Transcription
Hey everyone, welcome to my channel, Medicos is Perfection Alice. In the previous video, we have discussed acute myelogenous leukemia. In this video, we will discuss a specific subtype of acute myelogenous leukemia called acute promyelocytic leukemia, or APL. It's very important for your exam because there is a lot of amazing stuff in this disease, and the question would like to ask you about them. So let's get started.
Don't forget acute promyelocytic leukemia has translocation 15;17. Acute, which means patients or younger cells are immature. Promyelocytic, which is not yet myelocytic; it's an older immature cell. Leukemia again, cancer of the blood, or more technically, cancer of the bone marrow. Okay, multipotent stem cells, hematopoietic, of course, we have the myeloid and the lymphoid. Myeloid will give us the red blood cells and all of these nice white blood cells. We have the myeloblast and the monoblast. See here, this is the promyelocyte. Okay, so this is the problem in acute promyelocytic leukemia, which is subtype M3 of acute myelogenous leukemia. And of course, they can have Auer rods. These are peroxidase-positive. Promyelocytic leukemia, M3 subtype; numerous Auer rods are present on the smear. Okay, which is very high yield. The translocation is 15;17, and we'll discuss this soon.
DIC is a common complication. This is a big deal, why? Because M3 subtype has a very good prognosis unless DIC occurs. So you have to be very careful when diagnosing and treating this patient because DIC is life-threatening. It can occur during the diagnosis or shortly after giving the patient chemotherapy. Please pay attention; DIC is a big deal. Has a very good prognosis, why? You can treat this with vitamin A. That's very nice. And here is a bonus: vitamin A will never cause bone marrow suppression. Yahoo! Because one of the main problems of giving the patient chemotherapy is bone marrow suppression, vitamin A is not gonna do this. How does vitamin A cure this problem? It induces maturation of these primitive promyelocytes into mature neutrophils. These neutrophils then undergo programmed cell death, or apoptosis; they will die. Rest in peace. Thank you so much.
But there is a problem with vitamin A: it can lead to something called differentiation syndrome, formerly known as retinoic acid syndrome, and we will discuss this syndrome in the next video, so stay tuned. Again, an amazing piece of information: arsenic can treat this leukemia. Are you kidding? Yes, this is a poison that can treat cancer. Wow, it's amazing. So you have a poison to treat cancer; you have a vitamin A to treat cancer. This is just astonishing stuff.
And here is my question for you: Do you know if an antibiotic can treat cancer? Yes, there is an antibiotic to treat cancer. I'm not talking about prevention of cancer; I'm talking about actual treatment of cancer. There's a specific type of cancer that can't be treated with an antibiotic. Let me know in the comments section; we will discuss this cancer later.
So for acute promyelocytic leukemia, you have numerous Auer rods, t(15;17) translocation; it's an M3 subtype. DIC is a complication; has a very good prognosis because we can give them vitamin A to mature these cells until they die. You can also give arsenic trioxide to treat this leukemia. The translocation happened: you have retinoic acid receptor alpha gene, or RAR alpha gene, on chromosome 15; you have another gene called promyelocytic leukemia gene, or PML, on chromosome 17. Translocation will happen, and these two genes will fuse, forming a chimeric protein, a fusion gene called PML-RAR alpha. Some people call it PML-RARA, okay, alpha or A; I don't care. Okay, this fusion gene will lead to arrest of differentiation of the promyelocytes and will lead to abnormal retinoic metabolism. That's why vitamin A is a hero, and it can treat this problem because vitamin A is also known as retinoic acid.
Some clinical uses of vitamin A: treatment of acne, of course, but it can lead to abortion. Okay, pay attention. Treatment of measles; it decreases the risk of blindness in measles. Acute promyelocytic leukemia, as you know, and it doesn't cause myelosuppression, which is pretty amazing. Treatment of hairy leukoplakia by Epstein-Barr virus. Treatment of retinitis pigmentosa.
Question for my great audience: 45-year-old female has extreme fatigue, mucosal bleeding. So we have anemia and maybe thrombocytopenia. Hematocrit is 27%; it's anemia. Platelets are 47,000; yes, it's thrombocytopenia. White blood cells 10,000; okay, this is normal, but 9% blasts on peripheral smear. This could be a leukemia. Let's do chromosomal analysis, and we get that t(15;17) translocation. Wow. First question: What's the diagnosis? And the answer is AML, M3 subtype. M5 leads to gingival hyperplasia; M5 doesn't have this amazing t(15;17) translocation, so this is the answer. Cool.
A common complication of t(15;17) translocation AML M3 is follicular lymphoma, PNH, DIC, or brain tumor. The answer: DIC. M3, three letters in DIC. What's the best initial therapy? Is it radiation, retinoic acid, herbal treatment, arsenic, or cyclophosphamide? Okay, two of them can be correct: retinoic acid, which is vitamin A, as well as arsenic. Okay, but the best initial, of course, I'll go with vitamin A, better than arsenic, no question. We are doing great. Thank you for watching. Please don't forget to subscribe. If you have any questions, ask me down in the comments; um, I will answer virtually every single question. And until next time, be safe, stay happy, and study hard.