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Current time:0:00Total duration:8:18

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 Milo Milo Milo 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 use a different colour dysplastic comes from the Greek word right 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 of normal well let's look here again at the development of a normal blood cell right we've seen this before I'm at aquatic stem cell developing into a mature specialized blood cell well in the case of Milo dysplastic syndrome you're immature blast cells are immature myeloid blast cell is 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 as a mutation in its instruction manual and the instruction manual of the cell and 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 metabolic stem cell unfortunately continues to make more of these abnormal blood cells that don't mature and even if the amount of what accept cell is able to make a normal blood cell that is then able to mature all the way down to the mature specialized stage there's something wrong would be cells something that we don't quite understand fully yet in which these mature specialized cells die off quicker die off quicker then 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 we're myeloid cells okay and and that's really where the symptoms of my low dysplastic 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 platelet er enough white blood cells so these patients unfortunately require constant transfusions they require constant supplementation with the types of cells that they're missing in order for their bodies to continue functioning the way that they should now it's a primary problem in my lower dysplastic syndrome is that you don't have as many myeloid cells as you should you can imagine that a patient who has myelodysplastic syndrome present very similarly to a patient who has yeah 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 test that we talked about you'd you would order some blood tests and then you'd proceed with getting a bone marrow aspiration so you you take a look inside a person's bone I don't wonder if I have enough room to draw this ah just barely that's your central cavity that contains the bone marrow and we set a bone marrow aspiration involves sticking a needle into that cavity right here's my needle big needle and drawing out some fluid and then looking at the looking at the bone marrow underneath the microscope now we said that in normal bone marrow normal healthy bone marrow only two to three percent of the cells will be blessed I'm going to say what 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 blood cells so to put a number on it we said that we would see greater than 20% blast cells that kind of looks like a 1 ok greater than 20% 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 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% blasts as we do in leukemia instead we see less than less than 20% blasts but greater than 2 to 3% so greater than what's normally expect 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 the the cause of Milo dysplastic 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 prevented the cell from that that led the cell to start 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 milo dysplastic 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 you're Milo dysplastic 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 will die before their abnormal blast cells ever have a chance to acquire that second mutation and transform into acute myeloid leukemia