Aplastic anemia

• What is aplastic anemia?

• pancytopenia with hypocellularity (aplasia) of the bone marrow.

• There are no leukaemic, cancerous or other abnormal cells in the peripheral blood or bone marrow.

• What is the underlying pathophysiology?

• Due to a reduction in the number of pluripotential stem cells together with a fault in those remaining or

• An immune reaction against them so that they are unable to repopulate the bone marrow.

• What are the causes?

• What is the underlying immune mechanism that causes bone marrow failure?

• Activated cytotoxic T cells in blood and bone marrow are responsible for the bone marrow failure.

• What are the drugs that cause marrow aplasia?

Cytotoxic drugs:• Busulfan• Doxorubicin

Non-cytotoxic drugs:• chloramphenicol• gold• carbimazole• chlorpromazine• phenytoin• ribovirin• tolbutamide• NSAIDs.

• What is Fanconi’s anemia?

• Fanconi’s anaemia is inherited as an autosomal recessive

• Associated with skeletal, renal and central nervous system abnormalities.

• It usually presents between the ages of 5 and 10 years.

• What are the clinical features of aplastic anemia?

• Lack of Hb = Anemia • Lack of platelet = Bleeding • Lack of WCC = Infection

• What is the typical feature on marrow?

• Pancytopenia• The virtual absence of reticulocytes• A hypocellular or aplastic bone marrow with

increased fat spaces

• What are the causes for pancytopenia?

• What are the bad prognostic signs?

Presence of two of the following three features:• neutrophil count of < 0.5 × 109/L• platelet count of < 20 × 109/L• reticulocyte count of < 40 × 109/L.

• What is the treatment?

• Supportive care- RBC/platelet transfusion prn• Treat infection early- Broad spectrum IV abx.• Bone marrow transplant (Rx of Choice)-only if

age <40.

• What is the outcome of bone marrow transplant?

• Results are poor for unrelated donors.

• For those with HLA-identical sibling donor, 75–90% chance of long-term survival and restoring the blood count to normal.

• Why is bone marrow transplant not eligible for patients age >40?

• High risk of graft-versus-host disease as a complication of bone marrow transplantation.

• Use Immunosuppressive therapy, antilymphocyte globulin (ALG) and ciclosporin in combination which gives a response rate of 60–80%.

• Why is giving growth factors ineffective in aplastic anemia?

• Levels of haemopoietic growth factors are normal or increased in most patients with aplastic anaemia

• Therefore they are ineffective as primary treatment.

• What is the role of steroids?

• Little activity in severe aplastic anaemia but are used for serum sickness due to ALG.

• They are also used to treat children with congenital pure red cell aplasia (Diamond–Blackfan syndrome).

• What is the common condition associated with adult red cell aplasia?

• Adult pure red cell aplasia is associated with a thymoma in 30% of cases and thymectomy may induce a remission.