Cystic Fibrosis

Question 1

Gene Prevalence?

Answer 1

1:25 population risk

Question 2

What kind of gene is cystic fibrosis?

Answer 2

Autosomal recessive

Question 3

What is the gene involved?

Answer 3

CFTR gene
Codes for CFTR protein
Channel moves Chlorine out of cells

Question 4

What is the most common gene mutation?

Answer 4

DELTA F508

Question 5

How many classes of mutation?

Answer 5

1-5

Question 6

Which is the most severe?

Answer 6

Class 1= short mRNA = no CFTR channels

Question 7

Least severe?

Answer 7

Class 4 & 5 = defective or decrease number of channels.

Question 8

How does this impact on function?

Answer 8

In Cystic Fibrosis- not enough Chlorine channels
Cl not moved out of cells
Low Cl outside cells
Fluid accumulation, cilia collapse
Excess mucus and low bacterial clearance
Inflammation & Infection

Question 9

Signs in children?

Answer 9

Recurrent chest infection
Failure to thrive
Nasal Polyps and sinusitis

Question 10

How can CF be detected in newborns?

Answer 10

Neonatal screening (Guthrie bloodspot test)

Question 11

When is the Guthrie test done?

Answer 11

Day 5

Question 12

What does the test look for?

Answer 12

Immunoreactive Trypsinogen

Then screen for 5 specific mutations

Question 13

What follow up tests can be done?

Answer 13

Sweat test >60 = CF

Question 14

Common problems in adulthood

Answer 14

• Pancreatic Insufficiency

- Recurrent Bronchopulmonary Infection

Question 15

Give examples of Bronchopulmonary Infections

Answer 15

Pneumonia

Question 16

What does recurrent infection lead to?

Answer 16

Bronchiectasis= reduced clearance
Scarring
Abscesses

Question 17

Why Pancreas (PI)?

Answer 17

Pancreatic duct is obstructed by the thickened mucus
No lipase released
Absence of Lipase = cant utilise fat soluble vitamins (ADEK)

Question 18

Treatment of PI?

Answer 18

PERT- enzyme replacement therapy
High energy diet
Proton pump inhibitors (help delivery to small bowel)

Question 19

Management of Infections?

Answer 19

• Prevention

- Early eradication

Question 20

Prevention of infection?

Answer 20

• Mucolytics
• Physio to clear mucus
• Avoidance of germy people
• Vaccinations
• Prophylaxis (flucloxacillin)

Question 21

Early Eradication?

Answer 21

• Staph Aureus/ Haemophilus Influenza
• Nebuliser and dry powder
• Prednisolone, Ibuprofen, Azithromycin

Question 22

Other problems?

Answer 22

• GI (meconium ileus, GOR, constipation)
• Crohn’s Disease, Coeliac
• Liver disease
• polyps and sinusitis
• Diabetes

Question 23

Causative organisms

Answer 23

Pseudomonas Aeruginosa- slime, forms a biofilm- protected against immune response.
Burkholderia Cepacia- resistant to AB- contraindication for Transplant.
Stenotrophomonas Maltophila- ??
Mycobacterium Abscessus- no transplant resistant to all drugs.

Question 24

Treatment for Pseudomonas Aeruginosa

Answer 24

Ciprofloxacin & nebulised Colomycin 3/12

Question 25

Methods of Admin

Answer 25

• Early and aggressively
• Oral= staph, haemophilus, pneumococcus
• IV = pseudomonas, stenotrophamonas, burkholderia

Question 26

Treatment for Staph/Step/Pneumococcus?

Answer 26

B-lactam & Aminoglycosides (double dose) 2/52

Question 27

New treatment?

Answer 27

Ivacaftor

• Binds to CFTR to improve Cl transfer
• only in celtic mutation (G551D)

Question 28

Last resort?

Answer 28

Lung transplant

-Double lung transfer

Question 29

When to transplant?

Answer 29

• Rapid deterioration
• FEV1 <30%
• Survival <2 years
• But have to be well enough to survive op

Question 30

Contraindications to transplant?

Answer 30

-Malignancy
-Obese
-Mentally unstable
-No support network
-Other comorbidities- organ failure
-Smoker
-Infection
M.A or B.C.