Paediatric Cystic Fibrosis Flashcards
What kind of inheritance is CF?
Autosomal recessive
What is the gene prevalence of CF?
1 in 25
What is the disease prevalence of CF?
1 in 2500
What gene is responsible for the mutation causing CF?
CFTR: Cystic Fibrosis Transmembrane conductance Regulator
What is the most common mutation in Northern Europeans?
phe508del
What are the different classes of CFTR mutations?
- Normal
- Class 1: no synthesis
- Class 2: no maturation
- Class 3: blocked regulation
- Class4: decreased conductance
- Class 5: decreased abundance
What is the function of CFTR?
- Active transport channel for chloride
- Regulates liquid volume on epithelial surface
- Reduced chloride efflux
- Increased sodium influx via ENaC
What is abnormal ciliary function?
Collapse of cilia with excessive inflammation
How is neonatal screening carried out?
-Newborn bloodspot on day 5 called Guthrie test
Initial screen for immuno-reactive trypsinogen
-If positive then mutation analysis is performed
If a newborn screens positive then what are they referred for?
Sweat test
What correlations do studies show between screening and CF prognosis?
- Probably reduced infant mortality
- Better lung function
- Benefit in nutrition
How is CF managed?
- Specialist multi-disciplinary team
- Shared care with local clinics
- Surveillance in primary care
- Early treatment of infection
What are the 2 cardinal features of CF?
- Pancreatic insufficiency
- Recurrent bronchopulmonary infection
What can pancreatic insufficiency result in?
Abnormal stools -Pale or orange -Very offensive -Greasy or oily Failure to thrive -May thrive quite well on breast milk -May have defiences of fat soluble vitamins
How is pancreatic insufficiency treated?
- Enteric coated enzyme pellets
- High energy diet
- Fat-soluble vitamin and mineral supplements
- H2 antagonist or proton pump inhibitors
What lung conditions are those with CF prone to?
- Pneumonitis
- Bronchiectasis
- Scarring
- Abscesses
How are respiratory infections prevented in early years?
- Segregation/ cohorting to prevent cross-infection
- Airway clearance and adjuncts
- Mucolytics
- Prophylactic antibiotics
- Annual influenza vaccination
What are the respiratory pathogens in CF?
- Staph aureus
- Haemophilus influenzae
- Pseudomonas aeroginosa
What other pathogens are less common?
- Burkholderia cepacia
- Stenotrophomonas maltophilia
- Alcaligenes xylosoxidans
- Atypical mycobacteria
What are the aims in treating chronic infection?
- Suppress bacterial load
- Treat infective exacerbations
- Reduce inflammation
How can CF manifest itself in the GI tract?
Dysmotility -Meconium ileus -Gastro-oesophageal reflux -Distal intestinal obstruction -Constipation/ rectal prolapse Co-existent disease -Crohn's and coeliac
In what other ways can CF manifest itself?
- Upper airway polyps and sinusitis
- Diabetes
- Osteopenia
- Arthropathy
- Hepatopathy
- Heat ezhaustion
- Bilateral absence of vas deferens
- Vaginal candidiasis: stress incontinence
What are examples of airway clearance techniques?
- Percussion and drainage
- Autogenic drainage
- Active cycle breathing
What are examples of airway clearance adjuncts?
- Positive expiratory pressure mask
- Cornet/ flutter
- High frequency chest wall oscillation
What increases sputum viscosity?
DNA released from neutrophils
What does alfadornase do?
- Breaks down DNA strands
- Eases expectoration of purulent secretions
- Short to medium term benefit and expensive
What does hypertonic saline do?
- Similar efficacy to alfadornase
- Short to medium benefit and cheap
