HAEMOLYTIC ANAEMIA

Dr Maryam Jameelah AizuddinDr Siti Nurzafira

PRESENTATION OUTLINE

Definition

Types of haemolytic disorders

Haemoglobinopathy

Enzymopathy

Membranopathy

Extrinsic Factors

Immune Haemolytic Anemia

Presentation (signs and symptoms)

Pathophysiology

Investigations

Management

HAEMOLYTIC ANAEMIA:DEFINITIONS

Haemolysis: Premature destruction of RBCs.Anaemia results => destructions exceed capacity of BM to produce RBCsNormal RBCs survival time => 110-120 days

NORMAL BLOOD FILM

Normal peripheral blood smear showing RBCs. The RBCs are uniform in size, and the central areas of pallor are slightly less than half the total diameter of an RBC. The four dark objects (arrows) outside the RBCs are platelets. 

(From Hoffbrand AV: Color Atlas: Clinical Hematology, 3rd ed. St. Louis, Mosby, 2000, p 22, Fig. 1-62.)

HAEMOLYTIC ANAEMIA:CLINICAL FEATURESJaundice: generally mild and often not noticed by the patient.

Anaemia: Recent onset = acquired Long-standing = possibly congenital.

Haemoglobinuria: intravascular haemolysis.Urobilinogenuria: increased Hb catabolism.

Splenic pain: spenomegaly or splenic infarction.

Leg ulcers: intrinsic red cell disorders, e.g. sickle cell disease.

WHAT HAPPENED DURING HAEMOLYIS?

RBCs survival shorthened => RBCs

EPO (stimulation in BM to RBCs)

=> Reticulocytosis (2-3)

(Ddx: acute blood loss, vit B 12 or folate deficiency)

HAEMOLYTIC ANAEMIA:LABORATORY FINDINGS

Features of increased erythrocyte breakdown:

Unconjugated bilirubinaemia.

Urobilinogenuria.

Haptoglobins decreased.

Features of increased erythrocyte production:

Reticulocytosis Polychromasia and nucleated

red cells in peripheral blood film. Erythroid hyperplasia in bone

marrow aspirate. Radiological changes, e.g. "hair

on end" appearance of cranial X-ray.

The ‘hair’ represents the accentuated trabeculae extending between the inner and outer skull tables in the expanded diploic marrow spaces. It appears to be ‘on end’ because the trabeculae are oriented perpendicular to the inner and outer tables of the skull. The term is now classically associated with the radiographic changes seen in hemolitic anemia. A. Sickle cell disease. B. Thalassemia.

Features specific to intravascular haemolysis:

• Haemoglobinaemia(haptoglobin and haemopexin

exhausted).• Methaemoglobinaemia.• Haemoglobinuria.• Haemosiderinuria.

CLASSIFICATION OF HAEMOLYTIC ANAEMIA

Cellular Defect

• Enzyme deficiencies (G6PD deficiency, Pyruvate kinase deiciency

• Haemoglobin defects• Membrane defects (hereditary

spherocytes)

Extracellula

r defects

• Autoimmune Haemolytic anaemia (warm and cold antibosy)

• Isoimmune Haemolytic anaemia

CELLULAR DEFECT:HEREDITARY SPEROCYTOSIS The most common inherited abnormality of RBCs membrane

Prevalence ~1 in 5000 people of Nothern European decsent but has been described in most ethnics group

Others:Hereditary elliptocytosisUsually no anemiaAutosomal dominant, affecting 1/2500 Europeans

Hereditary pyropoikilocytosis

CELLULAR DEFECT:HEREDITARY SPEROCYTOSIS Autosomal Dominant trait

Patients develop hemolysis and abdominal pain with even trivial infectious illnesses

Defect is in proteins of the membrane skeleton, usually spectrin or ankyrin

Lipid microvesicles are pinched off in the spleen and other RE organs, causing decreased MCV and spherocytic change.

CELLULAR DEFECT:HEREDITARY SPEROCYTOSIS

Normal

Abnormal-HS cells lyse more readily at low ionic strength

Diagnosed by Osmotic Fragility

CELLULAR DEFECT:HEREDITARY SPEROCYTOSISBLOOD FILM

Peripheral blood with spherocytes in hereditary spherocytosis. Numerous, round, dense red blood cells without central areas of pallor represent spherocytes (arrows). The mean corpuscular hemoglobin concentration is increased. 

