Anemia can be classified based on red blood cell size as microcytic, normocytic, or macrocytic. Microcytic anemias are caused by iron deficiency or thalassemia. Macrocytic anemia is usually megaloblastic due to vitamin B12 or folate deficiency. Normocytic anemias can result from bone marrow diseases, blood loss, or hemolysis. Specific causes of anemia include iron deficiency, B12 or folate deficiency, thalassemia, sickle cell anemia, autoimmune hemolytic anemia, and malaria. Laboratory tests and blood smears are used to classify and diagnose the underlying cause of anemia.

1. CLASSIFICATION OF
ANEMIA
Javid Iqbal
BSc(Hons)Medical Laboratory Technology
Trainee Technologist

2. Definition of Anemia
 Deficiency in the oxygen-carrying capacity
of the blood due to a diminished
erythrocyte mass.
 May be due to:
 Erythrocyte loss (bleeding)
 Decreased Erythrocyte production
 low erythropoietin
 Decreased marrow response to erythropoietin
 Increased Erythrocyte destruction
(hemolysis)

3. Measurements of Anemia
 Hemoglobin = grams of hemoglobin per 100 mL of
whole blood (g/dL)
 Hematocrit = percent of a sample of whole blood
occupied by intact red blood cells
 RBC = millions of red blood cells per microL of whole
blood
 MCV = Mean corpuscular volume
 If > 96 → Macrocytic anemia
 If 76 – 96→ Normocytic anemia
 If < 76 → Microcytic anemia
 RDW = Red blood cell distribution width
 = (Standard deviation of red cell volume ÷ mean cell
volume) × 100
 Normal value is 11-15%
 If elevated, suggests large variability in sizes of RBCs

4. Laboratory Definition of
Anemia
 Hgb:
 Women: <11.5
 Men: < 13.7
 Hct:
 Women: < 36
 Men: <41

5. Symptoms of Anemia
 Decreased oxygenation
 Exertional dyspnea
 Dyspnea at rest
 Fatigue
 Bounding pulses
 Lethargy, confusion
 Decreased volume
 Fatigue
 Muscle cramps
 Postural dizziness
 syncope

6. RBC Life Cycle
 In the bone marrow, erythropoietin
enhances the growth of differentiation of
burst forming units-erythroid (BFU-E) and
colony forming units-erythroid (CFU-E) into
reticulocytes.
 Reticulocyte spends three days maturing in
the marrow, and then one day maturing in
the peripheral blood.
 A mature Red Blood Cell circulates in the
peripheral blood for 100 to 120 days.
 Under steady state conditions, the rate of
RBC production equals the rate of RBC loss.

7. Classification of Anemia
 Anemia can be either acute or chronic.
 In acute anemia (sudden loss of blood), the lack of blood
volume in the circulatory system is more important than
the deficiency of hemoglobin. A loss up to 10% of blood
volume, as that taking place upon blood donation, is well
tolerated. Losses between 10 and 20% cause postural
hypotension, dizziness and faint. In losses above 20%,
there's tachycardia, cold extremities, extreme paleness
and hypotension, followed by shock; should the loss
surmount 30%, without immediate replacement of
intravenous fluids, the shock rapidly becomes
irreversible and fatal.
 In chronic anemia, there's no decrease in blood volume,
which is compensated by an increase in plasma volume

8. Classification of Anemia on
the Basis of MCV
 Microcytic anemia(MCV<76)
 Normocytic anemia(MCV=76-96)
 Macrocytic anemia(MCV>96)

9. Classification Based on
underlying Process
 Blood loss or def. of nutrients
 Hemolysis
 Failure of production

10. Classification of Anemia
 One way to classify anemia is by RBC size (i.e., MCV), as
microcytic, macrocytic, or normocytic. For the microcytic
anemias, the etiologic possibilities are iron deficiency,
thalassemia, sideroblastic anemia, and the anemias of chronic
disease. Severe microcytic anemia (MCV <70 fL) is caused
mainly by iron deficiency or thalassemia. Macrocytic anemia
may be the result of megaloblastic (folate or vitamin B12
deficiency) or nonmegaloblastic causes. Folate deficiency can in
turn be due to either reduced intake or diminished absorption.
Severe macrocytic anemia (MCV >96fL) is almost always
megaloblastic. In some rare cases, macrocytic anemia is
related to the myelodysplastic syndromes prior to or after
chemotherapy.
 The causes of normocytic anemias include aplastic anemia,
bone-marrow replacement, pure red-cell aplasia, anemias of
chronic disease, hemolytic anemia, and recent blood loss. A
number of anemias have a genetic etiology. Examples of such
inherited disorders include hereditary spherocytosis and
sickle-cell (SC) anemia

12. Hypochromic Microcytic Anemia
Microcytic anemias
the etiologic possibilities are
 Iron deficiency
 Thalassemia
 Sideroblastic anemia
 Anemias of chronic disease.
Severe microcytic anemia (MCV <76 fL) is
caused mainly by iron deficiency or thalassemia.

