Aplastic Anemia – Hematopoietic Malignancies and Aplastic Anemia

00:02 Finally, let's finish with another important hematological disease, although not a malignant disorder.

00:10 This is aplastic anemia.

00:13 And this is a rare condition.

00:15 But it's characterized by low blood counts due to the fact that there's a reduction in cellularity of the bone marrow.

00:24 Just look at that slide on the right, that is a bone marrow biopsy, a terrifying biopsy of the bone marrow.

00:33 And you can see there are too many holes in that, too many fat cells, not enough hemopoiesis.

00:43 Now, why would this arise? Well, in adults, a probably arises we think, because the immune system is somehow damaging the stem cells within the bone marrow and reducing their numbers.

00:58 Just to get our terms correct, bone marrow may be actually hypoplastic that means a reduced cellularity or completely aplastic empty.

01:12 Out of interest, that slide on the right I would call hypoplastic and you can see there is still some hematopoiesis there, but it's reduced from what it normally would be.

01:23 Now then, let's think about why aplastic anemia may arise.

01:30 Now, occasionally, we see this in children.

01:34 And this usually arises because of inherited abnormalities that they've got due to damage genes from their mother, or father.

01:42 Fanconi Anemia, is one of the most common of these collectively rare disorders.

01:49 And you'll see, on the top right, some of the skeletal abnormalities in the digits that you can see in Fanconi Anemia.

01:58 And below that some of the otter skin pigmentation that you may also see here.

02:05 But in adults, aplastic anemia usually arises out of the blue, as we call idiopathic. No obvious reason why.

02:15 Although it may occasionally follow episodes of hepatitis or an unusual reaction to drug therapy.

02:24 We make the diagnosis by doing that all important bone marrow trephine, which shows the empty bone marrow lacking in stem cells.

02:36 Then what can we do about it? Well, treatment has two major components.

02:43 One is supportive therapy.

02:45 We keep the patient alive despite the fact that their bone marrow is not working properly.

02:50 We can transfuse red cells. We can transfuse platelets.

02:56 Neutrophils are more challenging, and we don't usually do that and we try to control infection with antibiotics and antifungal agents.

03:07 A specific treatment aims to reverse the process of aplasia and start the bone marrow being produced again.

03:17 And here we tend to use immune suppression with a drug is called anti-lymphocyte globulin.

03:25 This is an unusual product in which human lymphocytes are injected into an animal, perhaps a horse, or rabbit even.

03:34 And those animals will make antibodies against the human lymphocytes, which we can purify and give to patients.

03:41 And you can imagine that that reduces the lymphocytes in the patient, and it's quite an immune suppressive therapy.

03:50 It's been proven to be pretty highly effective in patients with aplastic anemia.

03:56 We often combine this with a drug called cyclosporine.

04:00 That's an immune suppressant drug as well, and is often used in people who have had a kidney transplant to reduce organ rejection.

04:10 In patients with moderate disease, that would be the approach you would take if they had a very severe aplastic anemia with very low blood counts.

04:19 You may also think of a bone marrow transplant an allogeneic bone marrow transplant from another person and that can be highly effective in people with severe disease.

04:34 So in summary.

04:36 What we've seen in this lecture is that a wide variety of disorders may develop within the hemopoietic system.

04:43 Myelodysplasia results from a wide range of mutations that damage the ability of hematopoietic stem cells to produce functional and effective blood cells.

04:55 Myeloproliferative diseases have a well defined genetic basis and lead to over active bone marrow, often with clinical splenomegaly.

05:05 And myeloma is a malignant disease of plasma cells leads to bone damage, and paraprotein which itself can cause a range of clinical problems.

05:15 Finally, aplastic anemia is a rare but serious condition that may result from stem-cell failure perhaps as a result of an inherited abnormality or from autoimmune damage.

05:30 Thanks for watching this lecture on hemopoietic malignancy.