Hemolytic Anemia Classification - By Thejus K. Thilak
HEMOLYTIC ANAEMIA BY THEJUS.K.THILAK
HEMOLYTIC ANEMIASHemolytic anemias = reduced red-cell life span
Hemolytic Anemia Definition: Those anemias which result from an increase in RBC destruction Classification: Congenital / Hereditary Acquired
Mechanisms of hemolysis: - intravascular - extravascular
Inravascular hemolysis (1):- red cells destruction occurs in vascular space- clinical states associated with Intravascular hemolysis: acute hemolytic transfusion reactions severe and extensive burns paroxysmal nocturnal hemoglobinuria severe microangiopathic hemolysis physical trauma bacterial infections and parasitic infections (sepsis)
Inravascular hemolysis (2):- laboratory signs of intravascular hemolysis: indirect hyperbilirubinemia erythroid hyperplasia hemoglobinemia methemoalbuminemia hemoglobinuria absence or reduced of free serum haptoglobin hemosiderynuria
Laboratory features:1. Laboratory features - normocytic/macrocytic, hyperchromic anemia - reticulocytosis - increased serum iron - antiglobulin Coombs’ test is positive2. Blood smear - anisopoikilocytosis, spherocytes - erythroblasts - schistocytes3. Bone marrow smear - erythroid hyperplasia
3. PNH –laboratory features: - pancytopenia - chronic urinary iron loss - serum iron concentration decreased - hemoglobinuria - hemosiderinuria - positive Ham’s test (acid hemolysis test) - positive sugar-water test - specific immunophenotype of erytrocytes (CD59,CD55)4. Treatment: - washed RBC transfusion - iron therapy - allogenic bone marrow transplantation
Introduction Mean life span of a RBC-120days Removed Extravascularly by- Macrophages of RE system
Classification of Hemolytic AnemiasHereditary 1. Abnormalities of RBC interior a.Enzyme defects: G-6-PD def,PK def b.Hemoglobinopathies 2. RBC membrane abnormalities a. Hereditary spherocytosis etc. b. PNHAcquired c. Spur cell anemia 3. Extrinsic factors a. Hypersplenism b. Antibody: immune hemolysis c. Mechanical trauma: MAHA d. Infections, toxins, etc Ref : Harrison’s
Features of HEMOLYSIS Bilirubin LDH Reticulocytes, n-RBC Haptoglobulins +ve Urinary hemosiderin, Urobilinogen Blood Film Spherocytes No spherocytes FragmentationDCT +ve DCT –veAI Hemolysis H. Sherocytosis Malaria, Clostidium Hereditery enzymopathies Microangiopathic, Traumatic
Red Cell Membrane Defects1.Hereditary Spherocytosis Usually inherited as AD disorder Defect: Deficiency of Beta Spectrin or Ankyrin Loss of membrane in Spleen & RES becomes more spherical Destruction in Spleen
Complications Clinical course may be complicated with Crisis: Hemolytic Crisis: associated with infection Aplastic crisis: associated with Parvovirus infection
Inv: Test will confirm Hemolysis P Smear: Spherocytes Osmotic Fragility: Increased Screen Family members
Management: Folic Acid 5mg weekly, prophylaxis life long Spleenectomy Blood transfusion in Ac, severe hemolytic crisis
2.Hereditary Elliptocytosis Equatorial Africa, SE Asia AD / AR Functional abnormality in one or more anchor proteins in RBC membrane- Alpha spectrin , Protein 4.1 Usually asymptomatic Mx: Similar to H. spherocytosis Variant: 3.SE-Asian ovalocytosis: Common in Malaysia , Indonesia… Asymptomatic-usually Cells oval , rigid ,resist invasion by malarial parasites
Red Cell Enzymopathies Physiology: EM pathway: ATP production HMP shunt pathway: NADPH & Glutathione production
1. Glucose-6-Phosphate Dehydrogenase ( G6PD ) Deficiency Pivotalenzyme in HMP Shunt & produces NADPH to protect RBC against oxidative stress Most common enzymopathy -10% world’s population Protection against Malaria X-linked
Autoimmune Hemolytic Anemia Result from RBC destruction due to RBC autoantibodies: Ig G, M, E, A Most commonly-idiopathic Classification Warm AI hemolysis:Ab binds at 37degree Celsius Cold AI Hemolysis: Ab binds at 4 degree Celsius
1.Warm AI Hemolysis: Can occurs at all age groups F>M Causes: 50% Idiopathic Rest - secondary causes: 1.Lymphoid neoplasm: CLL, Lymphoma, Myeloma 2.Solid Tumors: Lung, Colon, Kidney, Ovary, Thymoma 3.CTD: SLE,RA 4.Drugs: Alpha methyl DOPA, Penicillin , Quinine, Chloroquine 5.Misc: UC, HIV
