ACQUIRED ACQUIRED HEMOLYTIC ANEMIAS.HEMOLYTIC ANEMIAS.

Are mostly due to extra Are mostly due to extra corpuscular or environmental corpuscular or environmental

changes.changes.

CausesCauses

Hypersplenism (entrapment )Hypersplenism (entrapment ) Immune causes Immune causes

Warm reactive(IgG) antibody.Warm reactive(IgG) antibody. Cold reactive (IgM ) antibody Cold reactive (IgM ) antibody

(cold agglutinin disease) (cold agglutinin disease) Cold reactive (IgG) antibody. Cold reactive (IgG) antibody.

(paroxysmal cold hemoglobinuria)(paroxysmal cold hemoglobinuria)

Drug dependent antibody.Drug dependent antibody. Auto immune.Auto immune. Hapten.Hapten.

Traumatic hemolytic anemia.Traumatic hemolytic anemia. Impact hemolysis. Impact hemolysis. Macro vascular defects –ProsthesesMacro vascular defects –Prostheses Micro vascular causes.Micro vascular causes.

• Thrombotic thrombocytopenic purpura.Thrombotic thrombocytopenic purpura.• Hemolytic uremic syndrome.Hemolytic uremic syndrome.• Disseminated intravascular hemolysis.Disseminated intravascular hemolysis.• Other causes of microvascular abnormalities.Other causes of microvascular abnormalities.

Hemolytic anemia due toxic effects on the Hemolytic anemia due toxic effects on the membrane.membrane. Spur cell anemiaSpur cell anemia External toxinsExternal toxins

• Animal or spider bites.Animal or spider bites.• Metals (e.g.,copper)Metals (e.g.,copper)• Organic compounds.Organic compounds.

Paroxysmal nocturnal hemoglobinuria.Paroxysmal nocturnal hemoglobinuria.

HYPERSPLENISM HYPERSPLENISM

sequestration of cells in the spleen sequestration of cells in the spleen causing cytopenia.causing cytopenia.

In the face of splenomegaly, there is In the face of splenomegaly, there is increased destruction of the cells of the increased destruction of the cells of the blood in a relatively nutrient poor blood in a relatively nutrient poor environment full of phagocytic cells.environment full of phagocytic cells.

HYPERSPLENISMHYPERSPLENISM

Normally 30% of total platelets are sequestered Normally 30% of total platelets are sequestered in the spleen and come out when needed if there in the spleen and come out when needed if there is bleeding or infection is bleeding or infection

Normal spleen does not store or sequester Normal spleen does not store or sequester RBC’sRBC’s

Hypersplenism is characterised by Hypersplenism is characterised by CytopeniasCytopenias SplenomegalySplenomegaly Hyperplastic BonemarrowHyperplastic Bonemarrow

Cytopenias result due to increased distruction Cytopenias result due to increased distruction of RBC, WBC & Platelets secondary to of RBC, WBC & Platelets secondary to reduced flow of blood through enlarged and reduced flow of blood through enlarged and congested cords ( congestive splenomegaly ) congested cords ( congestive splenomegaly ) or can be due to immune mediated or can be due to immune mediated mechanisms as the enlarged spleen has mechanisms as the enlarged spleen has abundant phagocytes abundant phagocytes

IMMUNE HEMOLYTIC IMMUNE HEMOLYTIC ANEMIASANEMIAS

Auto immune hemolytic anemias.(AIHAs)Auto immune hemolytic anemias.(AIHAs) Due to antiboby production by the body Due to antiboby production by the body

against its own RBCs.against its own RBCs. Characterised by a positive direct Characterised by a positive direct

antiglobulin test (DAT) also known as the antiglobulin test (DAT) also known as the Coombs test.Coombs test.

Divided into warm and cold types according Divided into warm and cold types according to whether the antibody reacts more to whether the antibody reacts more strongly with red cells at 37strongly with red cells at 37ooc or 4c or 4ooc.c.