(From Damjanov I, Linder J: Pathology: A Color Atlas. St. Louis, Mosby, 2000, p 75, Fig. 5-7.)

HEREDITARY SPHEROCYTOSISHOW DO WE TREAT?

None : if Hb > 10g/dL and reticulocytes counts 10% Transfusion : if severe anaemia, poor growth, aplastic crises and age <2 years Folic acid

CELLULAR DEFECTS:G6PD DEFICIENCY

CELLULAR DEFECT: G6PD DEFICIENCYPATHOPHYSIOLOGY

G6PD activity results in NADPH and

glutathione, which are required to protect hemoglobin from oxidative damage.

Oxidizing agents converts hemoglobin to methemoglobin, then denature it, causing it to precipitate as Heinz bodies.

The spleen pinches off the Heinz body and the overlying membrane, leaving a “bite cell” or “blister cell”

GLUCOSE 6-PHOSPHATE DEHYDROGENASE

FUNCTIONS Regenerates NADPH, allowing regeneration of glutathione

Protects against oxidative stress

Lack of G6PD leads to hemolysis during oxidative stress Infection Medications Fava beans

G6PD DEFICIENCYCLINICAL FEATURES

Typically, hemolysis is triggered by drugs or infections. Anemia is maximal 7-10 d after exposure. Urine becomes dark associated with low back & abd pain Wait for 6 wk after hemolysis to do enzyme assay

HEINZ BODY HAEMOLYTIC ANAEMIA

G6PD deficiency is the most common enzymopathy causing hereditary haemolytic anaemia.Bite cells and helmet cells

Blister cell

Heinz bodies

Peripheral blood smear with a bite cell and inset showing Heinz bodies in glucose-6-phosphate dehydrogenase deficiency. The arrowshows a bite cell with part of the red blood cell membrane removed. The inset shows a peripheral blood smear with a supravital stain visualizing punctate inclusions representing denatured hemoglobin (Heinz bodies). 

(From Kumar V, Fausto N, Abbas A: Robbins and Cotran's Pathologic Basis of Disease, 7th ed. Philadelphia, WB Saunders, 2004, Fig. 13-8; inset from Wickramasinghe SN, McCullough J: Blood and Bone Marrow Pathology. London, Churchill Livingstone, 2003, Fig. 8-8.)

G6PD DEFICIENCY AGENTS TO AVOID

–Primaquine

–Aspirin

–Quinolones(cipro)

–Sulfa drugs

–Dapsone

–Fava beans(favism)

–Naphtha compounds (mothballs)

G6PD DEFICIENT: TREATMENT

Avoid oxidant drugs

Transfuse in severe cases

IV fluids to maintain good urine output

Splenectomy in severe recurrent hemolysis

Folic acid supplements

WHY 5 DAYS OF OBSERVATION?

The bilirubin levels usually are the highest during day 3-5 of life

INHERITANCE OF G6PD DEFICIENT IN FEMALE? G6PD is an x linked enzyme deficiency

Usually affected males

How female are affected?

Lyon Hypothesis : in Heterozygous female may have G6PD when there is random inactivation of normal X chromosome.

Most affected female do not have clinical hemolysis after exposure of oxidant drug

PYRUVATE KINASE DEFICIENCY

Pyruvate kinase catalyzes the phosphorylation of ADP to ATP with the formation of pyruvate. Pyruvate then reduces any NADH present to NAD with formation of lactate. Loss of florescence of NADH under ultra-violet light is observed as evidence of the presence of pyruvate kinase.

phosphoenol pyruvate

pyruvate

lactate

PK

ADP ATP *NADH NAD

PYRUVATE KINASE DEFICIENCY:CLINICAL MANIFESTATIONS In new born

Severe jaundice, kernicterus

Anaemic symptoms

Older children

Hb ranging 8-12g/dL, some pallor, jaundice,

splenomegaly (usually doesn’t need Tx)

Relative high incidence among the Amish

Peripheral blood smear in pyruvate kinase deficiency. The arrow shows one of many red blood cells with thorny projections (echinocytes) extending from the red blood cell membrane. (From Wickramasinghe SN, McCullough J: Blood and Bone Marrow Pathology. London, Churchill Livingstone, 2003, Fig. 8-10.)

