Cystic Fibrosis Flashcards
How many people in the population carry the CF gene?
1 in 25
What is the job of the CFTR protein?
Part of ion channel which moves Cl- across epithelial membrane
- also influences movement of Na+ and H2O across membrane
What happens if the CFTR protein is missing?
Ion channels cant exchange Na+ and Cl-
=> these form salt (NaCl) in the epithelium
=> H2O moves out and secretions are altered
What are the consequences of having altered secretions in CF?
- Salty Sweat
- Intestinal Blockage
- Fibrotic Pancreas
- Failure to Thrive
- Recurrent Bacterial Lung Infections
- Congenital Bilateral Absence of Vas Deferens
- Filled Sinuses
- Gallbladder and Liver disease
Different CF mutations cause different biological phenotypes. TRUE/FALSE?
TRUE
- Biological phenotypes are Graded I-V with I being the most severely affected
- Grade I mutations cause no CFTR protein to be produced
- Grade V` cause reduced transcription and synthesis of CFTR (=> still have some CFTR function)
GIve examples of common mutations found in patients with CF
F508Del
- Deletion of Phenylalanine
- @ Position 508
- seen in 70%
G551D
- Changes Glycine to Asparagine
- @ amino acid 551
- seen in 4-6%
As CF is autosomal recessive, the two genes do not need to have the same mutation present for the patient to develop CF. TRUE/FALSE?
TRUE
- different mutations in each inherited gene still cause CF
Patients with CF can have normal lung function at diagnosis. TRUE/FALSE?
TRUE
- presenting complaint may only be recurrent infection etc
If a CF patient develops pseudomonas, they require extensive antibiotic treatment. TRUE/FALSE?
TRUE
- Oral Azithromycin
- Nebulised Colomycin
- Nebulised Tobramycin
- Nebulised Aztreonam
- Inhaled Tobramycin
What happens when CF impairs the exocrine function of the pancreas? What treatments are given for this?
- Sludged up ducts
- Failure of secretion of lipases, amylase
- Digestive failure
=> Patients given pancreatic enzyme replacement (CREON)
What happens when CF impairs the endocrine function of the pancreas? What treatments are used for this?
- Destruction of pancreatic islet cells
- Fatty replacement of pancreatic tissue
=> Insulin Tx required
=> OGTT completed regularly
Why do patients with CF experience intestinal obstruction?
- Thick mucus blocks up the large and small intestine
- Symptoms similar to constipation
How is intestinal obstruction treated and prevented?
Tx:
- Gastrograffin (laxative dye used during radiology scans)
- Laxido
- Fluids
(latter 2 used for prevention also)
How does CF affect the liver?
- Sludging up of hepatic ducts
- Portal hypertension
=> anastomoses overwhelmed
=> varices can bleed
=> hepatic encephalopathy
How is portal hypertension treated?
TIPSS Procedure
- (transjugular intrahepatic portosystemic shunt)
- this procedure may increase encephalopathy risk
