CF

Question 1

Higher levels of what molecule might indicate a CF diagnosis?

Answer 1

Trypsinogen

Question 2

Clubbing of fingers, poor weight gain, and what else are Sx of cystic fibrosis?

Answer 2

Salty sweat, foul smelling stool, frequent respiratory infections

Question 3

How is male fertility affected by CF?

Answer 3

Makes males infertile due to the impact on the vas deferens. Women are still fertile

Question 4

Which mutations of the CFTR protein result in no function? And which result in varying function

Answer 4

Mutations 1, 2 and 3 = no function
4-6 = varying function

Question 5

Mutation 2, involving Phe508del, makes up 72% of cases. Describe this mutation

Answer 5

The protein is made, but does not get exocytosed onto the cell surface. No channel in the membrane

Question 6

Mutation 3, involving Gly551Asp, makes up 4-5% of cases. Describe this mutation

Answer 6

The channel gets made and inserted into the membrane, however it is unstable and does not open very well.

Question 7

Why do CF pts get thick mucus in the airways?

Answer 7

Because chloride is trapped inside the cell. Therefore, water enters the cell, rather than being in the extracellular space. Causes thick mucus that the cilia cannot clear - leads to airway infections and tissue damage due to subsequent immune response

Question 8

Main pathogen for CF infections of the airway?

Answer 8

Pseudomonas aeruginosa

Question 9

Antibiotic of choice for common CF pathogen?

Answer 9

Tobramycin

Question 10

Symptomatic Tx options for CF patients?

Answer 10

Physiotherapy to mechanically clear mucus
Glucocorticoids to relieve obstruction
Mucolytics or DNA-ase’s (like dornase alpha) to reduce mucus viscosity

Question 11

Ivacaftor is effective against which mutation?

Answer 11

Mutation 3 (551). Only effective for 4-5% of patients.
Only works to stabilise the open phase of the channel

Does not work against F508del mutation.