Cystic fibrosis

Question 1

What type of genetic inheritance is observed in CF?

Answer 1

Autosomal recessive

Question 2

What is the gene and its pre

product ?

Answer 2

Cystic fibrosis transmembrane conductor regulator (Cl from inside to extracellular space), Cl channel

Question 3

What is the commonest mutation in CF?

Answer 3

Phe508del

Question 4

What are the 5 classes of mutations?

Answer 4

Class 1 stop mutation, class 2 abnormal RNA, class 3 protein does not open, class 4 decreased conductance, class 5 decreased abundance

Question 5

What is the pathology of CF?

Answer 5

Cl- ions regulate the amount of fluid, in CF there is less fluid and cilia collapse, mucus builds up and inflammation results, damage of the airways, ulceration

Question 6

What are the signs ?

Answer 6

Most commonly recurrent chest infections, depends on age, in older kids nasal polyps, sinusitis, male infertility

Question 7

What is the screening test for CF?

Answer 7

Guthrie test to test for immune reactive trypsinogen, of positive mutation analysis and sweat test

Question 8

What is the first cardinal sign of CF?

Answer 8

Abnormal stools, pancreatic insufficiency, pale, orange and offensive stools, greasy and oily, fat malabsorption, also possible deficiency of fat soluble vitamins

Question 9

How can be the first cardinal sign of CF treated?

Answer 9

Entirely coated tablets that contain pancreatic enzymes, fat soluble vitamins and minerals supplements, promote pump inhibitors and H2 antagonist to improve tablets delivery to stomach

Question 10

What is the second cardinal sign of CF?

Answer 10

recurrent chest infections such as pneumonia, bronchiectasis, pneumothorax, haemoptysis, respiraoty failure, cor pulmonale

Question 11

What is the treatment of the second cardinal sign?

Answer 11

Mycolytics (hypertonic saline or DNase), infection control measures, physiotherapy to improve airways clearance (percussion and drainage, active cycle breathing, autogenic drainage) adjuvants (positive expiratory pressure mask), prophylactic antibiotics, vaccinations, eradication of the infection early and vigorously

Question 12

What are the bacteria that commonly infect patients with CF?

Answer 12

Staph aureus, Heamophilus influenzae, Pseudomonas aeruginosa

Question 13

What are the less common bacteria affecting CF patients?

Answer 13

Burkholderia cepacia, Stenotrophominas maltophilia, Mycobacterium abscessus

Question 14

What are other possible manifestations of CF in GI?

Answer 14

dysmotility, meconium ileum, gastro-oesophageal reflux, distal intestinal obstruction, constipation, rectal prolapse, crohn disease

Question 15

What other possible manifestations are there ?

Answer 15

hepatopathy, upper aiway polyps, sinusitis, diabetes, bone osteoporosis, arthropathy, bilateral absence of vas deferens, vaginal candidiasis, hypertrophic pulmonary osteoarthropathy

Question 16

What are the signs of CF?

Answer 16

Cyanosis, bilateral coarse crackles, fingers clubbing

Question 17

Patients with CF get infected with only certain bacteria , true of false?

Answer 17

True

Question 18

Describe hos Pseudomonas aeruginosa infects the CF patients?

Answer 18

CFTR plays a role in endocytosis and destruction, once in lungs bacteria undergo mucoid change, biofilm on micro colonies is formed. This is protective layer, hard for immune cells antibiotics to get in. Bacteria readily exchange information between each other and acquire resistance. Immune cells fail to fight, free radicals are produced and the tissue is damaged.

Question 19

What is the treatment for pseudomonas aeruginosa?

Answer 19

oral ciprofloxacin and nebuliser colomycin

Question 20

Describe the infection with Bukholderia cepacia

Answer 20

environmental organism, innate resistance to most antibiotics, rapid decline in lung function, cepacia syndrome -aggressive, hyperactive patients

Question 21

Describe the infection with Stenotrophomonas maltophilia

Answer 21

Occurs usually after pseudomonas, resistant to multiple antibiotics

Question 22

Describe the infection with Mycobacterium abscessus

Answer 22

Increase in numbers, resistant to all anti-TB treatments, abscesses, lung transplant

Question 23

What is the treatment of these infections?

Answer 23

Early and aggressive treatment, oral for Staph, Heamophilus, Pneumococcus, IV for pseudomonas and burkholderia, two antibiotics beta lactams and animo glycosides, large dose, two weeks usually

Question 24

What is ivacafor?

Answer 24

Drug that binds to CFTR, improves Cl ion transfer and lung function

Question 25

When are patients considered for lung transplant?

Answer 25

When FEV1 is less than 30 % predicted, life threatening exacerbations, rapidly deteriorating

Question 26

What are the contra-indications for lung transplant ?

Answer 26

Malignancy, organ failure, significant vascular disease, drugs, nicotine, alcohol dependency, active systemic infection, microbiological issues