20. Cystic Fibrosis Flashcards
what is the predicted survival time for CF?
41.1 yrs
what is the CFTR, what does it do?
Conducts Cl- across the cell membrane.
Sweat gland: how is Na normally reabsorbed? how does an abnormal CFTR change this?
Sweat gland: Na normally reabsorbed after Cl is absorbed via CFTR. abnormal CFTR means that neither is reabsorbed. reason for salty sweat.
airway: how does the CFTR normally function? how does an abnormal CFTR change this?
normally, Na is reabsorbed through another channel and Cl follows. If CFTR is broken, other Cl channels increase activity yielding increase in Na coming through to interstitium from airway. Incr reabsorption of Na, Cl and airway desiccation, with thick mucus.
do you have to have full CFTR activity to be non-symptomatic?
no, doesn’t take much CFTR activity to have a normal phenotype
two categories of new therapies?
- correctors
- potentiators
what do correctors do?
increase the production of normal CFTR
what do potentiators do?
upregulate function of existing CFTR channels. basically bind to channel and keep it open.
what are the pulm complications of CF?
obstructive lung disease/bronchieactasis bact colonization hemoptysis pnemonia mycobacterial infection
what is the phenotype of bronchieactasis in CF?
loss of lung volume, trachial deviation
hemoptysis: secondary to what in CF setting?
usually secondary to progressive bronchiectasis which has eroded into bronchial vessels. treatment includes embolization if needed.
what is the cause of CF-related diabetes?
due to pancreatic insufficiency, hyperglycemia associated with weight loss and reduced lung function.
signs and sx of a CF pulmonary exacerbation?
cough, sputum, fever, decr FEV1, wt loss, dyspnea
a different concept of CF… multisystem disorder with what as the primary organs?
lung and pancreas
types of defects in the CFTR gene?
absence of synthesis, defective protein maturation, premature degradation, defective conductance or gating
