cystic fibrosis

Question 1

what is the common infectious organism associated with bronchiectasis + cystic fibrosis called?

Answer 1

pseudomonas aeruginosa

Question 2

what is cystic fibrosis?

Answer 2

common autosomal recessive disorder

Question 3

what is mutated in cystic fibrosis?

Answer 3

transmembrane conductance regulator protein (CFTR)

Question 4

where is the mutation coded on?

Answer 4

chromosome 7

Question 5

what is the most common mutation called?

Answer 5

delta-F508

Question 6

what does abnormal protein channel function (CFTR ) lead to ?

Answer 6

chloride being trapped in the cell

Question 7

what 4 things does the movement of sodium and water into the cell lead to?

Answer 7

• airway surface dehydration
• bacteria collection
• difficulty in coughing
• shearing (accumulation of mucus)

Question 8

what does decreased mucociliary clearance lead to?

Answer 8

• frequent pulmonary infections with bacterial colonisation
  -> chronic damage to pulmonary tree
  –> abnormal dilation (bronchiectasis)

Question 9

what are 3 extrapulmonary effects/

Answer 9

fat malabsorption due to pancreatic insufficiency

risk of osteoporosis

risk of type 2 diabetes

Question 10

what are 5 presentations of cystic fibrosis?

Answer 10

abnormal stools (pale, offensive, float)

chronic productive cough

failure to thrive, weight gain + difficulty growing

haemoptysis

recurrent chest infections

Question 11

what are 7 presentations of cystic fibrosis?

Answer 11

bronchiectasis

chest infections

haemoptysis

infertility

meconium ileus (bowel obstruction)

pancreatic insufficiency

type 2 diabetes

Question 12

what is used to diagnose this?

Answer 12

Newborn blood spot testing is performed on all children shortly after birth and picks up most cases

The sweat test is the gold standard for diagnosis

Genetic testing for the CFTR gene can be performed during pregnancy by amniocentesis or chorionic villous sampling, or as a blood test after birth

Question 13

what is the treatment for CF?

Answer 13

MDT approach

Maintaining lung function (physiotherapy, postural drainage, mucolytics)

Monitoring lung bacteriology (antibiotics)

Consider referral for a lung transplant

Nutritional support

Enzyme replacement

Vitamin replacement (A, D, E & K)

Frequent weight review

Endocrine

Annual screening for CF-related diabetes

Fertility advice

Pseudomonas pneumonia - nebulised antibiotics e.g. tobramycin and oral ciprofloxacin