cystic fibrosis Flashcards
cystic fibrosis inheritance pattern
autosomal recessive
-> defect in cystic fibrosis transmembrane conductance regulator gene (CFTR), which codes a cAMP-regulated chloride channel
delta f508 - long arm chrom 7
**increased viscosity of secretions **(lung + pancreas)
organisms that may colonise CF patients
staph aureus
pseudomonas aeruginosa
aspergillus
bukholderia (pseudomonas) cepacia
how does cystic fibrosis typically present
neonatal - meconium ileus, prolonged jaundice
malabsorption - steatorrhoea, failure to thrive
recurrent chest infections - 40%
others - liver disease
other features/associations with CF
- short stature
- diabetes
- delayed puberty
- rectal prolapse (due to bulky stools)
- nasal polyps
- male infertility/ fem subfertility
diagnosing cystic fibrosis
sweat test
- CF has abnormally high sweat chloride
- CF if >60
causes of a false positive sweat test
- malnutrition
- adrenal insufficiency
- glycogen storage disease
- nephrogenic diabetes insipidus
- hypothyroidism
- G6PD
- ectodermal dysplasia
commonest cause of false negative CF test
skin oedema due to hypoalbuminaemia/proteinaemia secondary to pancreatic exocrine insufficinecy
key management of CF
- 2x daily chest physio + postural drainage
- high calorie diet
- vitamin supplementation
- pancreatic enzyme supplements, taken with meals
- lung transplant
rules around CF patients interacting
minimise contact with each other to prevent cross infection with Burkholderia cepacia + pseudomonas aeruginosa
contraindication of CF patient receiving lung transplant
chronic infection with Burkholderia cepacia
lumacaftor/Ivacaftor (Orkambi)
used to treast CF who are homozygous for the delta F508 mutation
- lumacaftor increases no. of CFTR proteins that are transported
- ivacaftor - increases opening of defective channel
how is CF detected in neonatal period
heel prick
