Cystic fibrosis + bronchiectasis

Question 1

List the 3 cardinal symptoms of CF

Answer 1

• elevated sweat chloride levels
• persistent pulmonary infection
• pancreatic insufficiency

Question 2

What is the likely pattern on RFTs for a patient with CF?

Answer 2

obstructive picture

Question 3

Describe the findings of this CT chest taken from a patient with CF

Answer 3

• mucous plugging
• centrilobular nodules
• peribronchial thickening
• brochiectasis

Question 4

There are multiple drugs that function as CFTR modulators. What is the role of Ivactor

Answer 4

opens the channel of the protein

Question 5

There are multiple drugs that function as CFTR modulators. What is the role of Tezacaftor?

Answer 5

moves the protein to the cell surface by CORRECTING MISFOLDING
*elexacaftor also does this

Question 6

Outline what the treatments are for airway clearance therapies in CF

Answer 6

• DNAse
• hypertonic saline
• mannitol
  *CFTR modulators also have a role to play

Question 7

What antibiotic and class is used to treat chronic pseudomonas infection among patients with CF?

Answer 7

azithromycin
*check QTc interval

Question 8

Outline how to test pancreatic insufficiency in a patient with CF

Answer 8

> stetorrhea, failure to thrive, malabsorption
malabsorbtion of fat soluble proteins (A, D, E, K)
test faecal elastase (would be reduced as not being produced by the pancreas)
check for improvement with pancreatic enzyme replacement therapy

Question 9

What is the cause of infertility in CF?

Answer 9

due to a CFTR mutation causing congenitial abscence of the Vas defrens and this leads to obstructive azoospermia (most common cause of congentiial abscence of the Vas defrens)

Able to create sperm but unable to transport them appropriately. The semen does not contain sperm, this is known as azoospermia

Question 10

list one diagnostic criteria for CF

Answer 10

• Clinical symptoms consistent with CF OR +ve newborn screening OR having a sibling with CF
• Evidence of CFTR dysfunction
  > Elevated sweat chloride >60
  > 2 disease causing mutations in the CF gene
  > Abnormal NPD (nasal potential difference)

Question 11

What is the most common mutation associated with CF?

Answer 11

F508del

Question 12

List 5 causes of bronchectasis

Answer 12

• Young syndrome – bronchiectasis, sinusitis and obstructive azoospermia without CF
• RA & Sjogrens disease can be complicated by bronchiectasis
• Primary ciliary dyskinesia
• Mycobacteria infections

Question 13

Describe what Young syndrome is

Answer 13

bronchiectasis, sinusitis and obstructive azoospermia without CF

Question 14

In 3-4 sentences, describe the pathophysiology of bronchiectasis

Answer 14

• Induced by an infective insult and impaired drainage/airway obstruction/defect in host defence
• Important contributing factors
  > Excessive neutrophilic response
  > Concentrated sputum
  > Atopy (excluding individuals with ABPA)
  > CFTR heterozygous variants
  > Vitamin D deficiency
  > CVID
• Worse outcomes if colonised pseudomonas

Question 15

What is the cardinal symptom of bronchiectasis?

Answer 15

cough with tenacious sputum for multiple days of week for months to years
*consider increased risk with a Hx of exacerbations

Question 16

What is the imaging modality that allows a definitive method of Dx of bronchiectasis?

Answer 16

Non-contrast CT chest

Question 17

Describe the expected CT findings for a patient with bronchiectasis

Answer 17

 Airway-to-arterial ratio >1.5
 Lack of tapering of bronchi
 Airway visibility within 1 cm of a costal pleural surface or touching the mediastinal pleura

Question 18

What would be the expected distribution of bronchiectasis in a patient with ABPA?

Answer 18

centra (perihilar) distribution

Question 19

What would be the expected distribution of bronchiectasis in a patient with CF?

Answer 19

predominant upper long distribution

Question 20

A patient has idiopathic bronchiectasis. Where might the illness be distributed on CT chest?

Answer 20

lower lobe predominance

Question 21

List 3 organisms associated with bronchiectasis

Answer 21

• Psuedomonas
• Aspergillis
• Staph aureus
• Stenotrophomonas maltophilia

Question 22

A patient has psueodomonas during an admission to hospital on a b/g of bronchiectasis. What Abx would you prescribe?

Answer 22

Ciprofloxaxin (usually ~10 day course)