Cystic Fibrosis

Question 1

How many live births does cystic fibrosis affect

Answer 1

1 in 2500

Question 2

How is cystic fibrosis inherited

Answer 2

in an autosomal recessive manner

Question 3

How much of the population are carriers for the disease

Answer 3

1 in 25

Question 4

Where is the mutational defect that causes cystic fibrosis

Answer 4

On the long arm of chromosome 7 that codes for (CFTR)

Question 5

What does CFTR stand for

Answer 5

Cystic Fibrosis Transmembrane conductance regulator

Question 6

What is the most common mutation

Answer 6

Deletion of three base pairs of the gene results in the loss of phenylalanine at position 508

Question 7

What is the primary physiological defect in cystic fibrosis

Answer 7

Reduced chloride conductance at epthelial embranes

Question 8

What is a characteristic of the disease

Answer 8

Chloride and sodium in the sweat (salty sweat)

Question 9

How many classes of mutations of the CFTR gene are there

Answer 9

5

Question 10

Mutations in classes 1-3 result in what

Answer 10

No CFTR function at the cell membrane

Question 11

What is more severe? classes 1-3 or classes 4-5

Answer 11

Classes 1-3

Question 12

What does reduced chloride secretion and increased sodium reabsorption result in in the bronchial mucosa

Answer 12

Secretions of abnormal viscosity with reduced water content of the airway surface liquid and reduced depth of the periciliary fluid

Question 13

What inactivates defensins

Answer 13

The high salt content of the airway surface

Question 14

What inactivates defensins

Answer 14

The high salt content of the airway surface

Question 15

What are defensins

Answer 15

Naturally occurring antimicrobial peptides on the epithelial surface

Question 16

Why does bacteria adhere to the mucosa and proliferate in patients with cystic fibrosis

Answer 16

These patients have abnormal mucus glycoproteins that act as binding sites for the bacteria

Question 17

In what organ is there abdnormal ion transport resulting in plugging and obstruction of ductules with pregressive destruction of the gland

Answer 17

Pancreas

Question 18

Why does malabsorption occur in patients with cystic fibrosis

Answer 18

Pancreatic enzymes fail to reach the small intestine which results in malabsorption off fats with steathorrhoea and failure to gain weight

Question 19

What might cause diabetes in a patient with cystic fibrosis

Answer 19

Progressive destruciton of the endocrine pancreas

Question 20

Why do patients with cystic fibrosis have an increased incidence of fallstones and biliary cirrhosis

Answer 20

Abnormalities of bile secretion and absorption

Question 21

10% of children with cystic fibrosis present with what at birth

Answer 21

Meconium ileus

Question 22

What is meconium ileus

Answer 22

A form of intestinal obstruction caused by inspissated viscid faecal material resulting from lack of pancreatic enzymes and from reduced intestinal water secretion

Question 23

What are other symptoms of cystic fibrosis

Answer 23

obvious malabsorption by the age of 6 month (50%0
failure to thrive
abdominal distension
copious offensive stools from steatorrhoea
Rectal prolapse occasionally occurs

Question 24

What is the most prominent feature of cystic fibrosis

Answer 24

Recurrent respiratory infections with cough, sputum production and wheeze

Question 25

What is the most prominent feature of cystic fibrosis

Answer 25

Recurrent respiratory infections with cough, sputum production and wheeze

Question 26

What are the typical organisms isolated in sputum cultures

Answer 26

Staph Aureus Haemophilus influenzae Streptococcus pneumoniae

Question 27

By the teenage years, many patients will have become infected with what?

Answer 27

Mucoid strains of pseudomonas aerginosa

Question 28

What organism causes onion rot

Answer 28

Burkholderia cepacia complex

Question 29

How can burkholderia cepacia complex spread

Answer 29

From person to person in close social contact (those with CF)

Question 30

What type of Burkholderia cepacia is associated with the worst prognosis

Answer 30

Type 3

Question 31

Why is social contact between patients with CF discouraged

Answer 31

Because of the potential for transmission of infection between patients

Question 32

What happens as the cycle of infection and inflammation progress

Answer 32

Lung damage worsens with deteriorating airways obstruction, destruction of lung parenchyma, impairment of gas exchange and the development of hypoxaemia, hypercapnia and cor pulmonale

