Cystic Fibrosis

Question 1

cystic fibrosis cause?

which gene mutated

Answer 1

delta f508 mutated (80% of cases) on CFTR gene of chromosome 7

Question 2

what is CFTR?

Answer 2

Cl- channel

Question 3

CFTR stands for what?

Answer 3

cystic fibrosis transmembrane regulator gene

Question 4

cystic fibrosis mode of inheritance?

Answer 4

Autosomal recessive

Question 5

Pathophys of cystic fibrosis?

step by step

Answer 5

CFTR shape is malformed > Cl- can not pass through CFTR channel > Cl- cannot get int lung mucus (or any secretion really) > water does not follow > mucus becomes very thick

Question 6

If Cl- can not move what other electrolytes can not move into skin?

Answer 6

Na+

Question 7

Lung mucus very thick, what will this cause?

-2

Answer 7

breathing is difficult + infections

Question 8

recurrent lung infections will eventually cause what complication?

Answer 8

bronchiectasis

Question 9

Lung mucus very thick, what can happen to pulmonary vasculature blood pressure?

Answer 9

pulmonary HTN

Question 10

pulmonary HTN will lead to what eventually?

Answer 10

cor pulmonale

Question 11

in cystic fibrosis what happens to pancreas?

Answer 11

Pancreas secretion are very thick

Question 12

Pancreas secretion are very thick, effect of this?

Answer 12

thick secretions block exocrine enzyme leaving pancreas > malabsorption

Question 13

what happens at the liver in CF?

Answer 13

Bile very thick > bile ducts blocked

Question 14

blocked bile ducts will cause what complications?

-2

Answer 14

liver fibrosis

cirrhosis

Question 15

liver fibrosis eventually leads to what?

Answer 15

Portal HTN

Question 16

what happens to sweat in CF?

Answer 16

sweat is high in chloride

Question 17

why is there high Cl- sweat in CF?

Answer 17

CFTR not functioning > ions from sweats ducts can not be resorbed > instead Cl- in sweat ducts gets trapped and then pumped into skin

Question 18

what CF problem happens to men specifically?

why?

Answer 18

Male infertility

do not have vas deferens

Question 19

why do men not have vas deferens?

Answer 19

when in womb the thick mucus blocks vas deferens being made

Question 20

vas deferens not being made is called what medically?

Answer 20

vas deferens agenesis

Question 21

what CF problem happens to women specifically?

why?

Answer 21

female subfertility

mucus in cervix way too thick

Question 22

Thick mucus in sinus will cause a lot of what?

-1

Answer 22

infections (easily infected)

Question 23

recurrent sinus infections will cause what in the sinuses to be formed?

Answer 23

nasal polyps

Question 24

how many CF pts are diagnosed over 18?

Answer 24

5%

Question 25

when are most CF pts diagnosed?

Answer 25

as babies

Question 26

which organisms which may colonise CF patients lungs? -4

Answer 26

Staphylococcus aureus Pseudomonas aeruginosa Burkholderia cepacia Aspergillus

Question 27

features (signs and symptoms) of CF?

Answer 27

Lots of chest infections Malabsorption (30%): steatorrhoea, failure to thrive ``` Foul smelling stool Short stature Diabetes mellitus Delayed puberty – can’t get fat Rectales prolapse (due to bulky stools) Nasal polyps Male infertility Female subfertility Liver disease ```

Question 28

``` why is there: Foul smelling stool Short stature Diabetes mellitus Delayed puberty – can’t get fat ?? ```

Answer 28

No pancreas enzymes

Question 29

which test can you use to diagnose CF antenatally?

Answer 29

chorionic villus sampling or amniocentesis

Question 30

which test is used to diagnose CF neonatally?

Answer 30

Guthrie heel-prick test

Question 31

which test is used to diagnose CF in children?

Answer 31

sweat test

Question 32

suspected CF neonate will have what test? this test is looking for what?

Answer 32

Guthrie heel-prick test serum immunoreactive trypsinogen (IRT)

Question 33

suspected CF child will have what test? this test is looking for what?

Answer 33

Sweat Test high Cl- in sweat

Question 34

normal Cl- levels in sweat?

Answer 34

< 40 mEq/l

Question 35

abnormal Cl- levels in sweat?

Answer 35

> 60 mEq/l

Question 36

if CF confirmed in child what test do you do with family? what mutation are you looking for?

Answer 36

Gene test pt/relatives/partners Δ-F508 - (this is most common mutation)

Question 37

why do CF pts have skin oedema?

Answer 37

Hypoalbuminaemia

Question 38

skin oedema can cause what problems when Ix CF?

Answer 38

False negative sweat test

Question 39

what IX can you consider? and why/ what are you looking for? -6

Answer 39

Spirometry – <0.7 obstructive Sputum sample – do if infected or want to check if pt been colonised Faecal elastase – pancreatic insufficiency CXR – check bronchiectasis CT scans – signet rings + tram tracks (diagnostic for bronchiectasis and Gold.S) LFTs – check liver health

Question 40

how do you manage the mucusy lungs? | -3

Answer 40

chest physiotherapy + postural drainage 2x a day deep breathing is good acute breathing exacerbation – salbutamol

Question 41

how do you manage the lack of pancreas enzymes/ malabsorption? -4

Answer 41

Eat lots of calories Eat lots of fat Take vitamins supplement (ADEK) Take pancreatic enzyme supplements (pancreatin)

Question 42

how do you manage increased risk of infections in CF patients? -3

Answer 42

CF people ought not meet other CF people – risk of cross infection Extra vaccine doses Prophylactic antibiotics given sometimes

Question 43

Last line Mx for CF?

Answer 43

lung transplant

Question 44

what drugs can be used to specifically target the CFTR protein? -2

Answer 44

Lumacaftor Ivacaftor

Question 45

what drugs can be used to specifically target the CFTR protein? -2 named e.g. how does each work?

Answer 45

Lumacaftor - ↑number of CFTR protein transported into cell surface Ivacaftor - lets CFTR open and allow Cl- in

Question 46

most CF pts die at what age?

Answer 46

40

Question 47

CFTR gene located on which chromosome?

Answer 47

chromosome 7