Inv: e/o hemolysis, MCV P Smear: Microspherocytosis, n-RBC Confirmation: Coomb’s Test / Antiglobulin test Treatment Correct the underlying cause Prednisolone 1mg/kg po until Hb reaches 10mg/dl then taper slowly and stop Transfusion: for life threatening problems If no response to steroids Spleenectomy or, Immunosuppressive: Azathioprine, Cyclophosphamide
2. Cold AI Hemolysis Usually Ig M Acute or Chronic form Chronic: C/F: Elderly patients Cold , painful & often blue fingers, toes, ears, or nose ( Acrocyanosis) Inv: e/o hemolysis P Smear: Microspherocytosis Ig M with specificity to I or I Ag
Other causes of Cold Agglutination: Infection: Mycoplasma pneumonia, Infec Mononucleosis PCH : Rare cause seen in children in association with cong syphilis
Treatment: Treatment of the underlying cause Keep extremities warm Steroids treatment Blood transfusion
Non-Immune Acquired Hemolytic Anemia1. Mechanical Trauma A). Mechanical heart valves, Arterial grafts: cause shear stress damage B).March hemoglobinuria: Red cell damage in capillaries of feet C). Thermal injury: burns D). Microangiopathic hemolytic anemia (MAHA): by passage of RBC through fibrin strands deposited in small vessels disruption of RBC eg: DIC,PIH, Malignant HTN,TTP,HUS
Acquired hemolysis2.Infection F. malaria: intravascular hemolysis: severe called ‘Blackwater fever’ Cl. perfringens septicemia3.Chemical/Drugs: oxidant denaturation of hemoglobin Eg: Dapsone, sulphasalazine, Arsenic gas, Cu, Nitrates & Nitrobenzene
Paroxysmal Nocturnal Hemoglobinuria Hematopoietic stem cell disorder Mutation of phosphatidylinositol glycan class A (PIG-A) gene Glycosylphosphatidylinositol (GPI) anchors membrane proteins Without GPI, unable to regulate completment activities on membrane Hemolysis is pH dependent Thrombosis can occur
Lab Tests for PNH Acidified serum lysis test (Ham’s test): PNH cells lyse due to complement activation in acidified serm Sugar water (sucrose hemolysis) test: RBCs sensitive to complement will lyse in sucrose and serum Flow cytometry: lack of CD59 on RBCs, or lack of CD59 or CD55 on granulocytes
Microangiopathy Schistocytes Triangular or helmet shaped RBC fragments Destruction of RBC as they move through damaged blood vessels Endocarditis Hemangiosarcoma Caval Syndrome – Heartworm Disease Thrombosed IV catheter Vasculitis Hemolytic-uremic syndrome DIC Schistocytes are also seen with osmotic fragility Liver disease, iron deficiency, water intoxication, congenital, zinc toxicity
Young man of 19 Complains of giddiness weakness, pallorExamination reveals a spleen mild lemon yellow sclera
The direct antiglobulin test waspositive for complement (C3d) (++),and IgG (++-).Also was positive for agglutinins ofIgM type and had a titer of 1:1024.
complementDirect antiglobulin testdemonstrating the presence of autoantibodies (shownhere) or complement on the surface of the red bloodcell.
Serologies for humanimmunodeficiency virus, hepatitis Band C viruses, and Mycoplasmapneumoniae were negative.Rheumatoid factor and antinuclearantibodies were undetectable.
Prednisone therapy was started at a dose of 1 mg/kg intravenously, daily. Hemoglobin level rose to 11 g/dL, concomitantly with the improvement of hemolytic signs.
A reduction of positivity of bothdirect and indirect antiglobulin tests(polyvalent serum + ; C3d + ;IgG+ ), as well as a reduction ofcold agglutinin titers (1:128), wasobserved 8 weeks aftercorticosteroid therapy.
Three months later, corticosteroidswere tapered to a maintenancedose of 25 mg daily.Hemolysis recurred again with thefall of hemoglobin to 7 g/dL.
The direct antiglobulin test recurredpositive for polyvalent serum (+++),complement (+++), and IgG (+++),while cold agglutinin titers againbecame strongly positive (1:256).
Immunophenotyping of bonemarrow cells showed that 10% ofall the cells were CD20 and CD19positive.
CD20 is widely expressed on B-cells.CD20 could play a role in Ca2+influx across plasma membranes,maintaining intracellular Ca2+concentration and allowingactivation of B cells.
Hemoglobin value reached13.5 g/dL just before the third dose,although biochemical signs ofhemolysis remained substantiallyunaltered.
At the end of therapy, the hemolytic signs disappeared, the direct and indirect antiglobulin tests becamenegative, and cold agglutinin titers fell to 1:32 Immunophenotyping of bonemarrow cells showed the absence of CD20 and CD19 B cells.