Transcription
Hey medicos, perfection Alice. Once again, we're talking about Leukemia and Lymphoma. It's an introduction. In the previous video, we have discussed white blood cells. Today, let's get more specific and discuss the lymphocytes.
The lymphocytes are non-granulocytes, which means they do not have granules in their cytoplasm. The nucleus is huge, and there is very little cytoplasm left. There is a little rim of the cytoplasm around the nucleus. Why did we call them lymphocytes? "Sites" means cell. "Lymphoma" means lymph nodes or lymphatic system. But, of course, as you know, we can find them in the blood and in the lymphatic system. Lymphocytes are members of the white blood cells, if you don't know that already, there is no hope for you. Lymphocytes are non-granular, of a lymphoid origin. There are three types of them: the natural killer cells. They are the nonspecific, straight fighters. Okay, they are used in the innate as well as the adaptive immunity. Then there's the T cell—very specific cell-mediated adaptive immunity—and we have the B cells or B lymphocytes—humoral immunity. Humoral means body fluids, because these B cells will get converted into plasma cells, and they will produce a lot of antibodies into the body fluids. That's why it's known as humoral immunity—again, an adaptive immunity. The only one of these that participate in the innate immunity are the streetfighters, natural killer cells.
Now, please don't confuse humoral with an "O" with humoral with an "E". This is related to the bone called humerus, and we are not talking about anatomy for heavens sake. And where can you find your lymphocytes? So they start in the bone marrow—it's called hematopoiesis—then they mature in other tissues. The T-cells mature in the thymus; by the way, that's why we called them T-cells. Okay, and the B cells mature in the bursa. Now, humans do not have a bursa; we have a bursa equivalent called gut-associated lymphoid tissue—part of the mucosa-associated lymphoid tissue—in your Peyer's patches and other places. That's fine. Now, after maturation, then goes the circulation, and of course, they circulate in the bloodstream as well as in the lymphatic system, and they pass through lymph nodes.
Leukemia, lymphoma. Now here comes a question: Where can we find lymphoma? We know that we can find leukemia in the bone marrow as well as in the bloodstream, but what about lymphoma? Okay, all of these—thymus—can get lymphoma. Yes, it's rare, but it can happen. Your MALT tissue can get lymphoma, called malt lymphoma or maltoma. Fine. Your lymph nodes, of course, they can get lymphoma, and they're called lymphoma. So, leukemia in your bone marrow and in the bloodstream; lymphoma in the lymph nodes, thymus, and mucosa-associated lymphoid tissue.
Differentiate between T lymphocytes and B lymphocytes in the peripheral smear under the microscope? No, tsuita—possible? Ah, it's impossible. That's why we need flow cytometry. Okay, flow cytometry detects cluster of differentiation, CD. What are these? So how does the police know if you are John, Sarah, I've met, or anybody else? By showing your ID. How do we know that this cell is T lymphocyte, B lymphocyte, or natural killer cells? By showing their CD, their cluster of differentiation. Natural killer cells are CD16 positive and CD56. T cells can be T helper—CD3 and CD4—and the T cytotoxic—CD3 and CD8. Collectively, the T cells can be CD3 positive, CD4 positive, and/or CD8 positive. B-cells: MHC2, CD19, and CD20. If you know all of these, you know hematology and oncology pretty well. Let's say that we find a cell that is CD20 positive. You have a B-cell leukemia or lymphoma—boom. What if it's CD3 positive, CD4 positive? You have a T helper cell leukemia or lymphoma. Okay, so easy. Let's go to the next level. Okay, I'm telling you, I found a CD3 positive, CD8 positive cell in the bone marrow. You have T-cell leukemia. What if it was in the lymph node? You have T-cell lymphoma. Cool. I mean, it's cool to diagnose the disease, but it's not cool if you have T-cell lymphoma.
I'm so sorry for watching. I'll see you in the next video that I will call "Distinctions in Oncology." Wow. Until next time, be safe, stay happy, and study hard.