Cystic fibrosis

Question 1

What are the genetic problems associated with CF

Answer 1

• 1/25 carriers
• 1 in 2000-2500 live births
• Commonest mutation 𝚫F508

Question 2

What type of genetic disorder is CF

Answer 2

Autosomal recessive disorder
Most common in Caucasian

Question 3

Where is the mutation

Answer 3

transmembrane conductance regulator protein (CFTR) on Chr 7

Question 4

What does this protein normally do

Answer 4

normal protein allows chloride to move out of cell
no mucus build up

Question 5

What does a mutated protein cause

Answer 5

abnormal protein= chloride stuck in cell
Na+ and H2O stay with chloride
mucus build up outside of cell

Question 6

What is the effect of mucus build up

Answer 6

Mucus collects bacteria
↓ mucociliary clearance
Mucus sticks to mucosa, causing inflammation + ↑ bacterial access which decreases bacterial killing

Question 7

What are the 6 classification of mutaion in CTFR

Answer 7

1-3 severe disease
- Pancreatic insufficient
- 𝚫F508 class 2= severe disease

4-5 milder disease
- Some pancreatic function

Question 8

What are the complications of CFTR

Answer 8

Pancreatic insufficency
Repeated Lung infection
Progressive bronchiectasis
Scarring
Abscesses
Type 2 DM
Osteoporosis

Question 9

What is the effect of pancreatic insuffeciency

Answer 9

• Lack of pancreatic enzymes (trypsin, colistin)
• Fat Malabsorption
• Abnormal stool-steatorrhea
• Failure to thrive

Question 10

What is the effect of repeated lung infection

Answer 10

• Pseudomonas aeruginosa
• Burkholderia cepacia (genomovar III)
• Non tuberculous mycobacteria

Question 11

What is the effect of Osteoporosis

Answer 11

Decrease bone mineral densisty
Increased fracture risk

Question 12

What are the other effects of these complications

Answer 12

Progressive resp decline
Chronic sputum production
Survival related to FEV1
Increasing SOB

Question 13

What are some less common complications of CFTR

Answer 13

• Risk of pneumothorax
• Nail clubbing
• Male infertility (NO vas deferens)
• Meconium ileus
• Haemoptysis due to bronchial wall destruction

Question 14

What does antenatal testing involve

Answer 14

• Pre-implantation genetic diagnosis
• Chorionic villus sampling
• Amniocentesis

Question 15

What does neonatal testing involve

Answer 15

New-born bloodspot day 5 (Guthrie test)
- if +ve-> clinical assessment & sweat test
Sweat test- measure chloride concentration in sweat, >60 mmol/l= abnormal

Question 16

What are the outcomes of the testing

Answer 16

1. CF
2. Not CF
3. CF- screen positive inconclusive diagnosis (SPID)

Question 17

What is the management for CF

Answer 17

Uses MDT

Question 18

What is the management for progressive respiratory decline

Answer 18

• Oxygen
• Nocturnal NIV
• Lung transplant

Question 19

What is the management for mucus obstruction

Answer 19

• Airway clearance via physio
• Mucolytics
• Bronchodilators

Question 20

What is the managment for lung infection

Answer 20

• Antibiotics (oral, IV, nebulised)

Question 21

What is the management for increased inflammation

Answer 21

• Azithromycin

Question 22

What is the management for scarring

Answer 22

Symptom management

Question 23

What is the management for pancreatic insufficency

Answer 23

• Replace enzymes
• High energy diet
• Fat soluble vitamin + mineral supplement

Question 24

What is the management for type 2 DM

Answer 24

• Insulin (oral drugs not useful)
• Problem with diet compliance

Question 25

What is the management for osteoperosis

Answer 25

• Bone protection drugs
• Weight bearing exercise

Question 26

What is the management for haemoptysis

Answer 26

Minor - no treatment
Massive, preceded by gurgling in chest
- Admit, resuscitate
- Bronchial angiogram + embolisation

Question 27

What else can be used

Answer 27

Segregation and infection control policies

Question 28

What is the effect of modulator drugs

Answer 28

KAFTRIO
-> small benefit in lung function
-> ↓ chest exacerbations
-> ↑ weight & QoL