Anemia is a condition where the number of red blood cells (RBCs) is decreased. It can be caused by decreased RBC production, blood loss, or RBC destruction. The causes can be diseases that need to be treated directly or secondary manifestations of other conditions. Laboratory tests like complete blood counts, peripheral smears, and reticulocyte counts help classify and diagnose anemia based on RBC size and production rates. Anemias are classified as microcytic, normocytic, or macrocytic depending on mean corpuscular volume. Specific causes are then evaluated based on additional laboratory findings.

1. Anemia - Introduction

2. Normal Erythropoiesis
Kidney Bone marrow Multi-potent
stem cell
Epo
mRNA Erythroid
stem cell
Epo
Oxygen
sensor
3-4
days
Blood vessel
Peripheral
blood
RBC survival
100-120 days

7. Anemia
• Understanding anemia
– Disease - to be treated on its own merits
– Condition - a secondary manifestation of
another disease
– Symptoms depend on severity/acuity
• Causes
– Decreased production
– Blood loss
– Hemolysis

8. Laboratory Evaluation of Anemia
• Complete blood count
• Peripheral smear
• Reticulocyte count
– Relative reticulocyte count
♦ Percent of all RBC (normal 0.8%–1.5%)
– Absolute reticulocyte count
♦ Relative reticulocyte count x RBC count
♦ Normal 50,000–75,000/µl
♦ Examples: 6
1.1% x 4.96 x10 = 55,000/l
6
12.2% x 2.05 x10 = 250,000/l

9. Classification of Anemia Based on
RBC Kinetics and Size
MCV
Microcytic Normocytic Macrocytic
Retic Low Common Common Common
count
High Uncommon Common Uncommon

10. Microcytic Hypochromic Anemia:
Diagnosis
• Mild (MCV > 70 fl) • Severe (MCV < 70 )
– Iron deficiency – Iron deficiency
– Thalassemia – Thalassemia
– Lead toxicity
– Sideroblastic anemia
– Anemia of chronic
disease

11. Macrocytic Anemia with Low
Reticulocyte Count
• Megaloblastic anemia
– Vitamin B12 deficiency
– Folate deficiency
• Non-megaloblastic macrocytic anemia
– Liver disease
– Hypothyroidism
– Drug-induced (DNA synthesis block)
– Myelodysplastic syndrome