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Myelodysplastic syndrome
Myelodysplastic syndrome is sometimes referred to as “pre-leukemia” or a condition that occurs before leukemia (although most patients will never develop leukemia). In myelodysplastic syndrome, the gene mutation preventing the maturation of the blast cell is present, however the second gene mutation leading to uncontrolled cell replication is absent. Learn how health professionals look at blood test results and bone marrow aspirates to diagnosis this disease. Created by Nauroz Syed.
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- Great lecture. It makes me wonder, is there such a condition as Lymphodysplastic Syndrome?(14 votes)
- Dysplasia simply means cells, tissues, or anatomical structures growing or developing abnormally. So if there is myelodysplasia, meaning dysplasia of myeloid (blood-related) cells, then there can certainly be dysplasia of lymphoid cells, a.k.a. lymphodysplastic pathologies.(6 votes)
- This is very good and informational but how do you prevent leukemia(3 votes)
- There is no way to prevent leukemia, but there is treatment if you find out you have it early enough.(3 votes)
- When she said in the end that patients will die long before their cells will have a chance to acquire a second mutation, did she mean that they will die of MDS or of natural causes?(2 votes)
- Unfortunately, MDS has a mean survival rate of less than a year, up to 30 or so months, depending on type.(1 vote)
- What causes the gene mutation in the blast cells? Is it genetic or is it acquired in another way?(1 vote)
- It depends. Gene mutations can be caused by either chromosome translocation or radiation amongst other reasons. Hope this helped! :D(2 votes)
- Is the treatment for MDS different from that for leukemia?(1 vote)
- If MDS is immature, and doesn't have any symptoms, how is it deadly, or did I miss the symptoms?(1 vote)
- it does has symptoms, the symptoms mirror the symptoms or leukemia because of the immature blast cells taking up space of the red blood cells (less oxygen delivered to the body) white blood cells (body more exposed to infection, platelets you bleed out more. the only difference is that the immature blast cells aren't dividing rapidly. Like seen in leukemia.(1 vote)
- Leukemia is a very bad disease but isn't ebola or parasites worse?(1 vote)
- Can there be 2 mutations tat do not lead to Leukemia or allowing the cell to mature but rapidly divide?(1 vote)
- Honestly, after 5 months of no answers from ANYONE, i don't think so. #5MonthsAgoByBryton(1 vote)
- This sounds like a leg injury, is it?(1 vote)
- What's the survival rate of MDS ,is leukemia lower ? Which one makes you die faster?How's the treatment different from leukemia since the only difference was the number of mutant genes?does bone marrow create blasts and normal cells at the same time?(1 vote)
- At the moment, there is no treatment for MDS and the survival rate, mentioned by Physio Crisis, is up to 30 months. This makes MDS more deadly than luekemia. also, bone marrow doesn't have only one stem cell inside. The stem cells are given instructions on what type of cell to change into, e.g. a B-cell lymphocyte, and starts off as a blast cell, eventually growing into a mature cell.(1 vote)
Video transcript
Myelodysplastic syndrome
is usually something that's tucked away into
the corners of a textbook, in the section where they
talk about leukemias, and it's usually described
as being a pre-leukemia. So, a precursor condition to
the development of leukemia. and that's not always
necessarily the case. That's not entirely true. So, what we're going to do
is, we're going to dedicate this entire video to talking about myelodysplastic syndrome, which is usually abbreviated MDS, and we're
going to try to clear up whether MDS really is or is
not a pre-leukemia, okay? So, let's start off by letting
the name of the disease tell us a little bit more about it. So, myelo-, myelo-, myelo-
tells us that we're talking about myeloid cells, right? So, we're talking about
red blood cells, platelets, neutrophils, basophils, and eosinophils, and dysplastic, I'll
use a different color, dysplastic comes from the Greek
word, I'll write that here, comes from the Greek word,
dysplasia, dysplasia, which means abnormal, abnormal. So, we're talking about
abnormal myeloid cells, okay? And that requires some
further elaboration. How are they abnormal? Well, let's look here again at the development of a normal
blood cell, all right? We've seen this before,
a hematopoietic stem cell developing into a mature
specialized blood cell. Well, in the case of
myelodysplastic syndrome, your immature blast cell, your immature myeloid blast
cell, is abnormal-looking, it's very strange-looking, and
why does it look so strange? Well, it's because it has a DNA mutation. So, it has a mutation in
its instruction manual, in the instruction manual of
the cell, and that causes it not only to look abnormal but
also to function abnormally, and by that I mean that this
cell doesn't mature the way that it should, so it can't
move on to the next stage. It's kind of stuck in
this immature blast stage, and we've seen this before, right? This is actually the first
step in the development of leukemia; however,