Question 33

What provokes hypertrophy of the bronchial arteries and what does this result in

Answer 33

Persistent pulmonary inflammation | Haemoptysis

Question 34

What are some of the GI complications that patients with CF can develop

Answer 34

``` Fatty liver gallstones focal biliary fibrosis multinodular cirrhosis and hepatosplenomegaly portal hypertension oesophageal varices liver failure ```

Question 35

What is the equivalent of meconium ileus

Answer 35

Distal intestinal obstruction syndrome

Question 36

Where is there often a palpable mass (GI) in patients with CF

Answer 36

Right ileac fossa

Question 37

What is the treatment to prevent recurrence of GI symptoms

Answer 37

Pancreatic enzyme supplements, avoidance of dehydration and possible use of laxatives

Question 38

What specifically causes almost all male CF patients to be infertile

Answer 38

The congenital bilateral absence of the vas deferens

Question 39

What are CF patients at risk of developing in hot weather and why

Answer 39

Heat prostration | As a result of excess loss of salt in sweat

Question 40

How is the diagnosis of CF based upon

Answer 40

The demonstration of elevated sweat chloride concentrations on a sweat test in association with characteristic clinical features such as recurrent respiratory infections or pancreatic insufficiency

Question 41

What are the two known cystic fibrosis mutations on DNA analysis

Answer 41

Delta F508 and G542X

Question 42

What is sweating induced by

Answer 42

Pilocarpine iontophoresis

Question 43

How is the sweat test carried out

Answer 43

Pilocarpine is placed on the skin of the forearm and a small electrical current is passed across it to enhance its penetration of the skin and stimulation of the sweat ducts.

Question 44

What have the sweat chloride levels got to be above for a high suspicion of CF

Answer 44

over 60mmol/L

Question 45

What is used to detect carrier status

Answer 45

Genotyping

Question 46

What do infants with CF have

Answer 46

Elevated serum immunoreactive trypsin activity

Question 47

How is newborn screening for CF carried out

Answer 47

Measured on a single dried blood spot obtained on a Guthrie card as part of the newborn screening programme for diseases such as PKU and hypothyroidism

Question 48

What are the 4 basic elements to treatment for CF

Answer 48

Chest physio - to clear the bronchial secretions Antibiotics to treat the pulmonary infection Pancreatic enzyme supplements to correct the nutritional deficits Dietary support

Question 49

At what stage of the disease is chest physiotherapy important

Answer 49

All stages

Question 50

What 3 techniques are used during chest physio

Answer 50

Postural drainage Chest percussion Positive expiratory pressure devices

Question 51

What is given long term from early childhood?

Answer 51

Flucloxacillin

Question 52

What is the usual antibiotic used to treat exacerbations

Answer 52

Amoxicillin

Question 53

Some patients have a reversible component to their airways obstruction and benefit from what

Answer 53

Bronchodilator drugs (salbutamol) and inhaled steroids (beclametasone)

Question 54

How is mucolytic medication administered

Answer 54

By nebulisation and improves the lung function and reduces the number of exacerbations in some patients

Question 55

How is mannitol administered

Answer 55

A dry powder inhalor

Question 56

How does mannitol work

Answer 56

It is an osmotic agent that also increases the warter content of the airway surface liquid with improved mucociliary clearance

Question 57

What might be useful in reducing lung injury by inhibiting the migration and activation of neutrophils

Answer 57

High dose ibuprofen

Question 58

When are pancreatic enzyme supplements taken

Answer 58

With each meal and with snacks containing fat

Question 59

Patients with CF required how much of the recommended daily calorie intake for individuals without CF

Answer 59

120-150%

Question 60

An FEV1 of less than 30% of the predicted value is associated with what kind of mortality rate

Answer 60

50% 2 year mortality rate

Question 61

What is the main option to be considered in patients with advanced disease

Answer 61

Lung transplantation

Question 62

What is the median survival for CF patients nowadays

Answer 62

38 years

Question 63

What social factors are also affected through the illness

Answer 63

``` Reduced life expectancy Insurance choice of career relationships marriage pregnancy fertility ```