Cystic fibrosis Flashcards
Inheritance pattern
Autosomal recessive
Epidemiology
One of most common autosomal recessive conditions affecting Caucasians: 1:2000 live births
1:25 people carry a copy of the faulty gene
Are babies screened for CF in UK at birth?
Yes
Cause
Mutations in CF transmembrane conductance regulator (CFTR) gene on chromosome 7.
This is a Chloride channel (Cl-) and defect leads to a combination of defective chloride secretion and increased sodium absorption across airway epithelium.
Changes in the composition of airway surface liquid predispose the lung to chronic pulmonary infections and bronchiectasis.
Neonatal clinical features
Failure to thrive
Meconium ileus
Rectal prolapse
Children and young adults respiratory clinical features
Cough Wheeze Recurrent infections Bronchiectasis Pneumothorax Haemoptysis Respiratory failure Cor pulmonale
Children and young adults GI clinical features
Pancreatic insufficiency (DM, Steatorrhoea)
Distal intestinal obstruction syndrome
Gallstones
Cirrhosis
Children and young adults other/’non respiratory or GI’ clinical features
Male infertility Osteoporosis Arthritis Vasculitis Nasal polyps Sinusitis Hypertrophic pulmonary osteoarthropathy
Signs
Cyanosis
Finger clubbing
Bilateral coarse crackles
Diagnosis
Sweat test - Sodium and chloride concentrations >60mmol/L (Usually more chloride)
Genetics - screen for common CF mutations
Screening test for exocrine pancreatic dysfunction
Faecal elastase
Tests
Bloods Bacteriology (cough swab and sputum culture) Radiology Abdominal ultrasound Spirometry Biochemistry (faecal fat analysis) Aspergillus serology/skin test
What type of defect is CF on spirometry
Obstructive
Abdominal ultrasound: what to look for in CF
Fatty liver
Cirrhosis
Chronic pancreatitis
CXR of CY patient
Hyperinflation
Bronchiectasis
What Blood tests would you take
FBC U and Es LFT Clotting Vit A, D, E levels Annual glucose tolerance test
Management
Multidisciplinary Management of chest, GI tract Other: Treatment of CF related diabetes DEXA bone scan for osteoporosis and treatment Arthritis, sinusitis and vasculitis Fertility and genetic counselling
Management of advanced lung disease
Oxygen
Diuretics (cor pulmonale)
Non-invasive ventilation
Lung or heart/lung transplantation (post-transplant survival is 5 years)
Prognosis
Median survival around 41 years in UK
Baby born today would expect to live longer
Chest management
Physiotherapy (postural drainage, airway clearance)
Antibiotics for acute infective exacerbations
Chronic Pseudomonas is an important predictor of survival
Mucolytics may be useful e.g. DNase
Bronchodilators
Annual CXR surveillance recommended
GI management
Pancreatic enzyme replacement
Fat soluble vitamin replacement (ADEK)
Ursodeoxycholic acid for impaired liver function
Cirrhosis may require liver transplant
Mutation specific therapies for CF
Ivacaftor and Lumacaftor target the CFTR protein.
Ivacaftor is a CFTR potentiator and increases the open probability of CFTR channels
Lumacaftor is a CFTR corrector and increases amount of cell surface-localised protein
Microbiological diagnosis of CF
Sputum culture
