Cystic Fibrosis

Question 1

Cystic fibrosis (CF) is an inherited condition in which the lungs and digestive system can become clogged with thick, sticky mucus. What is the incidence of CF?

1 - 1 / 200
2 - 1 / 2000
3 - 1/ 20,000
4 - 1 / 200,000

Answer 1

2 - 1 / 2000
- most common inherited disease in white populations

Question 2

Does cystic fibrosis present at a specific age?

Answer 2

• no
• can present at any age

Question 3

How is cystic fibrosis inherited?

1 - X-linked recessive
2 - X-linked dominant
3 - autosomal recessive
4 - autosomal dominant

Answer 3

3 - autosomal recessive
- need 2 mutated copies of the CFTR gene
- 25% chance offspring will develop CF if both parents are carriers

Question 4

Cystic fibrosis (CF) is an autosomal recessive disease. Specifically, which gene is mutated that causes CF?

1 - HER2
2 - c-MYC
3 - CFTR
4 - BRCA1

Answer 4

3 - CFTR
- Cystic Fibrosis Transmembrane Regulator
- this gene encodes the CFTR protein
- located on chromosome 7

Question 5

Although not affected, people can still be a carrier for the mutated CFTR gene. How many people is it estimated carry this?

1 - 1/25
2 - 1/250
3 - 1/2500
4 - 1/25,000

Answer 5

1 - 1/25

Question 6

There are lots of different types of mutation in the Cystic Fibrosis Transmembrane Regulator (CFTR) gene, but which is most common?

1 - deltaF508
2 - V520F
3 - R117H
4 - G551D

Answer 6

1 - deltaF508
- typically causes misfolding of protein in endoplasmic reticulum
- less CFTR will be present in membranes

Question 7

There are different types of mutations. Which is responsible for causing the mutation in the cystic fibrosis transmembrane regulator?

1 - substitution
2 - deletion
3 - insertion
4 - translocation

Answer 7

3 - insertion
- this is a Single nucleotide polymorphisms

Question 8

The cystic fibrosis transmembrane conductance regulator (CFTR) is a transmembrane pump that is involved in pumping which ion from inside the cell to outside the cell?

1 - Na+
2 - Cl-
3 - K+
4 - Ca2+

Answer 8

2 - Cl-

Question 9

The cystic fibrosis transmembrane conductance regulator (CFTR) is a transmembrane Cl- pump that is involved in pumping Cl- from inside the cell to outside the cell. Once secreted into secretions, what does Cl- then do?

1 - degrades secretions such as mucus
2 - attracts H2O into secretions and thins secretions
3 - inhibits secretions
4 - all of the above

Answer 9

2 - attracts H2O into secretions and thins secretions
- leads to very thick mucosa present in the lungs, pancreas and GIT

Question 10

How can cystic fibrosis affect newborns?

1 - inhibits the closure of ductus arteriosus
2 - thickens meconium
3 - blocks oval foreman
4 - leads to blockage of portal system

Answer 10

2 - thickens meconium
- can causes a SURGICAL EMERGENCY called meconium ileus as the GIT becomes blocked

Question 11

In early childhood which of the following is most affected in cystic fibrosis?

1 - lungs
2 - GIT
3 - reproductive organs
4 - pancreas

Answer 11

4 - pancreas
- leads to pancreatic insufficiency

Question 12

In early childhood the pancreas is the most affected organ in cystic fibrosis. Thick secretions can cause what to become blocked?

1 - pancreatic duct becomes blocked
2 - 2nd part of the duodenum
3 - blockage of common bile duct
4 - blockage of terminal ileum

Answer 12

1 - pancreatic duct becomes blocked
- leads to impaired exocrine secretions
- proteins and fats cannot be absorbed

Question 13

In early childhood the pancreas is the most affected organ in cystic fibrosis. Thick secretions can cause the pancreatic duct to become blocked, reducing exocrine sections into the GIT and reducing protein and fat absorption. This can lead to all of the following, EXCEPT which one?

1 - poor weight gain
2 - failure to thrive
3 - clay-colored stools
4 - acute and chronic pancreatitis
5 - insulin dependent diabetes

Answer 13

3 - clay-colored stools
- typically causes steatorrhea

• pancreatitis is due to enzymes being trapped in pancreatic duct that begin to digest itself
• insulin dependent diabetes is a chronic effect

Question 14

In early childhood the pancreas is the most affected organ in cystic fibrosis (CF). Thick secretions can cause the pancreatic duct to become blocked, reducing exocrine sections into the GIT and reducing protein and fat absorption. This can also lead to exocrine enzymes self-digesting the pancreas causing pancreatitis, and eventually chronic pancreatitis. What can this then cause in the pancreas?

1 - pancreatomegaly
2 - ulcers
3 - fibrosis and cysts
4 - all of the above

Answer 14

3 - fibrosis and cysts
- where the name CF comes from

• cysts are fluid filled sacs wrapped in a membrane

Question 15

Later in childhood cystic fibrosis affects the lungs. What happens in the lungs?

