- [Voiceover] The gold standard for diagnosing
Cystic Fibrosis is called the Sweat Test.
Now it's not where you have to exercise
a lot and sweat a lot, but the sweat is used
to analyze how much chloride is in there.
So the point of this whole test is how much chloride.
And an abnormally high chloride points to Cystic Fibrosis.
A lot of times this test is done in babies
and for full-term babies actually age two to four weeks
you can already have an accurate test.
And the reason why they might get one
or the doctor might order one is for example,
if they have a genetic reason to maybe have CF,
their parents carry the gene or
they could have an abnormal newborn screen.
Now every baby who is born in the
hospital gets a newborn screen.
They test for metabolic factors, things that can
potentially point to CF and if they have something
abnormal there they usually get the Sweat Test.
So it's a test that we do if we suspect CF.
And the way it's done is actually very simple.
The baby or the person doesn't really even have to move.
So first we apply a solution to the skin,
wherever the area we're testing,
which encourages it to make sweat.
And then we take two electrodes, one positive, one negative,
put it on the skin, turn on the current
and this current stimulates the sweat glands.
So if this is the skin, back here is the sweat gland.
So after it is stimulated to make sweat we then collect it,
send it to the lab and see how much chloride there is.
That is the Sweat Test.
Of course you can always go for genetic testing,
right to the source of the gene.
We already know what the gene is, and remember it's CFTCR.
A thing to remember about this is that even though
this is the gene that causes the disease
there are many variations between people who have CF
who have different variants of it,
so it's not always as cut and dry,
but for the most part analyzing this gene,
seeing if it's normal can diagnose the CF.
The Sweat Test and genetic testing are
more or less answering a yes or no question,
but to ask that question at the appropriate time
there are diagnostic clues that we should look for
in people who might not know that they have CF.
So for people who work with kids when they're
even just babies it's important to watch out for
people who have failure to thrive,
which just means they're not
gaining weight and growing as they should.
And the first thing you do is make sure
the parents are feeding them correctly.
But after that you start looking for
what we call organic causes,
or what's within the baby's metabolism
that causes this, and CF is a big one.
So failure to thrive, maybe it's good to do a Sweat Test.
Or people who are having a lot of frequent, long infections,
especially with bacteria or organisms that are not
usually found in normal people.
For example psuedomonas, this is something that thrives
in the environment of the thick mucus that
Cystic Fibrosis patients have in their lungs.
So this is a type of pneumonia that's seen in a lot
of CF patients, but not necessarily in people
who don't have it, so this again should
tip you off to look for the CF.
Of course there's malnourishment, malnutrition I should say
because they can eat all the food in the world,
but if CF stops their pancreas from helping them
digest it then they will have malnutrition.
You can get things like a chest x-ray if you want
to see the overinflated lungs.
You can get abdominal x-ray in babies
because CF can affect the intestines
and sometimes it is visible on the film.
But one thing, actually speaking of babies,
that I want to point out is to watch out for
babies who have delayed meconium.
Not to gross you out, but meconium is the brown
sludge that comes out of a baby when they're first born.
It's kind of like their first poop, but it's not real poop
because they haven't eaten yet, but if the sludge
doesn't come out there are several reasons that could be
and CF is one of the major reasons.
So working with newborns if they don't pass
meconium within the first few hours like normal
babies do, it's worth it to look into that further
and see if they possibly could have Cystic Fibrosis.
Diagnosing CF is not really a huge mystery
because we know the gene, we know the Sweat Test
has a good accuracy, so the key in Cystic Fibrosis
diagnosis is to watch out for these clues
and think of CF when you see them.