CF aetiology and pathology Flashcards
what is the choride channel activated by?
ATP
which cells is it present in?
every body cells and especially cells with a lumen - like the gut, airway and pancreatic duct
there are 25 different chloride channel pumps, what is the major one?
CFTR
what does this pump do?
pumps chloride out and sodium out
what happens if the pump doesnt work?
chloride cannot be pumped out and so sodium is pumped in larger quantities to maintain the charge balance
what happens as a result of the increase in sodium ?
water follows the sodium and dries out the lumen
what is the CF cascade?
CFTR DNA mutation
CFTR protein incorrect
ion transport
altered secretions
blocked ducts and impaired mucosal defence
infection and inflammation
cystic fibrosis
what are the consequences of 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
what is the most common mutation. There are 100 different mutations that code for defects in CFTR
F508 is the major one
what are the features of class 1 CF?
no CFTR produced at all - most will die in utero
what are the features of class 2 CF?
The protein is made but is an abnormal shape so cannot get the the epithelial bed and open
they tend to have more severe disease
what are the features of class 3 CF?
The channel is made in the nucleus, embeds in the wall but doesn’t open properly
looks like it would be normal but not
what are the features of class 4 CF?
protein is made, embeds and opens but only partially
what are the features of class CF?
protein is made but not enough
why is the diagnosis of CF more common now?
because we know the range of mutations
