Cystic Fibrosis in children and adults Flashcards
Is cystic fibrosis common?
Cystic fibrosis is the commonest inherited, life-shortening, disorder amongst N. European populations.
- Inherited as an autosomal recessive trait.
- Gene prevalence = 1:25
Features of the Cystic Fibrosis Gene
- Lies on the long arm of chromosome 7
- Cystic fibrosis transmembrane conductance regulator (CFTR)
- Different mutations can result different phenotype of disease: 6 classes, commonest phe508del.
Functions of the CFTR gene
- Cilial collapse: Active transport channel for chloride (HCO3), regulates liquid volume on epithelial surface = reduced chloride (HCO3) efflux, increased sodium influx via ENaC.
- Excessive, innate inflammation
- Thick sticky mucus
Pathophysiology of airway epithelia
Traps organisms, chronic infection, excessive DNA from neutrophil apoptosis.
Presenting features of cystic fibrosis in antenatal
common: CVS, Echogenic bowel
Less common: Perforated meconium ileus
Presenting features of cystic fibrosis in neonatal
Common: Screening, Mec ileus (10%)
Less common: Gut atresia, obstructive jaundice, Vitamin deficiencies
Presenting features of cystic fibrosis in infants and young children
Common: Recurrent chest infections, Failure to thrive
Less common: Rectal prolapse, Pseudo-Bartter’s syndrome, Anaemia, oedema, hypoproteinaemia
Presenting features of cystic fibrosis in older children and adults
Common: recurrent chest infections, Nasal polyps and sinusitis, Male infertility
Uncommon: Acute pancreatitis, Liver disease, Pseudo-Bartter’s, Atypical mycobacteria
How to make a diagnosis for CF in children
- Clinical assessment
- Sweat test (chloride)
- Repeat CF mutation analysis
Antenatal screening (following identification of CF patient)
- Pre-implantation genetic diagnosis
- Chorionic villus sampling
- Amniocentesis
Management methods of cystic fibrosis
- Multi-organ disease: specialist multi-disciplinary team (improved long-term outcome)
- Shared care with local clinics
- Primary care: surveillance, early treatment of infection
What are the two cardinal features of CF?
- Pancreatic insufficiency (85-90%): abnormal stools, failure to thrive.
- Recurrent bronchopulmonary infection: pneumonitis, bronchiectasis, scarring, abscesses.
Treatment of pancreatic insufficiency
- Enteric coated enzyme pellets
- High energy diet: low fat
- Fat-soluble vitamin and mineral supplements
What is the vicious cycle of CF lung disease?
Mucus obstruction, infection»_space; Infection (chronic)»_space; Increased inflammation»_space; Fibrosis/scarring/bronchiectasis
Therapeutic targets for mucus obstruction, inflammation
Airway clearance physiotherapy, Dornase alfa, Hypertonic saline
Therapeutic targets for infection (chronic)
Antibiotics
Therapeutic targets for increased inflammation
Azithromycin
Common respiratory pathogens in CF
- Staphlococcus aureus and Haemophilus influenzae in early years
- Pseudomonas aeruginosa in later years
Less common respiratory pathogens in CF
- Burkholderia cepacia
- Stenotrophomonas maltophilia
- MRSA
- Atypical mycobacteria e.g. M abscessus
- Lung microbiome
CF - respiratory tract infections
- Early years: Pre-infection, eradication of early infection (80-90%)
- Chronic infection (usually Pa, Sa and Hi)
- Reduce inflammation: Ibruprofen, azithromycin, prednisolone
Other manifestations/complications of CF
- GI: dysmotility, co-existent disease
- Hepatopathy
- Upper airway polyps and sinusitis
- Dysglycaemia (diabetes): more common in adults
- Bones: Osteopenia, Arthropathy
- Heat exhaustion
- Bilateral absence of vas deferens
- Vaginal candidiasis, stress incontinence
What are social, educational and economic impacts on child and family due to CF?
- Barriers to making friends
- Increased depression/anxiety
- Low adherence to time-consuming treatments
- Increased costs to the family
