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Haemolytic anaemias
Atifa Ambreen
Introduction
• Mean life span of a RBC-120days• Removed Extravascularly by- Macrophages of RE system.
Intravascular haemolysis occurs in some pathological disorders
Normal red blood cell breakdown.This takes place extravascularly in the macrophagesof the reticuloendothelilial system
Hemolytic Anemia
• Definition:– Those anemias which result from an increase in RBC destruction
• Classification:– Congenital / Hereditary– Acquired
Classification of Hemolytic Anemias
• Hereditary
Memeberane Hereditary spherocytosis,Hereditary elliptocytosis Metabolism G6PD Deficiency,pyruvate kinase deficiency Haemoglobin Genetic abnormalities(Hb S,Hb C,unstable)
Acquired
• Immune
Autoimmunewarm antibody typecold antibody type
Alloimmunehaemolytic transfusion reactionhaemolytic disease of newbornAllografts,especially stem cell transplantationDrug associated
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• Red cell fragmentation syndromes
March haemoglobinuriainfectionsMalaria,Clostridia
Chemical and physical agentsEspecially drugs,burns
Secondaryliver and renal disease
proxysmal nocturnal haemoglobinuria(PNH)
Laboratory evaluation of Haemolysis
• HEMATOLOGIC Extravascular Intravascular Routine blood film Polychromatophilia Polychromatophilia
• Reticulocyte count Increase increase• Bone marrow examination Erythroid Erythroid
hyperplasia hyperplasia
• PLASMA OR SERUM• Bilirubin unconjugated unconjugated• Haptoglobin Dec,Absent Absent• Plasma hemoglobin N/inc. Increase• Lactate dehydrogenase Variable increase
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• Extravascular Intravascular
• URINE• Bilirubin 0 0• Hemosiderin 0 +• Hemoglobin 0 + in severe
cases
Red Cell Membrane Defects
1.Hereditary Spherocytosis– Usually inherited as Autosomal Dominent disorder– Defect: Deficiency of Beta Spectrin or Ankyrin Loss of membrane in
Spleen & RES becomes more spherical Destruction in Spleen
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Clinical features
• Asymptomatic• Fluctuating hemolysis• Splenomegaly• Pigmented gall stones- 50%
Clinical course may be complicated with Crisis:
– Hemolytic Crisis: associated with infection– :Aplastic crisis associated with Parvovirus infection
Investigations
– Test will confirm Hemolysis– Periphral Smear: Spherocytes– Osmotic Fragility: Increased
Screen Family members
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• 2.Hereditary Elliptocytosis
Functional abnormality in one or more anchor proteins in RBC membrane- Alpha or beta spectrin , Protein 4.1
• Usually asymptomatic
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South-East Asian ovalocytosis:
• Caused by a nine amino acid deletion at he junction of the cytoplasmic and transmemberane domains of the band 3 protein
• Asymptomatic-usually• Cells oval , rigid ,resist invasion by malarial parasites• Common in malaysia , indonesia
Membrane abnormalities - Enzymopathies
• Deficiencies in Hexose Monophosphate Shunt– Glucose 6-Phosphate Dehydrogenase Deficiency
• Deficiencies in the EM Pathway– Pyruvate Kinase Deficiency
Glucose 6-Phosphate Dehydrogenase
• Regenerates NADPH, allowing regeneration of glutathione
• Protects against oxidative stress• Lack of G6PD leads to hemolysis during oxidative stress
– Infection– Medications– Fava beans
• Oxidative stress leads to Heinz body formation, extravascular hemolysis
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Investigations
– P. Smear: Bite cells, blister cells, irregular small cells, Heinz bodies, polychromasia
– G-6-PD level
2. Pyruvate Kinase Deficiency
– Deficient ATP production, Chronic hemolytic anemia
– Investigations• Priphral Smear: Prickle cells• Decreased enzyme activity
Autoimmune Hemolytic Anemia
• Result from RBC destruction due to RBC autoantibodies: Ig G, M, E, A
• Most commonly-idiopathic• Classification
– Warm Autoimmune haemolysis:Ab binds at 37degree Celsius– Cold Autoimmune haemolysis: Ab binds at 4 degree Celsius
1.Warm Autoimmune hymolysis
•Usually IgGIdiopathicSecondary causesSLE,CLL,lymphomas,Drugs(e.g.Methyldopa)
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MACROCYTE
SPHEROCYTE
IMMUNOHEMOLYTIC ANEMIA
Investigation
– e/o hemolysis, MCV – P Smear: Microspherocytosis, n-RBC– Confirmation: Coomb’s Test / Antiglobulin test
Direct Antiglobulin test
demonstrating the presence of autoantibodies or complement on the surface of the red blood cell.
Cold Autoimmune haemolysis
• Usually IgM
InfectionsMycoplasm pneumonia,infectiousmononucleosis lymphomaproxysmal cold haemoglobinuria
Investigation
• Periphral Smear: Microspherocytosis
Ig M with specificity to I or I Ag
Alloimmune
• Induced by red cell antigensHaemolytic transfusion reactionshaemolytic disease of the new bornpost stem cell graftsDrug inducedDrug-red cell membrane compleximmune complex
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