Cystic Fibrosis Vignette

Question 1

What is the function of the CFTR protein?

Answer 1

-functions as an epithelial ion channel and controls the movement of salt and water into and out of the cells.

Question 2

What kind of protein is CFTR?

Answer 2

ATP-binding cassette (ABC).

Question 3

The most common mutation for CF is _____.

Answer 3

F508del / F508del

Question 4

Describe the Pathogenesis of CF Lung Disease.

Answer 4

Abnormal gene–> abnormal protein-> defective ion transport–> airway surface liquid depletion –> impaired mucociliary clearance—–> leading to the cycle of destruction.

Question 5

How many types of CF are there? Describe them.

Answer 5

Type I: no synthesis.

Type II: Abnormal conformation of CFTR protein and the body will break it down.

Type III: Block in gating.

Type IV: Altered conductance. The channel exists but it doesn’t function normal.

Type V: Reduced synthesis of CFTR.

Question 6

Describe the cycle of destruction

Answer 6

Mucus obstruction –> infection –> inflammation –>scarring —> leads to more mucus obstruction and just repeats…

Question 7

The more serious classes of CF are ____.

Answer 7

Type I, II, and III.

Question 8

What are the Clinical features of CF

Answer 8

Sinuses: sinus issues, nasal polyps

Lungs: Endobronchitis, bronchiectasis

Pancreas: exocrine insufficiency (90%), CF related diabetes.

Intestine: Newborns with meconium ileus (10-15%), constipation, Distal intestinal obstructive syndrome (DIOS),

Liver: Cholestasis, focal sclerosis, cirrhosis. Vas deferent: failure to develop (male infertility)

Sweat gland: salt-losing dehydration.

Question 9

How is the diagnoses for CF made?

Answer 9

°New born screening –> test for pancreatic enzyme IRT from the heel prick test.

°Sweat Test–> sweat chloride level equal or greater than 60 mM.

Question 10

Children are more subject to ____ infections while adults more often get ____ infections.

Answer 10

staph aureus; pseudomona aeruginosa

Question 11

Treatment options for CF

Answer 11

• Higher than normal metabolism so patien’ts adapt a high fat and protein diet.
• Enzymes to help bypass the role of the pancreas due to the pancreatic insufficiency.
• Jacket that shakes the lungs to loosen the mucous.
• Inhalents

Question 12

What is the prognosis?

Answer 12

• Improved prognosis due to developmetn of supplemental enzymes and more improvemnt after the inhalent treatments were developed.
• Predicted livelihood is into the ~40’s now. This was below a 10 year life expectancy some 50 years ago.