Anemais

Overview of Anemias

Definition: A condition characterized by a decrease in the number of red blood cells (RBCs) or a decrease in the concentration of hemoglobin (HGB) in the blood, resulting in reduced oxygen-carrying capacity
Symptoms: Fatigue, weakness, pallor (pale skin), shortness of breath, dizziness, headache, and tachycardia
Diagnosis: Based on a combination of clinical evaluation, complete blood count (CBC), peripheral blood smear, and other laboratory tests

Morphological Classification: Based on RBC size (Mean Corpuscular Volume - MCV) and hemoglobin content (Mean Corpuscular Hemoglobin Concentration - MCHC)
- Microcytic Anemias: Small RBCs (MCV < 80 fL)
  - Impaired hemoglobin synthesis
- Normocytic Anemias: Normal-sized RBCs (MCV 80-100 fL)
  - Can be due to a variety of causes, including acute blood loss, hemolysis, or bone marrow disorders
- Macrocytic Anemias: Large RBCs (MCV > 100 fL)
  - Impaired DNA synthesis or abnormal RBC maturation
Pathophysiological Classification: Based on the underlying mechanism causing the anemia
- Decreased RBC Production:
  - Bone marrow disorders
  - Nutritional deficiencies
  - Chronic diseases
- Increased RBC Destruction (Hemolytic Anemias):
  - Inherited RBC disorders
  - Acquired hemolytic anemias
- Blood Loss:
  - Acute or chronic blood loss

Complete Blood Count (CBC):
- Hemoglobin (HGB)
- Hematocrit (HCT)
- Red Blood Cell Count (RBC)
- Mean Corpuscular Volume (MCV)
- Mean Corpuscular Hemoglobin (MCH)
- Mean Corpuscular Hemoglobin Concentration (MCHC)
- Red Cell Distribution Width (RDW)
- White Blood Cell Count (WBC) and Differential
- Platelet Count
Peripheral Blood Smear:
- RBC morphology (size, shape, color)
- WBC differential
- Platelet estimate
Reticulocyte Count:
- Percentage and absolute number of reticulocytes
- Corrected Reticulocyte Count/Reticulocyte Production Index (RPI)
Iron Studies:
- Serum Iron
- Total Iron-Binding Capacity (TIBC)
- Transferrin Saturation
- Ferritin
Vitamin B12 and Folate Levels:
- Serum B12
- Red Blood Cell Folate
Methylmalonic Acid (MMA) and Homocysteine Levels:
- Elevated in B12 Deficiency
- Homocysteine also Elevated in Folate Deficiency
Hemoglobin Electrophoresis:
- Identifies abnormal hemoglobin variants (e.g., HbS, HbC)
Direct Antiglobulin Test (DAT):
- Detects antibodies or complement proteins on the surface of RBCs
Bone Marrow Examination:
- Cellularity
- Maturation of cell lines
- Presence of abnormal cells
Other Tests:
- Haptoglobin and LDH (for hemolysis)
- Coombs test (for autoimmune hemolytic anemia)
- Osmotic Fragility Test (for hereditary spherocytosis)
- G6PD Assay (for G6PD deficiency)

Anemia: Deficiency of red blood cells or hemoglobin
Microcytic: Small red blood cells (MCV < 80 fL)
Normocytic: Normal-sized red blood cells (MCV 80-100 fL)
Macrocytic: Large red blood cells (MCV > 100 fL)
Hypochromic: Decreased hemoglobin content (pale color)
Hyperchromic: Increased hemoglobin content (intensely colored)
Reticulocyte: Immature red blood cell
Hemolysis: Destruction of red blood cells
Extramedullary Hematopoiesis: Blood cell production outside the bone marrow
Pancytopenia: Deficiency of all blood cell lines (RBCs, WBCs, platelets)
Megaloblastic: Abnormal maturation of blood cells due to impaired DNA synthesis