HEMOLYTIC ANEMIAS

LEARNING OBJECTIVE 1. To compare and contrast intravascular and extravascular hemolysis 2. To acquire basic knowledge about the tests which are indicative of increased red cell destruction; increased red cell production 3. To emphasize on the peripheral and bone marrow changes seen in response to excessive red cell destruction

TYPES OF HAEMOLYSIS Intravascular haemolysis Extravascular haemolysis

INTRAVASCULAR HAEMOLYSIS - Mismatched blood Transfusion - Drug induced - Disseminated Intravascular Coagulation (DIC) - Paroxysmal nocturnal haemoglobinuria (PNH) - G 6-PD deficiency

EXTRAVASCULAR HAEMOLYSIS - Membrane defects (HS) - Immune haemolytic anaemia - Thalassaemia syndrome

LABORATORY TESTS FOR INCREASED RED BLOOD CELL DESTRUCTION EXTRAVASCULAR RED CELL DESTRUCTION Serum bilirubin - increased Serum heptoglobin - decreased Serum LDH - increased Increased urinary and fecal urobilinogen Bone marrow iron - increased

LABORATORY TESTS FOR INCREASED RED BLOOD CELL DESTRUCTION CONTD… INTRAVASCULAR RED CELL DESTRUCTION Serum bilirubin - increased Serum heptoglobin - decreased Serum LDH - Increased urinary and fecal urobilinogen Hemoglobinaemia and hemoglobinuria Methaemalbuminaemia Urinalysis - Hemosiderinuria Bone marrow iron stores - Decreased

LABORATORY TESTS FOR INCREASED RED BLOOD CELL PRODUCTION Reticulocytosis Bone marrow - Increased erythropoeisis Serum folate - decreased

LABORATORY FEATURES (MORPHOLOGICAL) SPECIALIZED TESTS: 1. SUPRA-VITAL STAIN - Reticulocytosis - Hb-H inclusions - Heinz bodies 2. COOMB’S TEST - Direct ( Antibody-coated red cells) - Indirect ( Serum antibodies)

LABORATORY FEATURES (MORPHOLOGICAL) CONTD.. 3. Osmotic fragility - Hereditary spherocytosis 4. G-6PD deficiency screening test 5. Hb-Electrophoresis - Thalassaemia syndromes

LABORATORY FEATURES (MORPHOLOGICAL) A. PERIPHERAL BLOOD FILM - Anisocytosis - Poikilocytosis - Polychromasia - Target cells - Schistocytosis(fragmented RBC,s) - Spherocytosis - Reticulocytosis

LABORATORY FEATURES (MORPHOLOGICAL) CONTD.. - Helmet cells - Bitten cells, triangle cells - Red cells inclusions: Heinz bodies Howell Jolly(H.J) bodies

LABORATORY FEATURES (MORPHOLOGICAL) CONTD.. B – BONE MARROW FINDINGS - Hypercellular - Erythroid hyperplasia - Megaloblastoid changes - Bone marrow – incresaed iron