Cystic Fibrosis in Children and Adults Flashcards
Is cystic fibrosis dominant or recessive?
Recessive
How do you get a recessive disease like CF?
Inheriting two copies of the mutated gene, one from each parent.
In which group is CF the most common autosomal recessive disorder?
Caucasians (white people)
How many people are carriers of CF?
1in 25
What is the most common mutation seen in CF patients?
Delta 508
What is the main cause of morbidity and mortality in those with CF?
Pulmonary disease
What % of deaths in those w CF is due to respiratory failure?
90%
If both parents are affected, what are the chances the child will be affected?
1 in 4
25%
If both parents are affected, what is the chance the child will be a carrier?
2 in 4
50%
If both parents are affected, what is the chance that the child will be unaffected?
1 in 4
25%
What is the chromone pair which CF affects?
Chromosome pair 7
Which protein does the mutation occur?
Transmembrane conductance regulator protein
What happens to the cell due to abnormal function of the protein channel?
Chloride is trapped in the cell. Sodium and water then follow chloride and flow into the cell
What can the abnormal chlorine and sodium transport cause to happen?
Dehydrates mucous layer meaning reduced airway liquid
Thick sticky mucous forms
How does the abnormal chlorine and sodium transport affect bacteria levels?
There will be impaired bacteria killing via neutrophils
How many mutation classes are there for CF?
6
Which mutation classes cause the more severe cases of CF?
Classes 1-3 due to no functioning protein
Which mutation classes cause the milder CF?
Classes 4-6 due to some functioning protein
If there is identification of a parent/sibling with CF, which antenatal tests can be done to test if the developing child has CF?
Pre-implantation genetic diagnosis
Chorionic villous sampling
Amniocentesis
Which test can be used to test the baby for CF after birth?
Newborn bloodspot day 5 (Guthrie test)
What can you test anytime postnatally to test for CF?
Sweat
Describe why sweat is tested for CF.
Measure the chlorine conc. in sweat and will be elevated in those with CF
Name the three outcomes of the combination of prenatal, antenatal and postnatal testing can give.
Have CF
Don’t have CF
Screen positive inconclusive diagnosis
Which systems of the body can CF affect?
Any system of the body
Name some of the main conditions which may indicated CF.
Pancreatic insufficiency
Diabetes
Infection and bronchiectasis
What organ does the CFTR also affect?
The pancreas
What effect does the CFTR mutation have on the pancreas?
Lack of enzymes to digest food hence leading to:
Malabsorption
Abnormal stools - pale, offensive, float
Failure to thrive
Classes 1-3 have what effect on the pancreas?
Pancreas is inefficient
Classes 4-6 have what effect on the pancreas?
Pancreas has some function
What can recurrent bronchopulmonary (chest) infection cause?
Pneumonia
Bronchiectasis
Scarring
Abscesses
List the reasons pulmonary infection may occur due to the CFTR abnormality.
-Abnormal electrolyte transport across cell membrane
-Dehydration of airway surface layer (water later which allows mucous to slide easily up airway to be coughed up)
-Decrease in mucociliary clearance
-Mucous sticks to mucosal surface
-Increased access to bacteria
-Decreased bacteria killing
What can mucous sticking to the mucosal surface do?
Causes shearing and inflammation
Discuss the cycle of events which lead to repeated respiratory infections.
Firstly, I am sorry but if you read through, it makes sense! Got a lot of words :/
- Decreased mucus clearance, increase in bacteria adherence and a decrease in the endocytosis of bacteria
- This leads to bacteria colonisation
- This leads to inflammation, mucus plugging, airway ulceration and damage.
- This leads to bronchiectasis
and so the cycle continues xoxoxoxo
What is the result of recurrent chest infections?
Progressive respiratory decline
Which investigations can be used to diagnose CF?
CXR usually not enough alone so CT too
What is meant by tramlines?
Thickened dilated airways that cannot clear mucus, often seen on CT in those w CF.
What would you see on a CT in those with CF?
Tramlines
Signet rings
Mucous plugging
Consolidation (infection)
What is the treatment for pancreatic insufficiency in CF?
Boosting nutrition
In terms of nutrition, what will be done in those with pancreatic insufficiency?
- Replace enzymes
- High energy plus high calorie supplement drinks
- Fat-soluble vitamin and mineral supplements
What is the treatment for mucus obstruction and inflammation?
-Airway clearance via physiotherapy
-Mucolytics
-Bronchodilators
What is the treatment for chronic infection?
-Antibiotics, either oral, IV or nebulised
Which antibiotic can be given to treat inflammation?
Azithromycin
What management is provided for those with fibrosis/scarring/bronchiectasis?
Supportive treatment and management of symptoms
The treatment in which condition differs in those with CF and those without CF?
Diabetes
List some of the diabetic issues present in those with CF.
Compliance with diet a problem- need high calorie diet (unlike non CF diabetics)
Insulin of benefit, not so much oral drugs
Complication risk same as non CF pts but lung disease gets there first
What can happen to the bones in patients with CF?
Bone mineral density (BMD) falls increasing risks of osteoporosis
What are some of the treatment options for patients with osteoporosis and CF?
Bone protection drugs, weight bearing exercise
What may happen in the lungs of those with CF?
Pneumothorax
Why may there by haemoptysis in CF?
Bronchial wall destruction may cause patients to cough up blood
What do modulator drugs do in those with CF?
Address different parts of CFTR production, processing, folding, transport and insertion into the membrane.
What are the benefits in modulator drugs in those with CF?
Small benefits in lung function.
More significant benefit is fall in chest exacerbations, rise in weight and improved QOL.
When might you get a double lung transplantation?
Rapidly deteriorating lung function
FEV1 < 30% predicted
Life threatening exacerbations
Estimated survival <2 years
Recurrent pneumothorax, recurrent severe haemoptysis
List some reasons a patient not be referred for a lung transplant.
Other organ failure
Malignancy within 5 years
Significant peripheral vascular disease
Drug, niotine, alcohol dependency
Why have CF survival rates improved?
CF centres
MDT teams
Physiotherapy
Nutrition/Enzymes
Antibiotics
Aggressive approaches
Annual flu/pnemococcal vaccines
