Hemolytic Anemias DDDDDDAIHA 2024 EU.ppt

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1. Hemolytic Anemia
Professor
Ahmed kaidSalem
29/02/2024

2. Physiological Hemolysis
•RBC’s normally survive ̰120 days .
•After this period RBC’swill be recognized as (old)
senescent cells by reticuloendothelialsystem
cells (RES)and will be removed from the
circulation and destroyed, liberating :
•Globin chains, will be reused as amino acids.
•Hemwill be destroyed into Iron (Fe) which will
be reused in body functions and porpherin
indirect bilirubinconjugated bilirubin (oxidation
by microflorain small intestine) into
sterchobilinogen(stool) and urobilinogen(urine). Dr Ahmed kaidSalem

3. Dr Ahmed kaidSalem

4. Normal Hemolysis
Is the destruction or
removal of the old red
blood cells from the
circulation after their
normal lifespan of 120
days.
Dr Ahmed kaidSalem

7. Abnormal Hemolysis
Is the destruction or
removal of red blood cells
from the circulation before
their normal lifespan of
120 days.
Dr Ahmed kaidSalem

8. Hemolytic Anemias(HA)
•A group of anemiascaused by reduction
in red blood cell life span < 120 days.
•RBC’s normally survive 120 days .
•Bone marrow(BM)has the capacity to
increase erythropoiesis6-8 times.
•HAis thepremature destruction of
RBCs exceeding the erythropoietic
capacity of the bone marrow.
Dr Ahmed kaidSalem

9. •The common denominator in HAs is
an increase in RBCs destruction.
•Increased BM activitymay compensate
temporay for this destruction.
•Failure to increase the production of
RBCs, anemia develops.
•Anemia may not be seen until the red
cell lifespan is lessthan 30 days.
Physiopathology of HA
Dr Ahmed kaidSalem

10. Classificationof Hemolytic
Anemias(HAs)
HAscanbe classified in several ways:
1-According to the Site of haemolysis:
•Extravascular haemolytic anemia
•Intravascular haemolytic anemia
2-According to the Site of the defect in RBCs:
•Intrinsic defect(intracorpuscular) (intracellular)
•Extrinsic defect(extracorpuscular)(extracellular)
3-According to the cause of the disease
•Inherited and AcquiredDr Ahmed kaidSalem

11. Extravascular hemolysis
•Red cell
destruction
usually occurs
in the cells of
the RES.
Dr Ahmed kaidSalem

12. Intravascular hemolysis
•Destruction
of red cells
occurs inside
the blood
vessels.
Dr Ahmed kaidSalem

13. Comparison between Extravascular
and Intravascular Hemolysis
NoCharacteristicsExtravascular Intravascular
1Site of hemolysisRES(spleen, marrow)In circulation
2SplenomegalyUsually present Uncommon
3Indirect bilirubinRaised Mildly raised
4Haptoglobin Normal Decreased
5HemoglobinemiaNot seen Positive
6HemoglobinureaAbsent Present
7HemosiderinureaAbsent Present
8Example Thalassemia,SCA PNH, G6PD

14. Classification of HAs
According to the cause of hemolysis:
•Inherited HAare caused by intrinsic defect.
•Acquired HAare caused by extrinsic defect
•There are some exceptions:
•Paroxysmal nocturnal haemoglobinuria
(PNH)Which is an acquired intrinsic defect
•Hereditary G6PD enzyme deficiency no
hemolysis unless there is extrinsic factor
Dr Ahmed kaid Salem

15. Acquired HA
•Immune
1.Autoimmune (Autoimmune Hemolytic Anemia)
2.Allo-immune ( Hemolytic Disease of Newborn,
Hemolytic Transfusion Reactions)
•Red cell fragmentation syndromes
–March hemoglobinuria
–Infections, Chemical and physical agents.
–Paroxysmal Nocturnal Hemoglobinuria
–DIC, HUS and TTP
Dr Ahmed kaidSalem

16. Inherited Hemolytic A
•Membrane defects:(hereditary
spherocytosis)
•Metabolic defect (G6PD
enzyme deficiency): Favism.
•Haemoglobin defects: (sickle
cell disease or thalassemia).
Dr Ahmed kaidSalem

17. Clinical Manifestation/ HAs
•Onsetmaybeacuteorinsidious
•Symptomsandsignsofanemia
•Jaundice/Withoutpruritus
•Symptomsandsignsspecifictothe
typeofhemolyticanemia
•Symptomsandsignsrelatedtothe
underlyingdisease
Dr Ahmed kaidSalem