13. Iron Deficiency Anemia

14. Iron Deficiency Anemia -
koilonychia

15. Iron Deficiency Anemia – Lab
Findings
 Serum Iron
 LOW (< 60 micrograms/dL)
 Total Iron Binding Capacity (TIBC)
 HIGH ( > 360 micrograms/dL)
 Serum Ferritin
 LOW (< 20 nanograms/mL)
 Can be “falsely”normal in inflammatory
states

16.  TEST Iron def ThalMin An of ch dis
 S.Iron - low normal normal
 S.Ferritin - low N/H N/H
 Marrow iron - low N/H N/H
 Hb A2 or F - N H=Bthal N
 N=Athal
 RDW - high normal N/H

17. Thalassemia
 Microcytic anemia
 Defects in either the alpha or beta chains of
hemoglobin, leading to ineffective
erythropoiesis and hemolysis
 α-thalassemia:
 Prevalent in Africa, Mediterranean, Middle
East, Asia
 β-thalassemia:
 Prevalent in Mediterranean, South East
Asia, India, Pakistan
 Smear shows microcytosis with target cells

18. Thalassemia

19. Normochromic Normocytic
Anemia
 Chronic inflammatory disease—
(1)infection (2)collagen vascular disease
(3)inflammatory bowel disease
 Recent blood loss
 Malignancy/Marrow infiltration
 Chronic renal failure
 Transient erythroblastopenia of chidhood
 Marrow aplasia/hypoplasia
 HIV infection

20.  The causes of normocytic anemias include aplastic
anemia, bone-marrow replacement, pure red-cell
aplasia, anemias of chronic disease, hemolytic anemia,
and recent blood loss. A number of anemias have a
genetic etiology. Examples of such inherited disorders
include hereditary spherocytosis, sickle-cell (SC) anemia,
and thalassemia

21. Normochromic Normocytic

22. Macrocytic Anemia
 Megaloblastic anemias
• Vit.B12 def. - (1) pernicious anemia
(2) malabsorption
• Folate def. - (1) malnutrition (2) malabsorption
(3) chronic hemolysis (4)drugs - phenytoin, sulfa
 Hemolysis
 Myelodysplastic syndrome
 Marrow failure - Aplastic anemia
 Chronic liver disease
 Hypothyroidism

23. Vitamin B12 Deficiency

24.  Macrocytic anemia may be the result of megaloblastic
(folate or vitamin B12 deficiency) or nonmegaloblastic
causes. Folate deficiency can in turn be due to either
reduced intake or diminished absorption. Severe
macrocytic anemia (MCV >125 fL) is almost always
megaloblastic.

25. Folate Deficiency

26. Vitamin B12 Deficiency Versus
Folate Deficiency
Vitamin B 12
Deficiency
Folate Deficiency
MCV > 100 > 100
Smear Macrocytosis with
hypersegmented
neutrophils
Macrocytosis with
hypersegmented
neutrophils
Pernicious anemia Yes NO
Homocystine Elevated Elevated
Methylmalonic Acid Elevated NORMAL

27. Anemia due to Destruction of
Red Blood Cells
 Hemoglobinopathies
 Sickle Cell Anemia
 Aplastic Anemia
 Decrease in all lines of cells – hemoglobin,
hematocrit, WBC, platelets
 Parvovirus B19, EBV, CMV
 Acquired aplastic anemia
 Hemolytic Anemia

28. Hemolytic Anemias
 Hereditary spherocytosis
 Glucose-6-phosphate
dehydrogenase (G6PD)
Deficiency
 Most common enzyme defect in
erythrocytes
 X-linked
 Brisk hemolysis when patients
exposed to oxidative stress from
drugs, infections or toxins.
 Thrombotic Thrombocytopenic
Purpura (TTP)
 Thrombocytopenia and
microangiopathic hemolytic
anemia, fever, renal
insufficiency, neurologic
symptoms
 Schistocytes on smear
 Hemolytic Uremic Syndrome
 Thrombocytopenia,
Microangiopathic hemolytic
anemia, renal insufficiency
 Autoimmune Hemolytic Anemia
 Warm-antibody mediated
 IgG antibody binds to erythrocyte
surface
 most common
 Diagnosed by POSITIVE Coomb’s
Test (detectgs IgG or complement
on the cell surgace)
 Can be caused drugs
 Treated with corticosteroids or
splenectomy if refractory
 Cold agglutinin Disease
 IgM antibodies bind to erythrocyte
surface
 Does not respond to corticosteroids,
but usually mild.
 Infections
 Malaria
 Babesiosis
 Sepsis
 Trauma
 Includes some snake, insect bites

29. Sickle Cell Anemia

30. Spherocytosis

31. Malaria