Cystic Fibrosis

Question 1

Cystic fibrosis definition

Answer 1

Cystic fibrosis (CF) is a multi-system genetic disease leading to recurrent respiratory infections, pancreatic insufficiency and abnormal concentrations of sodium and chloride in sweat.

Question 2

Cystic fibrosis aetiology and pathogenesis

Answer 2

Chromosome 7 mutation to CF transmembrane conductance regulator (CFTR)

• Abnormal CFTR fails to allow chloride ions out of the cell.
• Sodium is then retained by the cell and not left in the mucus.
• Mucus then becomes short of water and has increased viscosity.
• End result is that secretions from the lung bronchi, pancreas, GIT and reproductive tract are water depleted and very viscous.

Question 3

Cystic fibrosis effects

Answer 3

Lungs
Pancreas
GIT
Genitourinary
Other organ complications
- Dehydration
- Osteoarthropathy
- Renal stones
- Gall stones
- Osteoporosis.

Question 4

Cystic fibrosis respiratory effects

Answer 4

• Reduced mucus clearance -> infection

- > Bronchiectasis

Question 5

Cystic fibrosis pancreatic effects

Answer 5

• Reduced pancreatic enzymes secretion leading to local damage to pancreatic tissue, including islet cells
• > End-result can be diabetes mellitus

Question 6

Cystic fibrosis GIT effects

Answer 6

• Excessive absorption of liquid in the large and small intestines.
• > Meconium ileum in neonates.
• > Distal intestinal obstruction syndrome (DIOS) in children and young adults.

Question 7

Cystic fibrosis genitourinary effects

Answer 7

• Obliterated vas deferens due to defective liquid secretion.
• > > 95% of males are azoospermic
• Chronic lung disease on the menstrual cycle, thick cervical mucus that blocks sperm migration and possibly uterine wall abnormalities.
• > 20% females infertile

Question 8

Cystic fibrosis dehydration, renal, hepatic and orthopaedic effects

Answer 8

Dehydration due to heat-induced salt loss from sweat ducts occurs more readily in CF patients.

Increased incidence of osteoarthropathy, renal stones, gall stones and osteoporosis.

Question 9

Cystic fibrosis Investigations

Answer 9

Sweat Test
- Pathognomonic for CF. Elevated sweat sodium and chloride levels

Genetic testing
- DNA mutations in 90% of CF sufferers

Investigation of complications

• Lung function tests
• Sputum microscopy
• Malabsorption tests and more

Question 10

Cystic fibrosis management

Answer 10

Respiratory
GIT
Other

Question 11

Cystic fibrosis respiratory management

Answer 11

Physiotherapy to aid clearance of secretions
Bronchodilators
Antibiotics (aggressively) for infections
Exercise
NSAIDs and corticosteroids
Mucolytics - Aerosolised DNase (domase alpha)
Lung transplantation

Question 12

Cystic fibrosis GIT management

Answer 12

High calorie diet
Pancreatic enzyme replacements (90%)
Fat soluble vitamin supplements

Question 13

Cystic fibrosis other management

Answer 13

CF Related diabetes
Osteoporosis screening and treatment
Arthritis, sinusitis and vasculitis treatment
Fertility and genetic counselling

Question 14

Cystic fibrosis prognosis

Answer 14

Due to improvements in therapy >41% of patients are adults and 13% are past the age of 30.
The median survival is >30 years, making cystic fibrosis no longer a paediatric disease.
Most (95%) die from lung infection complications.
There is no cure.