomal recessive life-limiting disease
• Cystic fibrosis

  • Genetic mutation of CFTR on chromosome 7 (a chloride channel and regulatory protein found in epithelial cell membranes in the lungs, pancreas, GI & reproductive tract)
  • Abnormal ion transport across epithelial cells
  • Increased salt content in sweat gland secretions, alteration in viscosity, & tenacity of mucus
• Cystic fibrosis presentation

  1. Decreased airway surface liquid layer

  2. Impaired ciliary function

  3. Retention of mucopurulent secretions

  4. Mucus stasis & airway inflammation

  5. Recurrent chest infections
• Recurrent chest infections in cystic fibrosis

  • Staph aureus (below 10 years of age)
  • Pseudomonas (after 10 years of age)
• Cystic fibrosis presentation

  • Damage to bronchial wall
  • Bronchiectasis
  • Abscess formation
• Cystic fibrosis presentation

  • Clubbing
  • Hyperinflated lung
  • Coarse inspiratory crackles
  • Expiratory wheeze
• Cystic fibrosis presentation

  • Small bowel obstruction
  • Meconium ileus (children)
  • Distal intestinal obstruction syndrome (adults)
• Cystic fibrosis presentation

  • Pancreatic exocrine insufficiency (lipase, amylase, protease)
  • Vitamin ADEK malabsorption
  • Steatorrhea
• Cystic fibrosis presentation

  • Failure to thrive in infancy
  • Low BMI
• Cystic fibrosis diagnosis

  1. Sweat test> Increased chloride concentration (≥ 60 mmol/L is diagnostic)

  2. Neonatal heel prick screening at birth (measure immunoreactive trypsinogens)

  3. Confirmatory genetic testing
• Cystic fibrosis treatment

  1. Multidisciplinary team

  2. Follow-up every 3 months (record FEV1 & BMI)
• Chronic pulmonary treatment for cystic fibrosis

  • Airway clearance technique
  • Long-term azithromycin (immunomodulatory, ↓ exacerbation frequency)
  • Nebulized therapy: Recombinant human DNase (improves FEV1 & survival), Hypertonic saline (↑ mucus clearance), Inhaled mannitol (↑ mucus clearance), Long-term antipseudomonal suppression therapy (inhaled tobramycin): ↓ respiratory decline and exacerbations
• Treatment of infections in cystic fibrosis

  1. Pseudomonas: combination of B-lactam (ceftazidime) & aminoglycoside (tobramycin)

  2. In exacerbations IV antibiotic therapy is based on previous history
• Nutrition treatment for cystic fibrosis

  • Increase caloric intake 150%
  • Fat soluble vitamin replacement (ADEK)
  • Overnight feeding via gastrotomy
  • Pancreatic enzyme replacement therapy
• Vaccinations (influenza, pneumococcal) for cystic fibrosis
• Respiratory failure in cystic fibrosis

  • Treated with oxygen and non-invasive ventilation
• Cystic fibrosis

  • Referred for lung transplant if FEV1 30% predicted
• CFTR modulating genetic therapy: Ivacaftor


  • For pts with G551D mutation (class 3 gating defect)
  • Improves CFTR function
• Respiratory complications of cystic fibrosis

  • Recurrent infections
  • Chronic daily cough and sputum
  • SOB
  • Hemoptysis (may be massive)
  • Recurrent sinusitis & Nasal polyps
  • Pneumothorax
  • Respiratory failure (95% die of respiratory failure)
  • Cor pulmonale
• Gastrointestinal complications of cystic fibrosis


  • Cirrhosis/portal HTN/hepatomegaly/abnormal LFTs (liver disease in 20%)
  • Distal intestinal obstruction syndrome (give oral laxatives)
  • Increased risk of gastrointestinal malignancy
• Infertility in cystic fibrosis

  • Male: 95% azoospermia, 20% absence of vas deferens
  • Female: thick cervical mucus blocks sperm entry
• Cystic fibrosis-related diabetes (in 40-50% of older adults)
• Kidney stones (calcium stones) in cystic fibrosis
• Osteoporosis & arthropathy in cystic fibrosis