Warm antibody immuno hemolytic anemiaWarm antibody immuno hemolytic anemia these anbtibodies react at body temperature these anbtibodies react at body temperature

(37(37ooC)C) Occurs at all ages.Occurs at all ages. More common in adult women.More common in adult women. 25% of patients have an underlying lymphoid 25% of patients have an underlying lymphoid

neoplasm.neoplasm. The antibodies are nearly always IgG, rarely The antibodies are nearly always IgG, rarely

IgM or IgA. IgM or IgA.

May occur secondary to SLE where the RBCs May occur secondary to SLE where the RBCs are typically coated with IgG and C3are typically coated with IgG and C3

When associated with ITP (auto immune When associated with ITP (auto immune thrombocytopenia) it is known as Evans thrombocytopenia) it is known as Evans syndrome.syndrome.

It may occur as a result of some drugs which It may occur as a result of some drugs which may stimulate antibody formation (eg., may stimulate antibody formation (eg., methyldopa)methyldopa)

Mild form.Mild form. Patients are asymptomatic.Patients are asymptomatic. Only there is a positive direct Coombs test.Only there is a positive direct Coombs test. There is insufficient antibody present on the There is insufficient antibody present on the

RBC surface to permit the RE system to RBC surface to permit the RE system to recognise the red blood cell as abnormal.recognise the red blood cell as abnormal.

Moderate form.Moderate form. Patients have moderate anemia. Patients have moderate anemia.

(Hb -6 to 10 gms% ) (Hb -6 to 10 gms% ) Positive direct Coombs test.Positive direct Coombs test. Reticulocytosis of about 10 to 30%.Reticulocytosis of about 10 to 30%. Spherocytosis.Spherocytosis. Splenomegaly.Splenomegaly. Venous thrombosis occasionally.Venous thrombosis occasionally.

Severe form.Severe form. There is severe hemolysis associated with There is severe hemolysis associated with

hemoglobinemia,hemoglobinuria and shock.hemoglobinemia,hemoglobinuria and shock. Rapidly fatal if not treated aggressively.Rapidly fatal if not treated aggressively.

COOMBS TEST.COOMBS TEST. Major tool for diagnosing autoimmune Major tool for diagnosing autoimmune

hemolysis.hemolysis.

The direct coombs test detects IgG or C3 The direct coombs test detects IgG or C3 on the RBCs of the patient which indicates on the RBCs of the patient which indicates the presence of immune hemolysis the presence of immune hemolysis

The coombs reagent may be broad The coombs reagent may be broad spectrum or it may be specifically directed spectrum or it may be specifically directed against IgG, IgM, IgA, or C3d (complement)against IgG, IgM, IgA, or C3d (complement)

The test is positive if the RBCs agglutinate.The test is positive if the RBCs agglutinate.

The antibodies both on the red cell surface The antibodies both on the red cell surface and free in the serum are best detected at and free in the serum are best detected at 3737ooC.C.

Rarely neither IgG nor complement(C3) Rarely neither IgG nor complement(C3) maybe found on the RBC of the patient maybe found on the RBC of the patient (Coombs negative IHA)(Coombs negative IHA)

WARM ANTIBODY IMMUNOHEMOLYTIC WARM ANTIBODY IMMUNOHEMOLYTIC ANEMIA.ANEMIA.

