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Additional Malignant Diseases of Blood – Diseases of the Blood System

by Paul Moss, PhD
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    00:00 There are other types of diseases of the blood, malignant disorders that dont fit so neatly into this leukaemia or lymphoma classification. Let me just briefly introduce those, although they are very complex diseases in their own right.

    00:18 Myeloproliferative diseases. it's a long word, What does it mean? Well it makes sense to think about it.

    00:25 Myelo means bone marrow, proliferative - overactive.

    00:31 These are disorders in which the stem cells in the bone marrow are growing too rapidly, too much proliferation and producing cells, which then get pumped into the blood.

    00:42 You might have too many red cells, might have too many white cells or too many platelets and we're now understanding that they often have very common genetic defects that put them together.

    00:57 In the same token, myelodysplastic syndromes. Again just think about that word, myelo-bone marrow, dysplasia-dysfunctional. Here the bone marrow is still quite active.

    01:11 Indeed, if you take a bone marrow biopsy, the bone marrow can be very proliferative, but in fact within the blood, the blood count is reduced. These cells are dysfunctional.

    01:23 These can be regarded as perhaps an earlier form of an acute myeloleukaemia.

    01:30 We know that the stem cells have become very damaged, they have acquired mutations.

    01:34 These are often seen in older individuals and it can be a very challenging disorder to treat.

    01:41 Finally at the bottom, a very important disease, myeloma. This is a malignant disorder of plasma cells in which the tumour produces antibodies at quite high levels within the blood system.

    01:55 It can lead to a range of clinical problems.

    01:59 Let's move now to disorders of platelets. You'll see on the right there, a blood film, dominated of course by red cells. There is a purple, large white cell at the top and you will see the small purple platelets at the bottom.

    02:15 Now deficiency of platelets is called thrombocytopenia, thrombocyte - platelet, penia - reduction.

    02:24 and this leads to bruising and bleeding. We will bruise from time to time but what we're really interested in here in people who have severe or spontaneous bruising or bleeding.

    02:37 There are many causes of reduction in the platelet count. It can include antibodies, for some reason we are quite prone to making antibodies against our own platelets and leading to their increased destruction, sometimes drugs can do that as well. On the other hand if we have too many platelets, that is called thrombocytosis. And you might think well, too few platelets leads to bleeding, too many might lead to blood clots and you're absolutely right, that is the case. Although quite paradoxically, when your platelet count gets very high, you can actually be prone to bleeding as well.

    03:16 Sometimes it's just not about the number of platelets, it depends on whether they are working or not, the function of the platelet, and that can be impaired in a number of conditions.

    03:30 One very common one is the use of aspirin. Millions of people around the world, taking aspirin every day.

    03:36 The reason? They want to reduce the function of their platelet to stopping cells developing disorders perhaps such as atherosclerosis and heart disease. Shows how important the clotting system is in many of the common diseases that we see these days.

    03:55 Let us now move on to the other component, which is very necessary for making your blood clot - coagulation factors, the proteins in the blood that are involved in forming a blood clot.

    04:08 A deficiency in the protein is the cause the blood to clot can arise either due to an inherited disorder or occur later in life - what we call an acquired disorder. The most important inherited one, which I am sure you have heard of is haemophilia. Haemophilia A is where the patient B(oy) has a deficiency of factor VIII. Haemophilia B less common, deficiency of factor IX, and that can lead to a range of clinical problems starting early in life with early bruising, bleeding and indeed problems with bleeding into muscles and joints. There are many many acquired problems that we can develop in our lifetime, which lead to coagulation disorders. Sometimes severe infections can overwhelm us and lead to clotting problems or sometimes perhaps following complications in childbirth leading to a disorder called disseminated intravascular coagulation. That's quite a severe problem, in which patients have so much coagulation going on that they use up all the coagulation factors and start to bleed.

    05:28 You are probably wondering what that photograph is on the right.

    05:32 That's a patient who actually had quite an unusual condition of ACQUIRED HEMOPHILIA, a rare condition in which they developed antibodies to factor VIII and essentially developed a clinical picture of haemophilia and you can see the very large of bruise around the neck.

    05:51 Now, the opposite to bleeding problems is too much clotting - disorders of thrombosis, and these disorders are now probably more important than bleeding disorders.

    06:09 Many people are born with a slight tendency for their blood to clot more easily.

    06:13 We call it THROMBOPHILIA. It probably makes sense why genes have developed slight differences or allelic change to make our blood clot more easily, give us more protection when we're injured perhaps.

    06:30 But the risk is also increased in a number of settings and you will notice that these are very common in patients in a hospital - the people who are having bed rest, who've had recent surgery or irregular heartbeats, heart arrhythmias.

    06:46 And so now, the use of drugs to stop blood clotting, so called antithrombotic drugs, is one of the most important areas of medicine.

    06:57 So, in summary, a wide range of different clinical conditions can arise from disorders of the blood.

    07:06 If you look at red cells, we'll see that anaemia is extremely common within the world and has a range of different causes. Within white cells, probably the most serious conditions are leukaemia and lymphoma. Whereas platelets and coagulation disorders can either lead to excessive bleeding or an increased tendency for the blood to clot.

    07:31 And I hope I have convinced you in this lecture that the treatments for these disorders are very diverse, but they are improving all the time and there is now a great deal we can offer to the patient with a haematological disorder.

    07:46 I hope you have enjoyed this lecture.


    About the Lecture

    The lecture Additional Malignant Diseases of Blood – Diseases of the Blood System by Paul Moss, PhD is from the course Hematology: Basics.


    Included Quiz Questions

    1. Infection and thrombosis
    2. Infection and fatigue
    3. Lymphadenopathy and bleeding
    4. Infection and shortness of breath
    5. Lymphadenopathy and thrombosis

    Author of lecture Additional Malignant Diseases of Blood – Diseases of the Blood System

     Paul Moss, PhD

    Paul Moss, PhD


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