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Macrocytic Anemia. Clinical pathology department SCU. Normal blood cells . Complete Blood Count (CBC). Normal red blood cells. Definition. An ( without ) - emia ( blood ): a reduction below normal in hemoglobin or red blood cell number. Symptoms and signs of Anemia. - PowerPoint PPT Presentation
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CLINICAL PATHOLOGY DEPARTMENTSCU
Macrocytic Anemia
Normal blood cells
Complete Blood Count (CBC)
Normal red blood cells
Definition
An (without) -emia (blood):
a reduction below normal in hemoglobin or red blood cell number
Symptoms and signs of Anemia
None if mildFatigueBreathlessnessDizzinesPale Skin & mucous membranesJaundice ( if hemolytic)Tachycardia
Differential Diagnosis Using MCV
Macrocytic anemias (MCV = 150 fl): > normal cells
Normocytic (MCV = 80-96 fl): cells are normal in volume
Microcytic anemias (MCV = 50 fl): cells are < normal
Macrocytic anemia
Defined as MCV > 100 femtolitersIdentified by peripheral blood smear or
automated RBC indices Smear is more sensitive in detecting early macrocytic
changes and small numbers of macrocytes Cell morphology can aid in determining etiology of
macrocytosis
Common Causes of Macrocytosis
cause % of casesAlcohol abuse 36%B12 or Folate deficiency 21%Chemotherapy or drugs 11%Hemolysis or bleeding 7%Liver disease 6%Primary bone marrow disorders 5%Hypothyroidism 5%Others 12%
Megaloblastic Anemia
Defective DNA synthesis leads to nuclear/cytoplasmic asynchrony
B12/folate deficiencyMacrocytic anemia with hypersegmented neutrophils
Megaloblastic Anemia
retarded DNA synthesis unimpaired RNA synthesis
BIG cells! immature nucleusmature cytoplasm
How is B12 involved?
B12 (and folate) are required for DNA synthesis.• Slowed DNA synthesis means big, immature nucleus• Cytoplasm (with RNA in it) matures just fine
B12 is also required for conversion of homocysteine to methionine• ↑ homocysteine = atherosclerosis!• ↓ methionine = subacute combined degeneration
Megaloblastic anemia
Megaloblastic anemia
Reticulocyte Count (In the Diagnosis of Anemia)
Useful in determining response and potential of bone marrow.
Reticulocytes are non-nucleated RBCs that still contain RNA.
Visualized by staining with supravital dyes, including new methylene blue or brilliant cresyl blue; RNA is precipitated as dye-protein complex.
Normal range is 0.5-2.0% of all erythrocytes. If bone marrow responding to anemia, should see
increases in retic count. Newborns have higher retic count than adults until
second or third week of life.
Retics Slide
Thank You