00:01
Let’s take a look at
hereditary spherocytosis.
00:05
HS is what I’m going to refer to this as.
00:08
Hereditary spherocytosis
is a membrane issue
and the name pretty much tells you
everything that you need to know.
00:15
Where am I in terms
of your category?
You are normocytic anemia,
you’re looking at MCV
between 80 to 100.
00:24
So what then happens when
there’s enough membrane loss?
Now, in your mind, conceptually
work with me here.
00:31
And a normal RBC is biconcave,
whatever that means.
00:36
And point being is it has
central pallor, right?
And so therefore, if you start losing
parts of the membrane, what then happens?
The membrane is then going to become
more and more of a spherocyte.
00:49
It loses its "biconcave shape."
What then happens to
the central pallor?
It’s no longer present.
00:57
So it’s highly concentrated.
01:01
Now you give me another test
in which it then tells you
that you have a highly
concentrated RBC,
where the RBCs homogenously
reddened or are hyperchromic.
01:14
MCHC.
01:17
Clear?
So we have two major RBC index
that we’ll take a look at.
01:22
Number one, it’s a fact that, well, your
normocytic is where we are, 80 to 100.
01:26
Number two, in terms of reticulocytosis,
you expect your reticulocyte
production index
to be increased or
decreased here, please?
Increased.
01:36
And we find MCHC because of increased
hemoglobin concentration to be high as well.
01:42
So what is this important membrane
component that’s missing in HS?
Spectrin, spectrin, spectrin.
01:49
You also have ankyrin as well, but spectrin
is a major, major membrane component.
01:54
Now, those of you that are
interested in going into hematology,
you’ll be dealing with and
spending a lot of time
with that RBC membrane
for various reasons.
02:04
There are all of these antigens.
02:06
You all know about D antigen, right?
But you have all of these
antigens and membrane components
that you’ll have to know about.
02:13
At this point, I would know
that spectrin is becoming lost,
resulting in an RBC that
looks like a sphere,
spherocyte.
02:23
Next, may I ask you a question?
If more that you have concentration
increasing within the RBC,
then tell me about its osmotic
pressure inside the RBC,
increased or decreased?
Keep that in mind.
02:38
Let’s move on.