Brief approach

1. Approach to hypochromic
microcytic anemias

2. Synopsis
• Definition
• Classification
• Iron deficiency anemia
• Sideroblastic anemia
• Anemia of chronic diseases
• Thalassemia
• Lead poisoning related anemia

3. Anemia
Functionally defined as a decrease in the competence of blood to carry oxygen to tissues ,
causing tissue hypoxia
WHO criteria

4. Classification of anemia
Morphological classification
Based on mean cell volume ( MCV)
• Microcytic - MCV < 80 fl /cell
• Macrocytic – MCV > 100fl/cell
• Normocytic - MCV 80-100fl /cell
Based on MCH and MCHC
• Hypochromic
• Hyperchromic

5. Microcytic hypochromic anemia
• Iron deficiency anemia
• Anemia of chronic diseases
• Thalassemia
• Sideroblastic anemia
• Long term lead intoxication

6. Iron deficiency anemia
Etiology
Decreased dietary intake and absorption - Eating disorders,Celiac disease, Bariatric surgery
Increased need - pregnancy , lactation , children
Increased loss - Hematemesis, Trauma related hemorrhage, Menorrhagia, vascular lesions

7. Specific findings
• Angular cheilitis – painful and inflamed fissures on one or both the corners of mouth
• Glossitis – Beefy red tongue
• Pica – eating disorder marked by eating non – food items
• Dysphagia
• Phagophagia – obsessive consumption of ice
• Koilonychia – spoon shaped concave nails

8. Investigations
Complete blood count
• ↓ Hb
• ↓ / Normal – reticulocyte
• ↓ MCV , MCH , MCHC
Blood smear
• Microcytic hypochromic
• Anisocytosis, poikilocytosis
• Target cells , pencil cells

9. Iron studies
• ↓ serum iron , ferritin
• ↓ transferrin saturation
• ↓ TIBC

10. Sideroblastic anemia
Etiology
• Altered mitochondrial function & defects in heme synthesis
• Hereditary and acquired
Symptoms
• Anemia
• Pallor
• Fatigability
• dyspnea

11. Investigations
Complete blood count
• Congenital – MCV - ↓/ normal
• Acquired - MCV - ↑ / normal
Blood smear
• Dimorphic anemia
• Anisopoikilocytosis
• Pappenheimer bodies

12. Bone marrow study
• Ring sideroblast
Iron studies
• ↑ serum iron
• ↑ transferrin saturation
• Normal / ↓ TIBC
• ↑ serum ferritin

13. Anemia of chronic diseases
Etiology
• Impaired iron release from macrophages due to increased hepcidin induced by
• Cytokines
• Inhibition of EPO production & impaired erythropoiesis
• Shortened erythrocyte survival
Associated systemic disease or chronic inflammatory conditions
Eg : Rheumatoid arthritis
Chronic kidney disease
TB / HIV / Malignancy

14. Investigations
Complete blood count
• Mild to moderate decrease in Hb
• Normal / ↓ MCV , MCHC
• Normal / ↑ RDW
• Leukocytosis
• ↑ ESR , CRP , IL -6
Peripheral smear
• Microcytic hypochromic / normocytic normochromic RBC’s

15. Iron studies
• ↓ serum iron levels
• ↑ ferritin
• ↓ serum transferrin saturation
• ↓ TIBC
Bone marrow study
• ↑ iron in macrophages , erythroid precursors

16. Thalassemia
Inherited hemoglobinopathies
Specific findings
• Fatigue with clinical features s/o anemia
• Splenomegaly
• Abnormal facies ( chipmunk facies)
• Frequent blood transfusions
• Hair on end appearance

17. Investigations
Complete blood count
• ↓ Hb
• ↓ MCV
• ↓ MCH
• ↑ RDW ( β thalassemia )
Peripheral blood smear
• Microcytic hypochromic
• Anisopoikilocytosis (Target cells)
• nRBC
• HbH inclusions ( α thalassemia )

18. Iron studies
• ↑ serum iron
• ↑ transferrin saturation
• ↑ serum ferritin
Others
• ↑ LDH
• ↑ indirect bilirubin
• ↓ haptoglobin

19. Lead poisoning related anemia
• Lead exposure / toxicity – Anemia
• Lead absorbed through lungs , GI tract , skin
Specific findings
• Peripheral neuropathy
• Interstitial nephritis
• Abdominal colic
• ADHD
• Burton’s line – thin , black -blue line visible along the margin of gums

20. Investigations
Complete blood count
• ↓MCV , MCH
Peripheral smears
• Microcytic hypochromic
• Basophilic stippling
• ↑ serum blood lead level
Others
• ↑ indirect bilirubin , LDH
• ↓ haptoglobin