Differential Diagnosis of Anemia PDF

Differential diagnosis of Anemia: 1. A complete blood count, CBC ∗ RBC count ∗ Hematocrit (Hct) or packed cell volume ∗ Hemoglobin determination ∗ RBC indices calculation ∗ Reticulocyte count 2. Blood smear examination to evaluate: -RBCs Size and Shape:...

Differential diagnosis of Anemia: 1. A complete blood count, CBC ∗ RBC count ∗ Hematocrit (Hct) or packed cell volume ∗ Hemoglobin determination ∗ RBC indices calculation ∗ Reticulocyte count 2. Blood smear examination to evaluate: -RBCs Size and Shape: Anisocytosis, & Poikilocytosis. -Leukocytes or Platelets abnormalities. 3. A bone marrow smear and biopsy to observe: – Maturation of RBC and WBC series – Presence of megakaryocytes – Ratio of myeloid to erythroid series. – Presence or absence of granulomas or tumor cells 4. Hemoglobin electrophoresis 5. Antiglobulin test: (Coomb’s test). 6. Osmotic fragility test. 7. Hb F test. 8. Sickling test. Red blood cell indices RBCs Indices: Part of the complete blood count (CBC) test. Used in diagnosis of anemia and it’s causes. The indices include: ❖ Mean corpuscular volume (MCV): is the average size of red blood cells and is calculated by dividing the hematocrit (Hct) by the red blood cells count. MCV = Hct / RBC Normal range: (78-98) fL (femto- is 10-15) Red blood cell indices ❖ Mean corpuscular hemoglobin (MCH): is the average amount of hemoglobin (Hb) per red blood cell and is calculated by dividing the hemoglobin by the red blood cell count. MCH = Hb / RBC Normal range: 27-32 pg/cell (pico- is 10-12) ❖ Mean corpuscular hemoglobin concentration (MCHC): is the average concentration of hemoglobin per Packed red blood cells and is calculated by dividing the hemoglobin by the hematocrit. Normal range:MCHC = Hb /(deci 30-35 g/dL Hct is 10-1) Morphological Classification of Anemia ∗ Based on RBC morphology and RBCs indices calculations: ∗ Anemia is divided into three groups: 1. Normocytic Normochromic anemia: (normal red cell indices) Blood loss anemia (Acute bleeding) Hemolytic anemia (except thalassaemia) Aplastic anemia Pure cell aplasia; Parvovirus B19-infection for erythroid cell after transfusion in sickle cell patients. 2. Microcytic hypochromic anemia: ( Low red cell indices) Iron deficiency anemia Sideroblastic anemia: X-linked genetic defect: delta-amino laevulinic acid synthase. Thalassemia Chronic diseases 3. Macrocytic Normochromic (high MCV and MCH, normal MCHC) Megaloblastic anemia (Vit. B12 deficiency & Folic acid deficiency). Liver disease, Others. Morphological Classification of Anemia 1. Normocytic Normochromic Anemia ◼ Is a condition in which the size & Hb content of each RBC is normal, but the number (count) of RBCs is decreased. ◼ It includes: Aplastic anemia due to BM failure or Pure RBCs aplasia. Blood loss anemia Hemolytic anemia A. Aplastic Anemia – Condition of blood pancytopenia caused by bone marrow failure…decreased production of all cell lines and replacement of marrow with fat. – Due to damaged stem cells, damaged bone marrow environment or suppression. Lab diagnosis of Aplastic Anemia: 1 Peripheral blood: Normochromic –Normocytic RBCs (normal MCV & MCH) Pancytopenia No abnormal cells 2- Bone marrow: ▪ Hypocellular BM with increased: - Fat spaces. - Lymph cells - Plasma cells - Macrophages - Mast cells B. Hemolytic anemia (H.A): Result from an increase in the rate of pre mature red cell destruction. It leads to – Erythropoietic hyperplasia – BM produces red cells 6 to 8 times the normal rate. – Marked reticulocytosis. Two main mechanisms for RBC destruction in HA – Intravascular hemolysis: in the circulation – Extravascular hemolysis: in RES (Reticulo-endothelial system).  Lab features of extravascular haemolysis: – Increased RBC break down Serum bilirubin increase Stool stercobilinogen increase Urine urobilinogen increase (dark urine) Lab features of intravascular haemolysis: – Hemoglobinemia and hemoglobinuria (dark urine). – Hemosiderinuria – Reduced/absent Serum haptoglobin. Types of Hemolytic anemia: 1. Hereditary hemolytic anemia Result of intrinsic red cell defects: Genetic defects: 1- Genetic mutant allele result in RBCs Membrane structural proteins defect ( Defective spectrin tetramers). A-Hereditary Spherocytosis: Spherocyte (Osmotic fragility test) B- Elliptocytosis: Cigar shaped RBCs. N 2-X-linked genetic mutant allele results in Metabolic defect: Example: G6PD deficiency. Denatured globin due to oxidants (free radicals) action; Heinz bodies formation; Removed by RES Macrophage; characteristic bite cells. Another cell that can be seen: basket cell. N 3-Inherited defect in hemoglobin gene (Beta-globin gene; Chr. 11): Example: Sickle cell anemia Valine substituted for glutamic acid at 6 th of ß-globin; production of abnormal hemoglobin ; Hb S. 1-Hemoglobin S Disease: HbSS: – Two sickle cell genes inherited (both beta abnormal). chains are – Symptomatic after 6 months of age. Target cell Laboratory findings: Sickle cell -CBC: Anemia, Sickle cells and target cells. HGB S Disease -Sickling test: Positive: (Hgb SS 2% sodium bisulfite → induce solution turbidity. ) -Hb electrophoresis: No Hb A, >80% Hb S, ↑ Hb F. n Hemoglobin S trait /Sickle cell trait /Hb SA: – No anemia or sickle cells. – Target cells present. – ~60% Hgb A, ~40% Hgb S Pattern of Sickle Hb Inheritance: N N 2. Acquired hemolytic anemia: A shortened survival of previously normal red cells. Result of extrinsic causes: 1 Immune Hemolytic anemia IHA: (Positive Coomb’s test; Direct Antiglobulin test). A-Warm IHA: Ex: Rh-incompatibility or SLE. B-Cold IHA: Cold-agglutinin syndrome: SDL: Pathophysiology, etiology, Laboratory findings. 2 Drug-induced HA: penicillin allergy. 3 Infection associated HA: Malaria.