1 - mucus becomes thick and sticky
2 - mucociliary escalator cannot move mucus towards the trachea
3 - bacteria are able to infiltrate the thick mucus and colonise the lungs
4 - all of the above

Answer 15

4 - all of the above

Question 16

Later in childhood cystic fibrosis affects the lungs, causing the following to occur:

• mucus becomes thick and sticky
• mucociliary escalator cannot move mucus towards the trachea
• bacteria are able to infiltrate the thick mucus and colonise the lungs

If the bacterial load increases sufficiently this can lead to symptoms. Which of the following is NOT a common symptom?

1 - fever
2 - cough
3 - X-ray changes on the chest
4 - increased lung function

Answer 16

4 - increased lung function
- causes a decreased lung function

• these symptoms is called a CF exacerbation and need to be treated with antibiotics

Question 17

Is cystic fibrosis a restrictive or obstructive lung disease?

Answer 17

• obstructive
• mucus plugs are formed, meaning air can enter but not leave

Question 18

Which 2 of the following are common bacteria that can cause a pneumonia and CF exacerbation?

1 - staphylococcus aureus (gram +)
2 - chlamydia psittaci
3 - pseudomonas aeruginosa (gram -)
4 - influenza virus

Answer 18

1 - staphylococcus aureus (gram +)
3 - pseudomonas aeruginosa (gram -)

• difficult to treat as bacteria can hide in mucus from antibiotics and immune system

Question 19

In cystic fibrosis (CF) patients are at increased risk of CF exacerbations due to infection which can also cause inflammation. Over time this can become chronic and lead to what?

1 - bronchiectasis
2 - asthma
3 - COPD
4 - interstitial lung fibrosis

Answer 19

1 - bronchiectasis
- bronchial walls are damaged
- bronchial walls become permanently dilated
- mucus fills bronchi causing mucus plugs

Question 20

In patients with cystic fibrosis, the bronchi can become inflamed and dilates, called bronchiectasis. If the inflammation continues this can cause what?

1 - recurrent laryngeal damage
2 - right sided heart failure
3 - gastro-oesophageal reflux disease
4 - erosion of blood vessels and haemoptysis

Answer 20

4 - erosion of blood vessels and haemoptysis
- patients can cough up blood

Question 21

Chronic cystic fibrosis (CF) exacerbations can lead to the main cause of death in patients with CF. All of the following can occur in CF patients, but what is the main cause of death in CF patients?

1 - pneumothorax
2 - cor pulmonale
3 - respiratory failure
4 - bronchiectasis

Answer 21

3 - respiratory failure

Question 22

When examining a patient with cystic fibrosis, which of the following clinical signs would we typically not find?

1 - finger clubbing
2 - fine tremor
3 - bilateral course crackles
4 - cyanosis

Answer 22

2 - fine tremor
- not common in CF

Question 23

If a patient presents to A&E with cystic fibrosis (CF) and acute abdominal pain, which of the following may be a differential which is associated with CF?

1 - pancreatitis
2 - distal intestinal obstructive syndrome (DIOS)
3 - cholecystitis (gallbladder inflammation)
4 - gastro-oesophageal reflux disease (GORD)
5 - Cystic Fibrosis Liver Disease (CFLD)
6 - colorectal cancer
7 - all of the above

Answer 23

7 - all of the above

Question 24

If a patient presents to A&E with cystic fibrosis (CF) and acute abdominal pain, which of the following is NOT a non-CF related differential that should be considered?

1 - IBS
2 - appendicitis
3 - gastritis
4 - liver cirrhosis
5 - gastroenteritis

Answer 24

4 - liver cirrhosis

Question 25

Distal intestinal obstruction syndrome (DIOS) is a complication of cystic fibrosis (CF). Here the bowel becomes partially of completely blocked due to a hard immobile mass, typically on the right side of the abdomen. What is the main cause of this?

1 - lack of peristalsis
2 - too much liquid being secreted into the lumen
3 - lack of fluid being secreted into the lumen
4 - all of the above

Answer 25

4 - all of the above
- thick “stool” blocks intestinal tube

Can be caused by:
- pancreatic insufficiency
- dehydration
- narrowing of the GIT, ileocaecal area particularly affected
- terminal ileum leads to vitamin B12 absorption
- valve dysfunction leads to “dumping” syndrome from ileum to colon
- can present like an appendicitis

Question 26

A rare complication that can occur in cystic fibrosis is when part of the bowel slides into an adjacent part of the bowel, which can be a surgical emergency. What is this called?

1 - intussusception
2 - ileus
3 - perforation
4 - volvulus

Answer 26

1 - intussusception

Question 27

How can we treat distal intestinal obstruction syndrome and/or intussusception?

