Cystic Fibrosis

Question 1

What is the most common autosomal recessive disorder in Caucasians?

Answer 1

Cystic fibrosis

Question 2

What is the main cause of morbidity and mortality in CF?

Answer 2

Pulmonary (lung) disease

Question 3

What causes 90% of deaths in CF?

Answer 3

Respiratory failure

Question 4

If both parents are carriers, what’s the probability of a child being affected?

Answer 4

1 in 4

Question 5

If both parents are carriers, what’s the probability of a child being a carrier?

Answer 5

2 in 4

Question 6

If both parents are carriers, what’s the probability of a child being unaffected?

Answer 6

1 in 4

Question 7

How does CF occur?

Answer 7

Due to mutation in the transmembrane regulator protein which is coded on chromosome 7

Question 8

What happens as a result of abnormal transport chloride and sodium?

Answer 8

Reduced airway surface liquid
Thick sticky mucous
Shearing
Impaired bacterial killing via neutrophils

Question 9

How many mutation classes are there in cystic fibrosis?

Answer 9

6

Question 10

What are the mutation classes for CF based on?

Answer 10

Synthesis
Processing/trafficking
Function of CFTR

Question 11

What is the most common mutation type?

Answer 11

Delta F508

Question 12

How is CF diagnosed?

Answer 12

Pre-implantation genetic diagnosis
Chorionic villus sampling
Amniocentesis
Guthrie test - newborn bloodspot day 5

Question 13

What does a sweat test measure?

Answer 13

Measures the concentration of chlorides exerted in sweat.

It’s often elevated in CF

Question 14

How many diagnostic outcomes do prenatal, antenatal and postnatal testing give you?

Answer 14

3
CF
NOT CF
CF - screen positive inconclusive diagnosis

Question 15

Where can CF affect?

Answer 15

Anywhere in the body (multisystem disease)

Question 16

What is pancreatic insufficiency?

Answer 16

1. The CTFR mutation also affects the pancreas
2. The pancreas produces enzymes that digest food. Lack of enzymes causes: malabsorption, abnormal stools (pale, float), failure to thrive
3. Importance of record, growth charts

Question 17

what are the classes of pancreatic function?

Answer 17

6 classes of CF disease 
Thus 6 levels of function in the pancreas
- class 1-3 are pancreas insuffiencent
- class 4-6 have some pancreatic function

Question 18

What percentage of CTFR is needed to have sufficient pancreatic function and be asymptomatic?

Answer 18

5%

Question 19

What is recurrent bronchopulmonary infection?

Answer 19

Pneumonia
Bronchiectasis
Scarring
Abscesses

Question 20

What does a CTFR abnormality cause?

Answer 20

Abnormal electrolyte transport across cell membrane
Dehydration of airway surface layer (allows mucous to slide across airways and be coughed up)
Decreased mucociliary clearance
Mucous sticks to the mucosal surface and causes shearing damage
Increased bacterial adherence
Decreased bacterial killing

Question 21

How do CF patients get repeated respiratory infections?

Answer 21

Vicious circle of events

Question 22

What happens as a result of recurrent chest infections?

Answer 22

They get progressive respiratory decline.

Question 23

What signs of CF does CT show?

Answer 23

Tramlines
Signet rings
Mucous plugging
Consolidation

Question 24

How is CF managed?

Answer 24

It is multi organ disease and needs and MDT to improve long term outcome.

Question 25

How do you treat of pancreatic insufficiency in CF?

Answer 25

Boosting nutrition - giving lots of energy, sweets etc.

Question 26

How is diabetes in CF different?

Answer 26

It is different to non CF patients and its management is difference.

Question 27

What happens to bone mineral density in CF patients?

Answer 27

It decreases in about one third of people.

Question 28

How is pneuthorax affect CF patients?

Answer 28

Affects 3-4% CF patients in their lifetime

Question 29

How is haemoptysis different in CF?

Answer 29

This is due to bronchial wall destruction.

Question 30

How common is minor haemoptysis?

Answer 30

60% blood streaking and no specific treatment.

Question 31

How common is massive haemoptysis?

Answer 31

1%

Question 32

What are the risk factors for massive haemoptysis?

Answer 32

Gurgling in the chest
Admit, resuscitate
May need bronchial angiogram or embolism.

Question 33

How much drugs do CF patients take?

Answer 33

A lot

Question 34

What do the new modulator drugs address?

Answer 34

They address different parts of CFTR production, processing, folding, transport and insertion into the membrane.

Question 35

How much benefits do the new modulator have on lung function?

Answer 35

Small

Question 36

Where is the more significant benefit for new modulator drugs?

Answer 36

Chest exacerbation, weight gain and quality of life.

Question 37

What are the indications of lung transplant in CF?

Answer 37

Rapidly deteriorating lung function
FEV1 < 30% predicted 
Life threatening exacerbation 
Estimated survival < 2 years 
Recurrent pneumothorax, recurrent severe haemoptysis.

Question 38

Are there any contra-indications to lung transplant?

Answer 38

Yes

Question 39

Are there some relative contra-indications to lung transplant and what do you have to use to make the decision?

Answer 39

Yes and you have to use clinical judgement.

Question 40

What has allowed CF patients to survive?

Answer 40

CF centres 
MDT teams 
Physiotherapy
Nutrition
Enzymes
Antibiotics 
Aggressive approaches 
Annual flu/pneumococcus