something that we notably don't see over here is the second step that was required in
leukemia, and that was a second gene mutation that
would then cause the cell to start dividing rapidly
and out of control. We don't see that in MDS, and that means that this isn't a cancer
of immature blast cells. Instead, this is a
condition in which you have immature blast cells that
have an abnormal appearance, that can't mature and develop like normal blood cells should, okay? So, the hematopoietic
stem cell, unfortunately, continues to make more of
these abnormal blood cells that don't mature, and
even if the hematopoietic stem cell is able to
make a normal blast cell that is then able to
mature all the way down to the mature specialized stage,
there's something wrong with these cells, something that we don't quite understand fully yet, in which these mature specialized cells die off quicker, die off quicker than
normal blood cells should, and you can imagine that
because of these two situations, because of mature cells dying off quicker and immature cells not
being able to develop the way that they should,
in myelodysplastic syndrome our primary problem is
that the bone marrow isn't able to put out as many
myeloid cells as it should, so there's a decrease in the number of your myeloid cells,
your myeloid cells, okay? And that's really where the symptoms of myelodysplastic syndrome come from, and we talked about that
a little bit before, the symptoms that you
get when you don't have enough red blood cells or enough platelets or enough white blood cells. So, these patients, unfortunately, require constant transfusions. They require constant supplementations with the types of cells
that they're missing, in order for their bodies
to continue functioning the way that they should. Now, if the primary problem
in myelodysplastic syndrome is that you don't have
as many myeloid cells as you should, you can
imagine that a patient who has myelodysplastic syndrome presents very similarly to a
patient who has leukemia, and that's very true. They present very similarly, and so, if you had a patient
presenting with these symptoms, you would go through and order the tests that we talked about. You'd order some blood
tests, and then you'd proceed with getting a bone marrow aspiration. So, you'd take a look
inside a person's bone. I wonder if I have enough room
to draw this, just barely. That's your central cavity
that contains the bone marrow, and we said a bone marrow
aspiration involves sticking a needle into that cavity. All right, here's my
needle, it's a big needle, and drawing out some fluid and looking at the bone marrow underneath the microscope. And now, we said that
in normal bone marrow, normal healthy bone marrow,
only two to three percent of the cells will be blast. I'm going to put that in
a capital B, blast, right, in normal cells, in a normal bone marrow, normal bone marrow. Now, in leukemia we said
that we would have greater, because we have a cancer of these immature blast cells, in
which they're dividing rapidly and out of control. We have tons and tons of
these immature blast cells. So, to put a number on it,
we said that we would see greater than 20 percent blast cells. I made that kind of look like a one. Okay, greater than 20 percent
blast cells in leukemia, in leukemia. Now, in myelodysplastic
syndrome, yes, we would see an increase in the number
of immature blast cells, compared to the number of mature cells, simply because these
cells aren't maturing, aren't turning into mature
cells, aren't turning into these specialized mature cells, right? So, we'd expect to see a
greater number of these immature cells, compared
to the mature cells. However, because we don't
have a cancer of these cells, these cells aren't dividing
rapidly and out of control, we wouldn't expect to see greater than 20 percent blasts, as we do in leukemia. Instead, we see less than,
less than 20 percent blasts but greater than two to three percent. So, greater than what's normally expected, but less than what's seen in leukemia, and that's what we see in
myelodysplastic syndrome. Now, one last point that I'd like to make about this disease is that
we said that the cause of myelodysplastic
syndrome, this gene mutation that prevents the cell from maturing, was the first step that was required for the development of leukemia, right? So, we had step one already occurring, and you can imagine that
if then in this cell you had another mutation
develop, that caused the cell to start dividing uncontrollably, that would then lead to a leukemia. It would lead to a
myeloid leukemia, right? And since these are very immature cells, it could lead to an
acute myeloid leukemia, and that's why people often refer to myelodysplastic syndrome
as being a pre-leukemia, because you already have
one mutation required for the development of
leukemia, all you need is another one, and if
you were then to acquire the second mutation, your
myelodysplastic syndrome would transform into an
acute myeloid leukemia. Now, the only thing is
that this doesn't happen nearly as often as we think it does. It's actually quite uncommon. Most people with myelodysplastic syndrome, most patients will die before
their abnormal blast cells ever have a chance to
acquire that second mutation and transform into acute myeloid leukemia.