18. Clinical Manifestations/HAs
•Splenomegaly(some types )
•Cholelithiasis(gall bladder stones)symptoms
•Leg ulcers (sickle cellanemia, spherocytosis)
•Skeletal abnormalities (thalassemia& sickle CA)
•Changes in urine color(tea color urine)
•Crises (in chronic hemolytic disease)
–Aplastic crises (Parvo-virus-B19)
–Hemolyticcrises
–Megaloblasticcrises
Dr Ahmed kaidSalem

19. Laboratory findingsin HA are
related to the followings:
I-Increased RBC Intravascular destruction:
2-Increased RBC Extravascular destruction:
3-Increased RBC production
Dr Ahmed kaidSalem

20. Laboratory findingsof
extravascular hemolysis
1.Increased unconjugated bilirubin
2.Increased CO production.
3.Increased urobilinogen excretion
4.Increased serum LDH
Dr Ahmed kaidSalem

22. Laboratory findingsof
intravascularhemolysis
1.Hemoglobinemia
2.Hemoglobinuria
3.Hemosiderinuria
4.Absence/decreasehaptoglobin
5.Methemalbuminemia
Dr Ahmed kaidSalem

23. Laboratory findingsof
increased RBC production
1.Leucocytosis
2.Thrombocytosis
3.Reticulocytosis
4.Presence of nucleated RBCs in the
peripheral blood
5.Hypercelullarity of bone marrow
Dr Ahmed kaidSalem

24. Morphologic abnormalities in
hemolytic anemias
Polychromasia
Spherocyte
Sickle cell
Target cels
Schistocytes
Agglutination
Increased reticulocytescount
HereditarySpherocytosis,Immune
hemolytic anemia
Sickle cell anemia
Thalassemia, HbC disease, liver
disease
MAHA, uremia, DIC, hypertesion,
eclampsia, vasculitis or
malignancy Dr Ahmed kaidSalem

25. Dr Ahmed kaidSalem

26. Special Laboratory tests
•Coombs antiglobulin test-Immune hemolysis
•Osmotic fragility test–H. spherocytosis
•Red cell sicklingtest -sickle cell anemia
•Hemoglobin electrophoresis -Thalassemias
and sickle cell anemia
•Red cell enzyme assays-G6PDdeficiency
•Oxygen dissociation curve-
Hemoglobinopathy High oxygen affinity Hb
Dr Ahmed kaidSalem

31. Dr Ahmed kaidSalem

32. Dr Ahmed kaidSalem

33. Dr Ahmed kaidSalem

34. Dr Ahmed kaidSalem

35. Dr Ahmed kaidSalem

36. Autoimmune
Hemolytic Anemia
(AIHA)
Professor Ahmed kaid Salem
29.02.2024

37. Autoimmune hemolytic
anemia(AIHA)
•AIHA is characterized by
1.Shortened Red Blood Cells survival
2.Failure of compensatory mechanism of BM
2. Presence of autoantibodies directed against
autologous Red Blood Cells.
3. A positive direct antiglobulintest (DAT) Coombs’test.
•80% patients with AIHA exhibit warm-reactive
autoantibodies of IgGisotypeon their red cells.
•20% exhibit cold-reactive autoantibodies.

38. •Two types of cold-reactive autoantibodiesto
Red Blood Cells are recognized:
1.Cold agglutinins are IgMisotype
2.Cold hemolysinsare of IgGisotype.
•The DAT may detect IgG, fragments of
complement ( C3), or both on the RBCs of
patients with warm-antibody AHA.
•In cold-antibody AIHA, only complement is
detected.
Autoimmune hemolytic anemia-
cold-reactive autoantibodies

42. I. Warm-Autoantibody Type: 80%
•Autoantibody Maximal Active at Body Temperature 37°C
A. Primary or idiopathic warm AHA
B. Secondary warm AHA
1.Associated with lymphoproliferativedisorders
2.Associated with the rheumatic disorders (SLE)
3.Associated with certain neoplasms(ovarian tumors)
4.Associated with chronic inflammatory diseases
(ulcerative colitis)
5.Associated with ingestion of certain drugs (methyldopa)
Classification of Autoimmune
Hemolytic Anemia

43. II. Cold-Autoantibody Type: 20%
Autoantibody Optimally Active at Temperatures <37°C (4°C )
A. Mediated by cold agglutinins
1.Idiopathic (primary) chronic cold agglutinin disease.
2.Secondary cold agglutinin hemolytic anemia
a. Postinfectious(M. pneumoniaeor infectious mononucleosis)
b. Associated with malignant B-cell lymphoproliferativedisorder
B. Mediated by cold hemolysins
1.Idiopathic (primary) paroxysmal cold hemoglobinuria
2.Secondary a. Donath-Landsteiner hemolytic an,
associated with acute viral syndrome in children
b. Congenital or tertiary syphilis in adults
Classification of AIHA

