Lecture on Types of Anemia

Definition of Anemia

• Low oxygen carrying capacity of blood
• Can result from:
  • Low number of red blood cells
  • Dysfunctional red blood cells
• Detected via hematocrit as low PCV (Packed Cell Volume) or HCV (Hematocrit Volume) < 45%

Types of Anemia

1. Iron Deficiency Anemia

• Symptoms:
  • Shortness of breath (dyspnea)
  • Fatigue
  • Increased workload on the heart, leading to tachycardia
  • Dizziness, possible syncope
• Causes:
  • Blood loss (e.g., from ulcers)
  • Heavy menstruation (menorrhagia)
  • Low dietary iron (common in vegetarians)
• Pathophysiology:
  • Iron is crucial for hemoglobin production
  • Deficiency leads to low heme and hemoglobin levels
  • Results in microcytic anemia (MCV < 90 fL)
• Treatment:
  • Iron supplementation
  • Possible transfusions

2. Pernicious Anemia (B-12/Folic Acid Deficiency)

• B-12:
  • Important for DNA maturation in red blood cells
  • Deficiency often due to autoimmune lack of intrinsic factor
  • Leads to macrocytic anemia (MCV > 90 fL)
• Folic Acid:
  • Also needed for DNA maturation
• Treatment:
  • Intramuscular B-12 injections

3. Hereditary Spherocytosis

• Cause: Genetic mutations affecting spectrin or ankyrin proteins
• Effect:
  • Red blood cells become spherical, leading to hemolysis
  • Can cause splenomegaly
• Diagnosis: Coombs test

4. G6PDH Deficiency

• Enzyme: Glucose-6-phosphate dehydrogenase
• Pathophysiology:
  • Deficiency leads to reduced NADPH
  • Less protection against oxidative damage
  • Formation of Heinz bodies and hemolytic anemia

5. Sickle Cell Anemia

• Mutation:
  • Missense mutation changing glutamic acid to valine in hemoglobin
  • Causes sickle-shaped red blood cells when deoxygenated
• Complications:
  • Vaso-occlusive crisis
  • Splenomegaly, priapism
• Treatment:
  • Oxygen therapy, pain management, hydroxyurea
  • Possible resistance to malaria

6. Hemorrhagic Anemia

• Cause: Blood loss from trauma or conditions like peptic ulcers
• Treatment:
  • Surgical intervention
  • Blood transfusions

7. Aplastic Anemia

• Nature: Destruction of bone marrow affecting red blood cells, white blood cells, and platelets
• Symptoms: Pancytopenia (low counts of all blood cells)
• Causes:
  • Idiopathic, drug-induced, viral
• Treatment:
  • Bone marrow transplant, transfusions

8. Thalassemia

• Nature: Genetic condition affecting globin chain production
• Types:
  • Alpha Thalassemia: Missing alpha globin
  • Beta Thalassemia: Missing beta globin
• Effect: Microcytic anemia
• Treatment:
  • Frequent transfusions
  • Possible bone stem cell transplant

Special Considerations

• Splenectomy:
  • For severe cases of sickle cell anemia and hereditary spherocytosis
  • Risks include vulnerability to encapsulated bacteria

Conclusion

• Covered various types of anemia, their causes, symptoms, and treatments.
• Understanding the pathophysiology aids in appropriate management and treatment strategies.