Cystic Fibrosis Flashcards
Where is the CF gene located?
long arm of chromosome 7
What is the most common defect in CF patients?
Delta 508 (3 nucleotide deletion, loss of phenylalanine)
Which genetic mutation do we have medication for?
G551 D
Where is CFTR protein located?
plasma membrane of epithelial cells lining: lung, panc, intestines, GB, liver, kidney, salivary/sweat glands, epidydmis
Class I CFTR mutation is?
premature stop codon! defective protein production so decreased quantity
Class II CFTR mutation is in processing and trafficking… explain
deletion of aa causes improper folding of the polypeptide. Leads to abnormal interactions with chaperone proteins in ER and degradation in ER so the protein does not arrive at the apical membrane!
Which CFTR mutation is there medication that can modify function?
Class III defective cAMP regulation of the CFTR… gating abnormality! So, meds attach and enhance the channel activity! potentiator!
What three processes contribute to mechanical clearance of the lung?
ion transport systems (in airway epithelium), secreted products (mucins), ciliary beating
What are the three ion transport systems located in the apical airway epithelium?
ENaC, CFTR, CACC (Ca activated CL- channel)
What is one of the CFTR modifying genes that cause wide spectrum of phenotypes?
Transforming Growth Factor-Beta 1
What are the most important bacterial infections with CF lung disease?
staph aureus and pseudomonas aeruginosa
What are some characteristic radiologic features of CF?
Tram Tracks (thick dilated airway and mucus block), pleural line separating lung from air
What agents work to change the viscosity of mucous?
Dornase Alfa (rhDNase, pulmozyne) lyse dead inflamm cells so it's easier to cough out the mucus! hypertopic saline to hydrate the mucus
What role does azythromycin play in CF therapy?
Improves lung function and decreases exacerbations by working as anti-inflammatory agent. not for antibiotics!
How successful are lung transplants in CF patients?
VERY!!! best!! because patients are younger and have fewer comorbidities
Why are CF patients predisposed to diabetes?
Their digestive enzymes cannot get out of the pancreas because ducts are clogged. SO, the enzymes digest the pancreas! leads to diabetes
What are a CF patient’s clinical manifestations of Pancreatic/GI disease?
Large, fatty, greasy stools! poor weight gain!
Diet advice for CF?
High caloric, high fat diet because they need to gain wait! also malabsoprtion of fat soluble vitamins so give supplements. nutritional support!
How can we treat CF pancreatic disease?
enzyme replacement therapy, suppress gastric acid secretion (helps enzymes work better)
How do we diagnose CF?
Sweat chloride measurement- pilocarpine iontophoresis method- IRT test or genetic test
What are the criteria for diagnosing CF?
2 known CF causing mutations OR any of the following plus 2 sweat chloride levels great than 60 : family history, positive newborn screening test, typical symptoms