Causes:Causes: Idiopathic.Idiopathic. LymphomasLymphomas

• Chronic lymphocytic leukemiaChronic lymphocytic leukemia• Non Hodgkins lymphomaNon Hodgkins lymphoma• Hodgkins disease (infrequent)Hodgkins disease (infrequent)

SLE and other collagen vascular diseases.SLE and other collagen vascular diseases. DrugsDrugs

• methyl dopa (autoantibody to Rh antigens)methyl dopa (autoantibody to Rh antigens)• Penicillin type(stable hapten)Penicillin type(stable hapten)• Quinidine type(unstable hapten) Quinidine type(unstable hapten)

Post viral infections.Post viral infections. Other tumors (rare)Other tumors (rare)

PATHOGENESISPATHOGENESIS

In warm antibody IHA, the RBCs are usually coated with In warm antibody IHA, the RBCs are usually coated with IgG alone or with complement and are therefore taken IgG alone or with complement and are therefore taken up by RE macrophages which have receptors for the up by RE macrophages which have receptors for the IgFc fragment.IgFc fragment.

Part of the coated RBC membrane is lost and the cell Part of the coated RBC membrane is lost and the cell becomes progressively more spherical to maintain the becomes progressively more spherical to maintain the same volume and is ultimately destroyed prematurely in same volume and is ultimately destroyed prematurely in the spleen predominantlythe spleen predominantly

When the cells are coated with IgG and complement or When the cells are coated with IgG and complement or complement alone,RBC destruction occurs more complement alone,RBC destruction occurs more generally in the RE system.generally in the RE system.

TREATMENTTREATMENT

If mild hemolysisIf mild hemolysis no treatment is required.no treatment is required. Remove the underlying cause.Remove the underlying cause.

If significant hemolysisIf significant hemolysis Treat with Prednisolone(1mg/kg/day)Treat with Prednisolone(1mg/kg/day) Hb rises within 3 or 4 days and in most by 1 to Hb rises within 3 or 4 days and in most by 1 to

2 weeks.2 weeks. Continue till Hb is risen to normal and then Continue till Hb is risen to normal and then

taper to 20mg/day and subsequently taper taper to 20mg/day and subsequently taper gradually.gradually.

Prednisolone acts by inhibiting the Prednisolone acts by inhibiting the phagocytosis of the IgG coated RBC and by phagocytosis of the IgG coated RBC and by inhibiting antibody synthesis.inhibiting antibody synthesis.

SplenectomySplenectomy in patients who fail to respond to prednisolone in patients who fail to respond to prednisolone

(spleen is the dominant site of RBC (spleen is the dominant site of RBC destruction )destruction )

Immunosuppressive therapyImmunosuppressive therapy in those who fail to respond to prednisolone in those who fail to respond to prednisolone

and splenectomyand splenectomy Cyclophosphamide 100mg/day.Cyclophosphamide 100mg/day. Azathioprine 150mg/day.Azathioprine 150mg/day. Rituximab 375mg/m2/week.Rituximab 375mg/m2/week.

Intravenous gamma globulin therapy.Intravenous gamma globulin therapy. May cause rapid cessation of hemolysis.May cause rapid cessation of hemolysis.

(not as effective as in immune thrombo (not as effective as in immune thrombo

cytopenia-ITP)cytopenia-ITP)

Blood transfusionBlood transfusion if severe anemia.if severe anemia. Warm antibody in IHA is a Panagglutinin.Warm antibody in IHA is a Panagglutinin. This antibody reacts with all normal donor This antibody reacts with all normal donor

cells and hence compatible crossmatching is cells and hence compatible crossmatching is impossible. impossible.

Remove the autoantibody from patients serum Remove the autoantibody from patients serum and then test for the presence of alloantibody and then test for the presence of alloantibody to donor blood groups.to donor blood groups.

PrognosisPrognosis AIHA is transient in children following viral AIHA is transient in children following viral

infection.infection. Usually chronic in adults with exacerbations Usually chronic in adults with exacerbations

and remissionsand remissions

Warm AIHAWarm AIHA

COLD ANTIBODY COLD ANTIBODY IMMUNOHEMOLYTIC ANEMIA.IMMUNOHEMOLYTIC ANEMIA.

These antibodies are usually IgM and bind to red These antibodies are usually IgM and bind to red cells best at 4cells best at 4ooC and thus agglutinate RBC and C and thus agglutinate RBC and are called cold agglutinins.are called cold agglutinins.

