CPS 1

Question 1

State risk factors of Cystic Fibrosis

Answer 1

1. Autosomal Recessive (patient needs to carry 2 faulty genes to have condition)- inherited
2. Rare (1/2500 incidence in UK)
3. Carrier (one faulty gene) in UK is 1/25 (if 2 carriers have children, 1/4 chance child has cf)
4. Caused by gene mutation on chromosome 7 (mutation to gene that codes for cystic fibrosis transmembrane conductance regulator protein) - MOST COMMON
5. Over 2000 other abnormal genes (not caused by just mutation to chromosome 7)

Question 2

Describe the mechanism of disease: Cystic fibrosis transmembrane regulator protein

Answer 2

1. Mutation to gene which codes for CFTR (cystic fibrosis transmembrane regulator protein)
2. CFTR facilitates movement of Cl- from epithelial cells into lumen of bowel, vas deferens, lungs + pancreas, therefore, Na+ and therefore, by process of osmosis, water. Intraluminous Mucous contains NaCl + water. Water allows mucus to move freely
3. When mutation to CFTR, no Cl- so Na+ so no water, mucus (lining epithelial surfaces of lungs, pancreas etc) becomes dehydrated, therefore, thick, , cannot move freely, difficult to clear - in lungs causes chest infections - in pancreas by blocking ducts - in vas deferens blocks ducts
4. In sweat glands: reduction of facilitated movement of Cl- from sweat back into sweat glands - sweat rich in content of Cl- + Na+ so its salty (DIAGNOSIS)

Question 3

Defence mechanisms of respiratory tract

Answer 3

1. Nose hairs + mucus: catch bacteria + virus particles going any further (smaller particles bypass this + go further into lungs)
2. Mucous lines inside of bronchi + bronchioles: traps smaller particles which bypass into lungs
3. Mucociliary escalator (cillia, tiny hairs, act in unison): Clears mucous that lines bronchi + bronchioles which trapped smaller particles. Mucus eventually brought to back of throat, swallowed down / spat out

Question 4

Describe how CF affects respiratory system

Answer 4

Affects defence mechanisms of respiratory tract:

1. In CF, mucous lining respiratory tract dehydrated, thick, viscid. Therefore, cannot move well. Cillia cannot sweep the thick mucous. Affects mucociliary escalator
2. Therefore, build up of mucous with pathogens inside
3. Leads to recurrent infections - initially common pathogens, but takes longer to recover, then infections with unusual organisms (e.g. staphylococcus aureus)
4. Gradual damage to lungs with loss of lung function

This all results in a productive cough (wheezing)

this info can help us diagnose a patient with CF, unusual for colds to constantly occur

Question 5

Describe how CF affects GI system + nutrition

Answer 5

1. CF leads to blockage of pancreatic ducts (because exocrine secretions contain too little water, they become thickened)
2. Damage to exocrine pancreas (exocrine pancreas becomes painfully inflamed - pancreatitis + fibrotic) (The exocrine pancreas normally releases lots of enzymes involved in digestion + absorption)
3. Reduced digestion + absorption of food (because the gut
4. Leads to steatorrhoea (fatty, loose pale frequent stools)
5. Therefore, increased nutritional requirement (because patient will not be absorbing fat, protein and carbs well)
6. Therefore, poor weight gain (useful for diagnosis)

ADD NOTES FROM IMAGE

Question 6

Describe how CF affects endocrine system

Answer 6

1. CF leads to blockage of pancreatic ducts
2. Damage to endocrine pancreas (involved in glucose control)
3. Damage + loss of insulin producing cells
4. Diabetes can occur in CF patients

Question 7

Describe how CF affects reproductive system

Answer 7

1. CF leads to blockage of vas deferens, so failure of development of vas deferens
2. Male infertility
3. Delay in puberty

Question 8

How can CF affect patient psychologically

Answer 8

1. Long term deteriorating disease with shortening life expectancy
2. Recurrent hospital admission
3. Affect patient + family (impact on family greater when patient is child)

Question 9

How does CF affect patient socially?

Answer 9

Social issues
Loss of school / work issues
Finances
Cost to patient / family / hospital / country

Question 10

Treatments for CF patients: Pharmacology and CF patients

Answer 10

1. Antibiotics
2. Bronchodilators
3. Pancreatic supplement (enzymes to aid digestion + absorption of food)
4. Insulin
5. Vitamins ADEK

Question 11

Describe the MDT involved in treating a CF patient

Answer 11

1. Physiotherapy
2. Nutritional support - dieticians
3. Respiratory support
4. Microbiologists
5. Surgery
6. Lung Transplants
7. Psychology
8. Social care

Question 12

Describe diagnostic services for CF patients

Answer 12

1. Sweat test -
2. Genetic testing
3. Radiology
4. Laboratory services

Question 13

What healthcare systems have been put in place to diagnose CF more efficiently

Answer 13

1. Neonatal screening introduced (screening after birth, within first 28 days)
2. Common disease. 1/2500 births in UK
3. starting therapies earlier aids long term management of CF

Question 14

Cystic Fibrosis notes from TOB L2.2

Answer 14