44. III. Mixed Cold and Warm antibodies
•A. Primary or idiopathic mixed AIHA
•B. Secondary mixed AIHA
IV. Drug-Induced AIHA
A. Haptenor drug adsorption
B. Ternary (immune) complex
C. True autoantibody mechanism
Classification of AIHA

45. Warm-reacting antibodies
AIHA
•Due to development of an IgGantibody
•Antibody active at warm temperature of( 37°C)
•Primary (Idiopathic)
•Secondary-due to an underlying disease
1.Lymphoproliferative disorders
2.Autoimmune diseases
3.Infections
4.Immunodeficiency disorder
5.Tumors

46. Epidemiology-Warm AIHA
•Incidence of 1-3 cases per 100,000/ year
•Females: male ratio 2:1
•Age at occurrence depend on the cause.
•Primary more common in women.
•Secondary occurs in association with
underlying disease

47. Mechanism of destruction of
Warm-reacting antibodies AIHA
•Destructionis extravascular hemolysis.
•Antibodies bind to the surface of RBC
membrane, Fc portion of antibody binds
to macrophages, Interaction → small
RBCs (spherocytes).
•Spherocytes become rigid and trapped
in spleen and are destroyed

51. Cold-agglutinin disease
•Due to development of an IgMantibody
•Antibody active at cold temperature (4°C)
•Primary (idiopathic)
•Secondary-due to an underlying disease
1.Lymphoproliferative disorders
2.Infections
3.Immunodeficiency disorder
4.Autoimmune diseases 5. Tumors

52. Epidemiology-Cold
agglutinin Disease
•Is less common, with a prevalence of
14 cases /million /year.
•Accounts for 16-32% of AIHA
•Affects older adults around 70 year
•Slight female predilection

53. Effectors mechanisms for
immune red cell destruction
Two main effector mechanisms exist
in vivo :
•(i) Cell -mediated, predominantly
extravascular, immune destruction
•(ii) Complement -mediated
intravascular hemolysis

55. Mechanism of destruction in
cold-reacting antibodies-AIHA
•Intravascular hemolysis
•IgM antibodies fixed on RBC, activate
the compliment system resulting in
cytolysis in the circulation.
•Extravascular hemolysis C3b:occurs in
the liver via action of Kupffer cells.

56. Auto-antibody characteristics
•Antibodies may be:
•Autoantibodies:produced by the patient’s
own immune system and directed against
his/her own red cell antigens.
•Alloantibodiesare produced by the patient’s
immune system and directed against foreign red
blood cell antigens byblood transfusion.
•Alloantibodies:directed against the patient ’ s red
cell antigens introduced to the patient, from the
mother in hemolytic disease of the newborn.

57. Clinical Features
Onset is acute, with rapidly
developing anemia with risk of
heart failure.
Severe cases can occur with
fulminating hemolysis, resulting
in life -threatening anemia.

58. •Symptoms of anemia
•Pallor
•Mild jaundice (tinge)
•Dark urine
•Mild splenomegaly
Clinical Features

59. •Polychromasia(Reticulocytosis)
1.Spherocytes
2.Macrocyts
3.Circulating nucleated red cells
4.Red cell agglutination.
Peripheral blood film examination

60. Biochemistry
•Increased unconjugated serum bilirubin
•Increased urinary urobilinogen
•Increased lactate dehydrogenase (LDH)
•The DAT is positive, of RBC coated with
IgG alone or IgG and complement

61. Warm –type AIHA-Treatment
1. Corticosteroids
First -line treatment of warm AIHA is with
corticosteroids.
•The initial dose should be prednisolone 1 –2
mg/kg daily.
•The dose should be continued for 10 -14 day
2. Folic acid supplements

62. 3.Cytotoxic immunosuppressive d rugs
1. Azathioprine: dose of 1.5 –2.0 mg/kg/d
2. Cyclophosphamide1.5 –2.0 mg/kg/d
3. Ciclosporin, starting at 5 mg/kg/d
4. Mycophenolatemofetil
4. Intravenous immunoglobulins(IgG)
5. Splenectomy
6. Monoclonal antibody therapy-Rituximab
Warm-type AIHA-Treatment

63. Blood transfusion
Blood transfusion must be given if the
clinical situation demands it:
1.Hemoglobin continues to fall
2.Heart failure develops
There is impossibility of achieving a
satisfactory cross -matching in the presence
of a Positive Direct AntiglobinTest (DAT)
•The least incompatible blood should be
transfused slowly.