Uncommonly the antibody is IgG Uncommonly the antibody is IgG (Donath-Landsteiner antibody of paroxysmal (Donath-Landsteiner antibody of paroxysmal cold hemoglobinuria)cold hemoglobinuria)

Cold reacting autoantibodiesCold reacting autoantibodies Are of 2 typesAre of 2 types

Monoclonal Monoclonal Polyclonal.Polyclonal.

MonoclonalMonoclonal these antibodies are the product of these antibodies are the product of

lymphoproliferative disorders lymphoproliferative disorders Also seen in idiopathic cold hemagglutinin Also seen in idiopathic cold hemagglutinin

syndrome.syndrome.

Polyclonal antibodiesPolyclonal antibodies seen in response to infection as in seen in response to infection as in

Mycoplasma Pneumonia Mycoplasma Pneumonia Infectious mononucleosis.Infectious mononucleosis.

The antibodies attach to red cells mainly in The antibodies attach to red cells mainly in the peripheral circulation where the blood the peripheral circulation where the blood temperature is cooled.temperature is cooled.

IgM antibodies are highly efficient at fixing IgM antibodies are highly efficient at fixing complement and both intra and complement and both intra and extravascular hemolysis can occur.extravascular hemolysis can occur.

Cold agglutinins reacting against the I Cold agglutinins reacting against the I antigen on the red cell surface are called antigen on the red cell surface are called anti I.anti I.

These antibodies are seen in These antibodies are seen in Mycoplasma infections Mycoplasma infections Benign lymphoproliferative disorders.Benign lymphoproliferative disorders.

Anti i antibodies react with fetal blood and Anti i antibodies react with fetal blood and are seen in are seen in Aggressive lymphomas Aggressive lymphomas Infectious mononucleosis.Infectious mononucleosis.

CLINICAL FEATURES.CLINICAL FEATURES.

Acrocyanosis.Acrocyanosis. Hemolysis.Hemolysis. AcrocyanosisAcrocyanosis

marked purpling of the extremities,ears and nose marked purpling of the extremities,ears and nose when the blood becomes cold enough to agglutinate when the blood becomes cold enough to agglutinate in the veins.in the veins.

Clears on warming and does not have Clears on warming and does not have vasospastic features.vasospastic features.

Symptoms may be present when swallowing Symptoms may be present when swallowing cold foods or drinks.cold foods or drinks.

HemolysisHemolysis usually not severe with mild reticulocytosis usually not severe with mild reticulocytosis

and agglutination on the blood film. and agglutination on the blood film. occurs primarily due to the hemolytic action of occurs primarily due to the hemolytic action of

the complement as there are no functional Fc the complement as there are no functional Fc receptors for the IgM antobody on the receptors for the IgM antobody on the phagocytes.phagocytes.

Severe hemolysis occurs only with massive Severe hemolysis occurs only with massive activation of the antibody(eg.,sudden cooling)activation of the antibody(eg.,sudden cooling)

The activation of the complement is marked The activation of the complement is marked by accumulation of a degradation product of by accumulation of a degradation product of C3 called C3dg on the RBC surface which is C3 called C3dg on the RBC surface which is detected with appropriate antisera(anti-C3) in detected with appropriate antisera(anti-C3) in the direct coombs test.the direct coombs test.

COLD AIHACOLD AIHA

PAROXYSMAL PAROXYSMAL COLD HEMOGLOBINURIACOLD HEMOGLOBINURIA

Rare syndrome of intravascular hemolysis Rare syndrome of intravascular hemolysis after exposure to cold.after exposure to cold.

Results from the formation of the Donath Results from the formation of the Donath Landsteiner antibody an IgG antibody Landsteiner antibody an IgG antibody directed against the P blood group antigen directed against the P blood group antigen and that can induce complement mediated and that can induce complement mediated lysis.lysis.

