Aplastic anemias &Secondary Anemias Flashcards
What is Aplastic Anemia
Defined as pancytopenia resulting from aplasia of the bone marrow
Describe the marrow in Aplastic Anemia
Hypo cellular Marrow in which normal haemopoietic marrow replaced by fat cells
What is the pathophysiology of Aplastic Anemia
A reduction in the number of hematopoietic pluripotential stem cells
What is pancytopenia
Describes a reduction in the blood count of all major cell lines- red cells, white cells and platelets
Aplastic Anemia is classified into which two types
Primary (congenital or acquired)
Secondary
What are the two types of primary causes of Aplastic Anemia
Congenital
Idiopathic acquired
What are the two types of Congenital Aplastic Anemia
Fanconi and Non Fanconi Types
What are the four main secondary causes of Aplastic Anemia
Ionizing radiation
Chemicals
Drugs
Viruses
List examples of exposure to Ionizing Radiation that may cause Aplastic Anemia
Radiotherapy
Radioactive isotopes
Nuclear power stations
Exposure to which drugs/ chemicals may lead to Aplastic Anemia
Cytotoxic drugs:
Benzene
Organophosphates
DDT and other pesticides
True or False
Exposure to Cytotoxic drugs that causes Aplastic Anemia is usually reversible
True
Which drugs occasionally cause bone marrow aplasia
Chloramphenicol
NSAID’s
Insectisdes
Gold
List four drugs that regulary cause marrow depression
Busulfan
Cyclophosphamide
Anthracyclines
Nitrosoureas
List four viruses that cause Aplastic Anemia
Hepatitis non A non B
Parvovirus B19
EBV (rare)
HIV
Hepatitis non A non B can cause Aplastic Anemia about how many weeks after infection?
6-12 weeks
Parvovirus leads to transient aplasia of which blood line
Red cell
What fraction of Aplastic Anemia cases are no underlying cause found
2/3
What is the pattern of inheritance of Fanconi caused Aplastic Anemia
Autosomal recessive
When is the onset of Aplastic Anemia
Any age
When is the peak incidence for aplastic anemia
30 yrs
Which gender is slightly more susceptible to Aplastic Anemia
Male
List some clinical features of Aplastic Anemia
Non specific, the symptoms are due to the pancytopenia effect
- infections
- bruising/ bleeding gums, epistaxis(nose bleed), menorrhagia
True or false
Lymph nodes, liver and spleen are enlarged in Aplastic Anemia
False
Describe the colour and size of RBCs in Aplastic Anemia
Normochromic
Normocytic or
Macrocytic (MCV 95-110fl)
Is the reticulocyte count high or low in Aplastic Anemia
Low
The range in fall of granulocytes in Aplastic Anemia is usually below what value
1.5 x 10^9 / L
:
True or false
Neutrophil appears normal in Aplastic Anemia
True
In severe cases of Thrombocytopenia in Aplastic Anemia the values fall below what number
20 x 10^9 / L
Does Aplastic Anemia present with abnormal cells in peripheral blood
Nope!
In Aplastic Anemia the bone marrow shows hypoplasia, with loss of haemopoietic tissue which is replaced with what
Fat cells
What is the importance of the Trephine Biopsy
May show patchy cellular areas in a hypocellular background
What is the type of biopsy done to examine bone marrow and test for Aplastic Anemia
Trephine Biopsy
In the trephine biopsy of a pt with Aplastic Anemia, which cells are mainly present
Lymphocytes
Plasma cells
In the trephine biopsy of a pt with Aplastic Anemia, which cells are severely reduced or absent
Megakaryocytes
Severe cases of Aplastic Anemia show what percentage of Marrow cellularity
<25%
What is the peripheral blood criteria for Severe Aplastic Anemia
Granulocytes <0.5 x 10^9
Platelets < 20 x 10^9/l
Corrected retic count <1%
What is the criteria for Severe Aplastic Anemia based on Bone marrow trephine
Marked hypocellularity <25%
Moderate hypocellularity 25% -50%
List five tests used to help diagnose aplastic anemia
Liver function test to rule out hepatitis Urine hemosiderin Hams test Human leukocyte antigen Cytogenetics studies
Why is a liver function test done when diagnosing Aplastic anemia
To rule out hepatitis as the cause
Why is urine hemosiderin test done when diagnosing a plastic anemia
To rule out chronic intravascular hemolysis as the cause
What is Ham’s test
This is a blood test used to diagnose paroxysmal nocturnal hemoglobinuria PNH
What is the name of the blood test used to diagnose paroxysmal nocturnal hemoglobinuria
Ham’s test
Why is Ham’s test done when diagnosing aplastic anemia
To rule out paroxysmal nocturnal hemoglobinuria
What is the name of the blood test used to identify the best donor for bone marrow transplant