64. Cold –type AIHA
•The clinical features of the cold
hemagglutinin syndromes vary
with the pathogenesis of the
underlying disorder.
•Primary is uncommon disorder
accounting for only 15% of AIHA

65. Idiopathic cold haemagglutinin
disease -Clinical features
•Is mainly seen in older people and
runs a chronic course.
•Purplish skin discoloration, maximal
over the extremities (acrocyanosis).
•Acrocyanosis:is stasis in the
peripheral circulation secondary to
RBC agglutination.

66. Idiopathic cold haemagglutinin
disease -Clinical features
•Anemia is usually present
•Patient may be mild icteric
•Spontaneous agglutination of red
cells is observed, both
macroscopically and on blood film
if made at room temperature
•The DAT shows C3d on the RBC.

69. Idiopathic cold haemagglutinin
disease -Treatment
Management of cold haemagglutinin
syndromes :
•Avoidance of exposure to cold
•Electrically heated gloves and socks.
•The patient should be nursed in a
warm environment, at 37 °C.

70. Idiopathic cold haemagglutinin
disease -Treatment
•Folic acid supplements.
•Alkylating agents-Chlorambucil
•Corticosteroids -are of no use.
•Splenectomy -is of no use.
•Anti -CD20 monoclonal
antibody (Rituximab)

71. Idiopathic cold hemagglutinin
disease -Treatment
•Blood transfusion
Blood transfusions should be given in spite of the
difficulty in cross -matching in the presence of
cold hemagglutinins, if the patient is in heart
failure only.
•Blood should be given through an blood warmer.
•Plasma e xchange (plasmapheresis)
The titre of cold agglutinin may be lowered temporarily by
plasma exchange.

72. Paroxysmal cold hemoglobinuria
•Rare syndrome usually occurs in children
following acute viral infections.
•Described by Donath-Landsteiner in syphilis.
•Presentation is with sudden intravascular
haemolysis resulting in:
•Pallor and Dark urine (haemoglobinuria)
•Abdominal pain
•Sometimes collapse.

73. Paroxysmal cold haemoglobinuria
•The cold autoantibody is a biphasic
IgG (Donath –Landsteiner
antibody) that reacts with red cells
below 20°C in the peripheral
circulation, causing lysis by
complement activation as the red
cells are warmed to 37°C in the
central circulation & large vessels.

74. Treatment of Paroxysmal
Hemoglobinuria
•Treatment depends on keeping
the patient warm.
•Transfusion of ABO and rhesus -
compatible blood should be
given through a blood warmer.

75. Lab General Features-of AIHA
•Low hemoglobin and high bilirubin.
•Increased reticulocyte count-Polychromasia.
•Spherocytosis.
•Positive DAT.
•Neutropenia/neutrophilia.
•Thrombocytosis/thrombocytopenia.
•AIHA+ITP =Evan’s syndrome

80. Lab General Features-of
AIHA
•RBC fragments
•Nucleated RBCs
•Erythrophagocytosis by monocytes
•Patient with cold-antibody AIHA may exhibit
RBC autoagglutinationin the blood
film and in chilled anticoagulated blood .
•Marrow exam reveals erythroid hyperplasia

81. Laboratory Features-of AIHA
•Total serum bilirubin is increased.
•Unconjugated hyperbilirubinemia is increased
•Urinary urobilinogen is increased
•Serum haptoglobin levels are low
•Lactate dehydrogenase levels are elevated.
•Hemoglobinuria in patients with:
–Cold agglutinin disease
–Paroxysmal cold hemoglobinuria
–Drug-immune hemolytic anemia

85. Differential Diagnosis
•Several non autoimmune diseases may result
in spherocytic anemia:
•Hereditary spherocytosis (HS)
•Clostridial sepsis
•Hemolytic anemia preceding Wilson disease.
•Drug-immune hemolytic anemia
•Recently received a transfusion
•Recent allogeneic transplantation.

86. Warm-reactingAIHA Cold -reactingAIHA
React at 37°C Reactat room tempera
Insidious to acute Chronic
Severe anemia Less severe anemia
Fever and jaundice Fever and jaundice
Extravascular Intravascular
NOAutoagglutinationAutoagglutination
Urobilinogen Hemoglobinuria
NO Acrocyanosis Acrocyanosis
Organomegaly NO Organomegaly
Responseto steroidsNO Responseto steroids