Attacks are precipated on exposure to cold Attacks are precipated on exposure to cold and assoc with hemoglobinemia, and assoc with hemoglobinemia, hemoglobinuria, chills and fever, back, leg hemoglobinuria, chills and fever, back, leg and abdominal pain, headache and and abdominal pain, headache and malaise.malaise.

TREATMENT.TREATMENT.

Maintain patient in warm environment.Maintain patient in warm environment. Splenectomy not of value.Splenectomy not of value. Prednisolone of limited value.Prednisolone of limited value. Chlorambucil and cyclophoshamide for Chlorambucil and cyclophoshamide for

patients having hemollysis assoc with patients having hemollysis assoc with monoclonal gammopathy.monoclonal gammopathy.

Rituximab(anti CD20)Rituximab(anti CD20) Successful treatment of the neoplasm Successful treatment of the neoplasm

responsible for the cold agglutinin.responsible for the cold agglutinin.

Recovery from acute episode is prompt.Recovery from acute episode is prompt. Asymptomatic between episodes.Asymptomatic between episodes. PCH usually secondary to a viral infection PCH usually secondary to a viral infection

or are autoimmune.or are autoimmune. PCH used to be more frequent with tertiary PCH used to be more frequent with tertiary

syphilis.syphilis. Following a viral infection (measles, Following a viral infection (measles,

mumps) it is self limited but maybe severe.mumps) it is self limited but maybe severe.

Direct coombs test may show complement Direct coombs test may show complement (seldom IgG) but may be negative.(seldom IgG) but may be negative.

Diagnosis made by demonstrating cold Diagnosis made by demonstrating cold reacting IgG antibodies or by special reacting IgG antibodies or by special antiglobulin tests.antiglobulin tests.

Chronic auto immune PCH may respond Chronic auto immune PCH may respond to prednisolone or cytotoxic therapy to prednisolone or cytotoxic therapy (azathioprine or cyclophosphamide)(azathioprine or cyclophosphamide)

Natural history of PCH extends over many Natural history of PCH extends over many years.years.

COLD ANTIBODY COLD ANTIBODY IMMUNOHEMOLYTC ANEMIAIMMUNOHEMOLYTC ANEMIA

Cold agglutinin disease:Cold agglutinin disease: AcuteAcute

mycoplasma infectionmycoplasma infection infectious mononucleosisinfectious mononucleosis

ChronicChronic IdiopathicIdiopathic lymphoma.lymphoma.

Paroxysmal cold hemoglobinuria.Paroxysmal cold hemoglobinuria. Ulcerative colitis.Ulcerative colitis.

Transient Cold agglutinins occur commonly with Transient Cold agglutinins occur commonly with mycoplasma pneumoniae infection and mycoplasma pneumoniae infection and infectious mononucleosis infectious mononucleosis

In both, the titer of antibody is too low to cause In both, the titer of antibody is too low to cause clinical symptoms of hemolysis ( antibody titer in clinical symptoms of hemolysis ( antibody titer in symptomatic patients is usually about 1:2000 or symptomatic patients is usually about 1:2000 or more dilution)more dilution)

Only rarely there is hemolysis Only rarely there is hemolysis The presence of cold agglutinins is of diagnostic The presence of cold agglutinins is of diagnostic

value value

ALLOIMMUNE (ISOIMMUNE) ALLOIMMUNE (ISOIMMUNE) HEMOLYTIC ANEMIASHEMOLYTIC ANEMIAS

In these hemolytic anemia's, the antibody In these hemolytic anemia's, the antibody produced by one individual reacts with red produced by one individual reacts with red cells of anothercells of another

CausesCauses ABO incompatibilityABO incompatibility

• Transfusion of incompatible blood results in Transfusion of incompatible blood results in massive intravascular hemolysis and the blood film massive intravascular hemolysis and the blood film usually shows both autoagglutination and usually shows both autoagglutination and spherocytosis.spherocytosis.

