Here we have one of the three
most lethal genetic diseases
in the caucasian
population in the US
Welcome to Cystic Fibrosis.
The other two being alpha-1 antitrypsin
deficiency and Down's Syndrome.
In cystic fibrosis remember, it
is inherited, autosomal recessive
mutation being in the cystic fibrosis
transmembrane regulatory protein or gene
which is a chloride channel.
Remember, the chromosome by chance
form biochemistry or genetics?
Good, chromosome 7.
In the specific was Phe508.
That at least you must know.
Now before I move on, we'll predict as
to what we can find in our patient,
just like we would do any case,
draw up a prediction, right?
So normally speaking, remind
me if it's in sweat.
That CFTR or chloride channel,
does it absorb or does it secrete?
It normally is going
to absorb, isn't it?
Let's talk about that one first.
So normally, if that
channel is to absorb
and now the chloride
channel is dysfunctional
Now you taste your infant... no I'm joking
don't do that, that's kinda creepy,
but you're definitely going
to do a sweat chloride test
So therefore, you'd expect there to be
an increase in chloride concentration
up to as much as or greater
than 60mEq per liter
And that takes care of the
sweat chloride test, correct?
Now remind me what may then
happen in your ducts.
and by ducts, referring to bronchioles
and maybe the pancreatic.
When your duct.. what you end up happening,
what's supposed to do in your duct
is the chloride channels are
supposed to secrete chloride.
What's secrete mean?
It's supposed to go
into the duct, right?
So now that the channel's no
longer working for chloride,
it remains behind in your cell.
Now, chloride is an anion.
It cannot live by itself ever.
It has to maintain a neutrality,
that is how our body's built
Obviously chloride is an anion,
its neutralizer would then
have to be what, please?
So now sodium hurriedly comes out
of the duct and comes into the cell
to then accompany
that lonely chloride.
And there you have
it, sodium comes in
but sodium doesn't also
come in by itself, does it?
along with it would
be water as well.
Now let us read this statement.
Suspect a newborn child with
unless sodium is leaving
But the sweat chloride
test would be high.
failure to thrive, of course.
or an adult with sinus disease, and
why would there be bronchiectasis?
Remember, you'd have bronchiectasis
in your lungs because the secretions
or the viscosity in your
duct is very very thick now
You may then resut in chronic bronchitis and
eventually may result in bronchiectasis.
In addition, the same type of issue or in a
male especially may result in infertility
Whereas in a female, it
might be subfertility
in which the lady would have
amenorrhea for example
Now that we took care of the lungs, let's
take a look at the pancreatic duct
Now please picture the
pancreatic duct for me please
Coming out of the head, and you're moving
towards your second part of duodenum,
to the ampulla of vater.
or now the duct becomes extremely thick
and viscous, things are gonna back up
and you're gonna end up developing
acute pancreatitis in perhaps a child
How would you know?
Well the child is now
grasping to the stomach
and maybe perhaps grasping to the back,
right, because of radiation to the back.
Now that you lose pancreatic
function in this child,
you're gonna result to
malabsorption, aren't you?
And by malabsorption, referring
to the fact that well,
I'm gonna have statorrhea
because I can't take in my fat.
If I can't take in my fat then I'll also lose
the ability to absorb fat-soluble vitamins
ADEK - (Vitamins) A, D, E, K
So what would be nice in terms of
management, what're you gonna do?
Why not take care of the lungs?
Take care of the lungs by giving, well
maybe beta-2 agonism to open them up
There's malabsorption so why
not give pancreatic enzymes
so that you can increase
the absorptive rate of fat
And so that you can take up the
middle chain fatty acids and such
So bronchiectasis is something
that you wanna treat
the pancreatic insufficiency is
something that you wanna treat
and with high fat diet
in replacement enzymes.
Remember without the pancreatic enzyme,
this would no longer work right?
This is really important for cystic fibrosis.
Next, well if you have such
inflammation taking place,
at some point in time, these
bronchioles start getting damaged.
So obstructive diseases in which
the bronchioles, the small airways
start undergoing obstruction,
it's what you're worried about.
Classic etiology, for example
if you have a child,
One of the most common causes of
viral pneumonia in children in fact
is RSV - Respiratory Syncytial Virus
and it will be in winter months
perhaps in closed quarters
and daycare centers
where all the children are running around
and in close encounter with one another.
Not usually to hear squeaks
on pulmo exam with wheezing,
so you might find
that quite often.
etiologies as well,
bronchiolitis obliterans, we
talked about that in conditions
where you have increased
The last time we looked at such a condition
was dealing with chronic bronchitis
in which there is increased deposition of
fibrosis resulting to loss of your bronchioles
Other times we will also take a look
at this is going to be in issues
such as what is called as
so these are going to be issues
in which there's going to be
a fibrotic peribronchiole
type of bronchiolitis
resulting in bronchiolitis
It could also be seen with
rheumatoid artritis as well