we’ll divide this into megaloblastic
For those of you that were unclear or
unsure about the differences between
megaloblastic and non-megaloblastic
both being under macrocytic,
well, we’ll be clarifying
that in this lecture series.
Macrocytic anemias are
most commonly caused by,
well, some of the megaloblastic we’ll
take a look at are B12 and folate.
These are the age old vitamins
that you will be talking about
and have been discussing in your
medical education for years now.
So, we should be able to go
through this rather quickly.
So, I will just reinforce those
little biochemical facts
that become really
important for us.
We’ll take a look at B12
and folate deficiency.
Both of these are
if it’s B12, we will take a look at
this in number of DNA steps synthesis
as is folate.
Now, what does that even mean and how can
you then associate this with megaloblastic?
So you need B12 and folate
for proper DNA synthesis,
both purines and pyrimidines, right?
Especially that step that we'll
be dealing with quite a bit.
We are trying to
turn dUMP into dTMP.
And if you don’t B12 or folate,
then you can’t produce proper DNA.
Where do you form RBCs?
Is it only RBCs that you
produce in bone marrow?
That’s a stupid question, isn't it?
So you’re going to form many, many,
many cells, hematopoietic stem cells.
That’s what you have,
And you give rise to myeloid.
And by myeloid, we mean that referring
to our megakaryocytes and platelets,
referring to erythropoiesis and RBCs,
and our granulocytes referring to our
neutrophils, eosinophils and basophils.
Okay. What will happen if you
didn’t have proper DNA synthesis
and the bone marrow
has been affected?
Then you don't have proper
maturation of your cells, do you?
What’s this called when you don’t
have proper formation of platelets,
proper formation of RBCs nor your
proper formation of your granulocytes?
It’s called pancytopenia.
Fascinating, isn’t it?
Now, if you have pancytopenia and you’re
producing immature type of cells,
especially RBCs, that’s what
we are doing here, macrocytic,
then you’re going
to form this blasts.
What does a blast mean to you?
It means it is an immature type of
cell that’s inside my bone marrow.
Last time we had this discussion,
ladies and gentlemen,
was when we’re dealing with sideroblastic
anemia and microcytic anemia.
And we were talking about
the porphyria pathway
Do you remember that?
So here macrocytic, what are you
looking at first and foremost?
Interpretation of this, I’ll walk you
through the history, not to worry.
But labs, you have an MCV greater than 100.
An MCV of greater than 100,
that’s where we are right now.
In addition, you’ll end up forming or
having pancytopenia and megaloblast.