Cystic fibrosis Flashcards
What is it?
CF is an autosomal recessive disease leading to mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR
This can lead to a multisystem disease (most commonly affecting the respiratory and gastrointestinal systems but can affect any part of the body with CFTR) characterised by thickened secretions.
What mutation causes it? chromosome ?
Mutation of CFTR gene on Chromosome 7
Pathophysiology?
- CFTR pumps out CL- ions into mucus secretions and takes CL- out of sweat secretions
- Therefore in areas where mucus is produced it allows lubrication of the secretions as water follows CL-
- If it is mutated the CL- ions are not pumped out and water will not follow making the secretion more thick and sticky impacting clearance and movement of it
- Most commonly impacts the Respiratory tract- impaired mucociliary function and the GI tract
Symptoms in newborns ?
Meconium ileus
- In 15-20% of newborn CF infants the bowel is
blocked by the sticky secretions. There are signs of intestinal obstruction soon after birth with bilious vomiting, abdominal distension and delay in passing meconium.
- Can cause sepsis if bowel perforates→ organ failure and death
Meconium ileus on AXR shows ?
- Air fluid levels
- Dilated bowel loops
- “soap bubble”
Symptoms in early childhood?
- Pancreatic insufficiency - thick secretions block pancreatic duct- Intestinal malabsorption
- Steatorrhea- increased fat in the stool
- Poor weight gain- failure to thrive - nutrients and fat-solube vitamins lost in stool
- Could get pancreatitis as pancreatic enzymes blocked in duct get activated and start digesting the pancreas
- Decreased endocrine function of pancreas
- Insulin-dependant Diabetes mellitus
- Avitaminosis A
- Squamous metaplasia of epithelial lining of pancreatic exocrine ducts
Teenager/early adulthood symptoms?
- Recurrent Chest infections
- Chronic bacterial infections and inflammation
- Lead to a mucus plug
- This can cause bronchiectasis
- Infants & children colonised with Gram +ive = Staph aureus or MRSA
- Teens & Adults colonised with Gram -ive = Pseudomonas aeruginosa→ builds biofilms
- Infertility in males and subfertility in females
Causes of death?
> 80% due to infections like pneumonia and bronchiectasis
how to diagnose?
One or more of the characteristic phenotypic features -
- Or a history of CF in a sibling
- Or a positive newborn screening test result
And
- An increased sweat chloride concentration
(> 60 mmol/l) – SWEAT TEST
- Or identification of two CF mutations – genotyping
- Or demonstration of abnormal nasal epithelial ion transport (nasal potential difference)
Management: lifestyle advice given ?
- No smoking
- Avoid other CF patients
- Avoid friends / relatives with colds / infections
- Avoid jacuzzis (pseudomonas)
- Clean and dry nebulisers thoroughly
- Avoid stables, compost or rotting vegetation – risk of aspergillus fumigatus inhalation
- Annual influenza immunisation
- Sodium chloride tablets in hot weather / vigorous exercise
Main Treatment for chest?
- Chest Physiotherapy- airway clearance
- Exercise
- Mucolytics treatment- can be nebulised DNase (pulmozyme)
-Long-term antibiotics (sometimes inhaled or nebulised) - Novel CFTR modulators / potentiators (e.g. Kaftrio)
Treatment for pancreas symptoms
- Pancreatic enzyme replacement (eg.Creon) if pancreatic insuffieciency
- Fat-soluble vitamin (A,D,E,K) replacement
- Optimisation of CF related diabetes – this occurs in approximately 1 in 3 adults with CF and if present requires insulin therapy
What do novel CFTR modulators/potentiators do?
excellent efficacy with improvements in FEV1, weight, quality of life and a reduction in frequency of infective exacerbations
What monitoring must be done ?
CF related diabetes
CF related liver disease
osteoporosis
What are the complications that can occur
Respiratory Infections
Low Body Weight
Distal Intestinal Obstruction Syndrome (DIOS)
CF Related Diabetes
Gallstones
Rectal prolapse
Infertility
