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Flashcards in Cystic Fibrosis Vignette Deck (15)
1

1. Describe the genetics and underlying protein defect in Cystic Fibrosis (CF).
2. Describe current understanding of pathophysiology underlying CF lung disease.
3. Describe the diagnostic and therapeutic approaches in CF.

x

2

Cystic Fibrosis (CF) is an ______ condition that results in a syndrome of chronic sinopulmonary infections and nutritional abnormalities secondary to malabsorption.

autosomal recessive

3

CF is caused by a defect in an ATP-binding cassette transporter gene on chromosome 7 that encodes for the CF Transmembrane Conductance Regulator (CFTR) protein. The most common mutation is the:

F508del, although approximately 1500 other disease-causing mutations in the CF gene have been identified. CF gene is a large gene on chromosome 7

4

Types of CF mutations:
I
II
III
IV
V

Types of CF mutations:
I - No synthesis (nonsense mutation)
II - Block in processing (F508 deletion)
III - Block in regulation (missense)
IV - Altered conductance (missense)
V - Reduced synthesis (missense)

5

Typical features of CF:

 Greasy, bulky, malodorous stools; failure to thrive due to exocrine pancreatic insufficiency
 Recurrent respiratory infections with opportunistic bacteria (e.g. Staphylococcus aureus,
Pseudomonas aeruginosa and Burkholderia cepacia)
 Chronic sinus infections
 Digital clubbing on examination.
 Bronchiectasis
 Sweat chloride > 60 mmol/L.

6

CF newborn screening Immunoreactive trypsinogen

false negative rate ranges from 1-5%) may present with clinical symptoms later in life.

7

Pancreatic insufficiency occurs in more than ___% of persons with CF.

85

8

Approximately 15% of newborns with CF present at birth with _____.

meconium ileus

[a severe intestinal obstruction resulting from inspissation of tenacious meconium in the terminal ileum.]

9

From a respiratory standpoint, clinical manifestations include

productive cough, wheezing, chronic bronchitis and recurrent pneumonias, progressive obstructive airways disease, exercise intolerance, dyspnea, and hemoptysis.

10

Chronic airway infection with bacteria, including ____ and _____, often begins in the first few months of life, even in asymptomatic infants. Eventually, _____ becomes the predominant pathogen.

S aureus and H influenzae; Pseudomonas aeruginosa

[Acquisition of the characteristic mucoid Pseudomonas is associated with a more rapid decline in pulmonary function. Chronic infection leads to airflow obstruction and progressive airway and lung destruction resulting in bronchiectasis.]

11

Treatment: pancreatic insufficiency

Enzyme replacement
High fat/protein/calorie diet
Vitamin supplements
Daily salt supplement

12

Treatment: airway/lungs

Daily percussion
Inhaled antibiotics (tobramycin (TOBI) aztreonam(Cayston)
Recombinant human DNAse (Pulmozyme - mucolytic agent)
Inhaled hypertonic saline
bronchodilators

13

Anti-inflammatory treatments

ibuprofen
azithromycin

14

CFTR modulators
Ivacaftor (CFTR potentiator)

G551D mutation or gating mutation. Must be older than 6

15

End stage lung disease symptoms?

mucus plugging, bronchiectasis, inflammation, infection