Human leukocyte antigen (HLA) typing
Why is human leukocyte antigen typing done when diagnosing aplastic anemia
To determine the best donor for a bone marrow transplant
List three examples of supportive management of patients with a plastic anemia
Packed red blood cell transfusion (ideally WBC depleted)
Platelet transfusion
Prevention/management of infections
List five examples of specific management for a plastic anemia
Stem cell transplant
Immunosuppressive therapy
Anabolic steroids
High dose methylprednisolone (immunosuppressive agent)
Granulocyte macrophage colony stimulating factor GM- CSF
Define stem cell transplant
It is the process by which normal haematopoiesis is establish by infusion of pluripotent stem cells to reestablish marrow function in a patient with defective or damaged bone marrow
List five types of stem cell transplant
Syngeneic Allogeneic related match Allogeneic unrelated match Partially mismatched related Autologous
Who is a Syngeneic blood donor
Identical twin
Who is an autologous blood donor
Self
What are three sources of stem cells
Peripheral blood stem cells PBSC
Bone marrow
Cord blood
List seven early complications of stem cell transplant
Nausea and vomiting Mucositis Diarrhea Aplasia Hemorrhagic cystitis Alopecia Hepatic Veno-occlusive disease
List four late complications of stem cell transplant
Stability
Growth disturbances
Cataracts
Second-degree malignancies
List three complications of stem cell transplant
Graft rejection
Graft versus host disease
Leukemic relapse
List seven differential diagnosis of pancytopenia
Aplastic anemia Megaloblastic anemia Bone marrow infiltration Myelofibrosis Hypersplenism Proximal nocturnal hemoglobinuria Myelodysplastic syndrome
Define Myelofibrosis
It is a rare type of blood cancer in which the bone marrow is replaced by fibrous scar tissue
Define pure red blood cell aplasia PRCA
It is a rare disorder of blood production in which the bone marrow fails to function in an adequate manner resulting in anemia
List one congenital cause of pure red blood cell aplasia PRCA
Diamond Blackfan Anemia
List four cause of Acquired Pure Red Cell Aplasia PRCA
Infection - parvovirus B 19
Thymoma
Hematological malignancies
Idiopathic
What is another name for a secondary anemia
Anemia of chronic disorder
List three causes of secondary anemia
Chronic infections
Inflammatory disorders
Malignancy
List five characteristic features of Pure Red Cell Aplasia PRCA
Interms of : colour, reticulocyte level, bone marrow invasion, severity
Normochromic normocytic or mildly hypochromic indices
Reticulocytes normal or decreased mild non-progressive anemia
Does not require bone marrow invasion
Severity depends on the disease activity
What is the morphology of the red blood cells in PRCA
Normochromic
Normocytic
Mildly hypochromic
What is the level of reticulocytes in PRCA
Normal or slightly decreased
When does PRCA usually develop
In the first few months of illness
What is the pathogenesis of PRCA
Cytokine mediated process Shortened RBC survival Impaired marrow response Abnormal iron metabolism TNF, IL-1 interferons
What is the treatment for PRCA
Treat the underlying cause
Erythropoietin can be used in some cases
What percentage of erythropoietin is produced in the renal cortex
90%
90% of erythropoietin is produced where
Renal cortex
What percent of erythropoeitin is produced in the liver
10%
10% of erythropoietin is produced in which organ
The liver
What is the stimulus for erythropoietin production in the kidney
Oxygen tension
What is the role of Erythropoietin
Increases the number of progenitor cells committed to erythropoiesis
What are the normal blood levels of erythropoietin
11-48 mU/mL ( milliunits per millilitre)
List seven indications for treatment of PRCA with Erythropoietin
Chronic renal failure Multiple myeloma Myelodysplastic syndrome Cancer chemotherapy Chronic diseases HIV AZT antiretroviral drug treatment
What is the dose of Erythropoietin administered per week To treat PRCA
150 units/kilograms three times per week
The maximum effect of PRCA with erythropoietin occurs in which week of treatment
4-8 week
What is the half time of erythropoietin
4 to 13 hours
Where is erythropoietin metabolized
By the liver
List five effects of treatment with erythropoietin
Depletion of iron stores Hypertension, edema Congestive cardiac failure Thrombosis, myocardial infarction, stroke Seizures, headaches