Hemolytic disease of the newbornHemolytic disease of the newborn Due to Rh incompatibility of the materno fetal Due to Rh incompatibility of the materno fetal

blood groups.blood groups.

The increased use of allogenic transplantation The increased use of allogenic transplantation for renal, hepatic, cardiac and bone marrow for renal, hepatic, cardiac and bone marrow diseases has led to the recognition of diseases has led to the recognition of alloimmune hemolytic anemia resulting from alloimmune hemolytic anemia resulting from the production of red cell antibodies in the the production of red cell antibodies in the recipient by donor lymphocytes transferred in recipient by donor lymphocytes transferred in the allograft.the allograft.

DRUG INDUCED DRUG INDUCED IMMUNOHEMOLYTIC ANEMIAIMMUNOHEMOLYTIC ANEMIA

Drugs cause IHA by 2 different Drugs cause IHA by 2 different mechanisms:mechanisms: by inducing a disorder similar to warm by inducing a disorder similar to warm

antibody IHA(eg.,methyl dopa)antibody IHA(eg.,methyl dopa) by becoming associated as haptens with RBC by becoming associated as haptens with RBC

surface and induce the formation of an surface and induce the formation of an antibody against RBC-drug antibody against RBC-drug complex(eg.,penicillin, quinidine)complex(eg.,penicillin, quinidine)

With methyl dopa:With methyl dopa: 10% of patients taking 2g/day usually show a 10% of patients taking 2g/day usually show a

positive direct coombs test.positive direct coombs test. Few may show spherocytosis and hemolysis.Few may show spherocytosis and hemolysis. The autoantibodies crossreact with Rh The autoantibodies crossreact with Rh

protein.protein. The autoantibody may persist for many The autoantibody may persist for many

months after the drug is discontinued.months after the drug is discontinued.

The hemolytic reaction continues until the The hemolytic reaction continues until the drug has been discontinued.drug has been discontinued.

Penicillin and its congeners cause this type of Penicillin and its congeners cause this type of reaction when given in high doses(10 million reaction when given in high doses(10 million units/day or more)units/day or more)

The direct coombs test is positive only with The direct coombs test is positive only with anti IgG.anti IgG.

The indirect coombs test is positive only when The indirect coombs test is positive only when the normal RBCs are coated with penicillinthe normal RBCs are coated with penicillin

Complement is not usually fixed.Complement is not usually fixed. Hemolysis is usually not severe.Hemolysis is usually not severe. As the antibody is of IgG type,spherocytosis As the antibody is of IgG type,spherocytosis

and splenic destruction may occur.and splenic destruction may occur. Other drugs like quinine,quinidine, Other drugs like quinine,quinidine,

sulfonamides, sulfonylureas, phenacetin etc sulfonamides, sulfonylureas, phenacetin etc do not adhere tightly to the RBC surface and do not adhere tightly to the RBC surface and the drug antibody complexes are removed the drug antibody complexes are removed during the washing steps of the coombs during the washing steps of the coombs reactions.reactions.

These IgM antibodies are able to fix complement These IgM antibodies are able to fix complement and C3d and C4d remain on the RBC surface.and C3d and C4d remain on the RBC surface.

Therefore the direct coombs test is positive with Therefore the direct coombs test is positive with anti C3 but not with anti IgG.anti C3 but not with anti IgG.

The antibody is detected in the indirect coombs The antibody is detected in the indirect coombs test only when the drug is added to the test only when the drug is added to the incubation mixture.incubation mixture.

Hemolysis may be severe and resolves once the Hemolysis may be severe and resolves once the drug is discontinued.drug is discontinued.

PowerPoint* Lecture slide Presentation By

Dr.P.L.John Israel , Professor & Head of the Department of Internal Medicine

Prathima Institute of Medical Sciences, Nagunur-Karimnagar Dist.

Andhra Pradesh - INDIA