1 - rehydration
2 - laxatives
3 - enzyme (Creon)
4 - surgery
5 - all of the above

Answer 27

5 - all of the above

Question 28

Cystic fibrosis (CF) can cause inflammation of the gall bladder called cholecystitis. Why does CF cause cholecystitis?

1 - CFTR is highly expressed in liver and biliary tree
2 - can lead to narrowing biliary tree or mini gall bladder
3 - bile secretions are thick and sticky and block the biliary tree
4 - all of the above

Answer 28

4 - all of the above

• increased risk from bacterial endotoxins due to lack of secretions into the duodenum

Question 29

Cystic fibrosis can cause Cholecystitis due to the high expression of the CFTR in the liver and biliary tree. This can lead to narrowing of the biliary tree or a mini gall bladder. The bile secretions can be thick and sticky, increasing the risk of gall stones and blockage of biliary tree and increase the risk of bacterial infections. What can patients with CF present with?

1 - appendicitis
2 - pancreatic cancer
3 - jaundice
4 - all of the above

Answer 29

3 - jaundice
- due to obstruction of the bile ducts

Question 30

Gastro-oesophageal reflux disease (GORD) is common in CF, affecting around 35-80% of patients. Although GORD has a number of nasty symptoms, it can also affect the lungs. How can this occur?

1 - gastric contents degrade oesophagus and get into the lungs
2 - patients aspirate gastric contents
3 - gastric secretions can damage stomach lining, leading to pleural damage
4 - all of the above

Answer 30

2 - patients aspirate gastric contents
- increases risk of infections
- can prescribe PPI to reduce risk of this

Question 31

If a patient did present with acute pancreatitis, how would they typically present?

1 - acute epigastric pain that radiates to the back
2 - raised amylase (4x normal)
3 - raised WBC
4 - steatorrhea
5 - may develop infection
6 - all of the above

Answer 31

6 - all of the above

Question 32

How can cystic fibrosis cause cystic fibrosis associated liver disease (CFLD)?

1 - thick bile acids block bile ducts
2 - highly concentrated bile can be toxic
3 - toxic biles acids can damage liver through acidification
4 - all of the above

Answer 32

4 - all of the above
- toxic bile backs up into liver and damaged bile ducts and hepatocytes

• affects around 30% of patients, more in women than men

Question 33

How can cystic fibrosis lead to colorectal cancer?

1 - chronic inflammation of the GIT leads to dysplasia
2 - mucus secretions are impaired
3 - mucous barrier is impaired
4 - all of the above

Answer 33

4 - all of the above

Question 34

The risk of colorectal cancer is increased in cystic fibrosis (CF) by 5-10%. Which of the following symptoms would CF patients NOT present with if they developed colorectal cancer?

1 - blood in stool
2 - weight loss
3 - acute appendicitis
4 - anaemia
5 - change in bowel habit

Answer 34

3 - acute appendicitis

Question 35

The risk of colorectal cancer is increased in cystic fibrosis (CF) by 5-10%. What investigations should be considered in CF patients?

1 - laparotomy
2 - faecal immune test (qFIT)
3 - colonoscopy (polyps)
4 - capsule enterography

Answer 35

1 - laparotomy

Question 36

In early childhood the pancreas is the most affected organ in cystic fibrosis. Thick secretions can the pancreatic duct to become blocked, reducing exocrine sections into the GIT and reducing protein and fat absorption. This can lead to all of the following, EXCEPT which one?

Question 37

When trying to diagnose patients with cystic fibrosis we can use the sweat test. The elevation of which ion >60mmol/L is diagnostic of CF on 2 seperate occasions. Which ion is typically elevated?

1 - Na+
2 - Cl-
3 - K+
4 - Mg2+

Answer 37

2 - Cl-
- this is because Cl- cannot be absorbed in the sweat
- Na+ will also be high, but lower than Cl-
baby can taste salty when kissing the skin

Question 38

Although sweat testing is one of the main tests to diagnose cystic fibrosis, another marker in the stool can also be used. What is measured in the stool?

1 - elastase
2 - faecal calprotectin
3 - blood
4 - amylase

Answer 38

1 - elastase
- involved in digestion
- low levels suggest pancreatic insufficiency

Question 39

Which of the following blood tests is NOT routinely performed to diagnose and monitor patients with cystic fibrosis?

1 - FBC
2 - U&Es
3 - LFTs with clotting profile
4 - vitamins ADEK
5 - q-Fit
6 - glucose tolerance test

Answer 39

5 - q-Fit

• glucose tolerance test = to monitor pancreatic secretion of insulin

Question 40

An X-ray can be performed in patients with cystic fibrosis. Would we expect to see hypo or hyper inflated lungs?

Answer 40

• hyper-inflated lungs
• this is an obstructive respiratory condition like COPD

Question 41

Which of the following are treatment that must be included in patients with cystic fibrosis (CF)?

1 - physiotherapy for lung function
2 - creon (digestive enzymes)
3 - antibiotics for CF exacerbations
4 - bronchodilators
5 -