Deficiency of red blood cells in the human body

1. Anemia
by: Mulugeta G. 1

2. Definition
• Anemia is a condition in which the amount of hemoglobin in a
patient’s circulatory system is reduced
• Functionally, anemia is defined as tissue hypoxia (inability of the
body to supply tissue with adequate oxygen for proper metabolic
function)
• This may result from decreased hemoglobin content or reduced red
cell number
by: Mulugeta G. 2

3. Causes of anemia
Anemia may be caused due to the following factors:
 Increased haemolysis - May be due to hereditary defects such
as spherocytosis, or sickle cells, which reduce the life span of
the red cell or may be acquired by the action of haemolytic
agents
 Diminished erythropiesis :
• Is either due to a nutritional deficiency or due to the bone
marrow failure
• The nutritional factors essential for erythropoiesis are iron
cobalt, Cobalt, Copper, vitamins B12 , vitamin C , protein and
some hormones
by: Mulugeta G. 3

4. Cont’d
 Blood loss
 May be brought about by trauma or acute or chronic disease
Hematologic Response to Anemia
 Tissue hypoxia causes increased renal release of
erythropoietin (EPO) to accelerate bone marrow
erythropoiesis
 The normal bone marrow can increase its activity 7-8 times
normal
 The marrow becomes hyper cellular due to a marked increase
in RBC precursors (called erythroid hyperplasia)
by: Mulugeta G. 4

5. Classification of anemia
• on the basis of the appearance of the red cells (morphological
classification) or physiological cause (etiological classification)
1) Morphological classification of anemia
• is based on RBC morphology
• Morphologically anemias are classified into:
Normocytic Normochromic
Microcytic hypochromic
Macrocytic Normochromic
by: Mulugeta G. 5

6. Normocytic Normochromic anemia
• Anemia due to decrease in the number of erythrocytes (due to
increased RBC loss or decreased RBC production)
• Characterized by normal MCV and normal MCHC
• These includes:
• Anemia of acute hemorrhage
• Aplastic anemias (those characterized by disappearance of
RBC precursors from the marrow)
• Anemia of chronic disease
• Hemolytic anemias (those characterized by accelerated
destruction of RBC’s)
by: Mulugeta G. 6

7. Microcytic Hypochromic anemia
• Characterized by low MCHC and low MCV
• Characterized by impaired hemoglobin synthesis
• Caused by inflammatory conditions, Toxic drugs & chemicals,
Malignance and Endocrine disorders
• These include:
• Iron deficiency anemia
• Sideroblastic anemia
• Thalassemia
• Anemia of chronic disease (rare cases)
by: Mulugeta G. 7

8. Macrocytic normochromic anemia
• Characterized by normal MCHC and high MCV
• Caused by Deficiency of vitamin B12 or folic acid, hepatic
disease(chronic liver diseases)
• Macrocytic Hypochromic Anaemia
• Characterized by high MCV and low MCHC
• Caused by deficiency of iron associated with deficiency of
vitamin B12 or folic acid
by: Mulugeta G. 8

9. ETIOLOGICAL CLASSIFICATION OF ANEMIA
• Anemia Resulting from excessive destruction of red cells
• Due to intracellular defects:
• Hereditary defects of red cell membrane (e.g. spherocytosis, ovalocytosis)
• Defect in globulin chain synthesis (e.g. thalassaemia)
• Due to extra cellular abnormalities
• Immune mechanism with demonstrable antibodies e.g. autoimmune
• Non-immune mechanism without demonstrable antibodies e.g. infections
agents which parasites RBCs as in malaria; bacterial toxins or haemolysins as
in clostridium per fringes, and toxic chemicals such as arsenic, lead are
responsible for destruction of red cells
• Decrease production of hemoglobin /Erythrocyte
by: Mulugeta G. 9

10. cont’d
• Anemia resulting from specific deficiency
• Vitamin B12 deficiency due to unbalanced diet, deficiency of intrinsic
factors or decreased absorption
• Iron deficiency due to increased loss of iron, increased requirement or
decreased intake due to defective diet or chronic malabsorption
• Anemia resulting from endocrine abnormalities
• Anemia resulting from inadequate marrow function
by: Mulugeta G. 10

11. Diagnosis of anemia
• The cause of anemia is identified with laboratory tests as well as
consideration of patient history and physical signs/clinical
symptoms
• Patient evaluation about nutritional and hydration status,
pregnancy, exposure to toxins or drugs and disease history (e.g
inflammation) are also very important
• Patient symptoms and anemia severity determine the need for a
blood transfusion treatment
by: Mulugeta G. 11

12. Thank you!
by: Mulugeta G. 12