PYRUVATE KINASE DEFICIENCY: THE AMISH

Autosomal recessive trait The amish - Intermarriage

PYRUVATE KINASE DEFICIENCY: DIAGNOSIS Demonstration of marked reduction in RBC PK activity Increase Michaeli-Menten dissociation constant (Km) for phophoenolpyruvate

Peripheral blood smear in pyruvate kinase deficiency. The arrow shows one of many red blood cells with thorny projections (echinocytes) extending from the red blood cell membrane. 

(From Wickramasinghe SN, McCullough J: Blood and Bone Marrow Pathology. London, Churchill Livingstone, 2003, Fig. 8-10.)

PYRUVATE KINASE DEFICIENCY:TREATMENTS Exchange transfusion maybe indicated for hyperbilirubinaemia in newborn

Transfusion of PCs for severe anaemia or aplastic crises

Splenectomy after age of 5-6 years old

Structural Hemoglobin Defects

Hemoglobin SHemoglobin C

Thalassemias

Alpha thalassemiaBeta thalassemia

Haemoglobin Defect

SICKLE CELL DISEASE Characterized by severe anemia generalized growth and developmental impairment

SCD is characterized by its presentation: Vaso-occlusive crises Sequestration crises Hemolytic crises Aplasic crises

Dx: clinical findings peripheral blood smear hemoglobin analysis

SCD is characterized by its presentation:

1- Vaso-occlusive crises2- Sequestration crises3- Hemolytic crises4- Aplasic crises

Crewcut appearance

Pathophysiology of sickle cell anemia

EXTRACELLULAR:AIHA ASSOCIATED WITH “WARM” ANTIBODY Hallmark of this disease => + direct (Coombs Test) detects coating of Ig/complements on RBCs

Antibodies are active at 35-40 oC

Most often belong to IgG class

Do not require complement for its activity

Usually do not produce agglutination in vitro

Etilology:

Abnormal Ig directed against RBCs but mechanism not clearly understood

Molecular mimicry

Infectious agents – results RBCs membrane antigenic

Primary/ idiopathic type

Secondary – associated with SLE/ immunodeficiency

CLINICAL MANIFESTATIONS Acute transient

Lasting 3-6 month

Predominant in children age 2-12 yr

Often preceded by infection usually respiratory

Pallor, jaundice, pyrexia, haemoglobinuria, fatigue

Spleen usually enlarged

Consistent response to glucocorticoids therapy

Chronic

May lasts from months to years

Frequent in infants and children older than 12yr

Response to glucocorticoids variable and inconsistent

LABORATORY FINDINGS

Profound anaemia Hb < 6g/dL

High retics

Leucocytosis common

High LDH

Platlet usually normal but concomitant ITP sometimes occur

Direct Coombs => POSITIVE

Indirect Coombs sometimes can be positive (free antibody in the serum)

BLOOD FILM

Spherocytes and polychromasia

Polychromasia. The arrow depicts a blue discolored red blood cell without a central area of pallor. (From Naeim F: Atlas of Bone Marrow and Blood Pathology. Philadelphia, WB Saunders, 2001, Fig. 1-15A.)

TREATMENT

Transfusion may be required initially (May be EXTREMELY difficult to find compatible blood: blood in which RBCS give least positive in vitro reaction by Coombs technique)

Mild disease may not require any treatment

More severe disease => Prednisolone 2-6mg/kg/day ( rate of haemolysis by blocking macrophages, production of autoantibody)

Tx should be continued until haemolysis rate , gradually tappering down dose)

If haemolytic anaemia still remains => higher dose of glucocorticoids , IViG maybe tried , Rituximab

Refractory case => plasmapheresis

Splenectomy may be beneficial

AIHA ASSOCIATED WITH COLD ANTIBODIES Cold antibodies => RBCs antibodies more active at T and agglutinates RBCs at T <37oC

Primarily IgM and require complements for activity

Primary/Idiopathic

Secondary to infection Mycoplasma pneumoniae, EBV

Secondary to lymphoproliferative disorder

LABORATORY FINDINGS

Haemoglobinaemia

Haemoglobinurea

Spontaneous RBCs agglutination => RBCs agglutination seen in blood film

MCV

Red blood cell agglutination in a patient with a cold (IgM) immune hemolytic anemia. (Courtesy of Jean Schafer.)

TREATMENT

Self limiting

? transfusion

Glucocorticoids much less effective

Patient should avoid exposure to cold (warm blood products, fluids)

Treat for underlying disease

Rarely, in severe haemolytic anaemia => immunosuppression and plasmapheresis

Steroids and splenectomy are usually ineffective

EXTRACELLULAR:ISOIMMUNE HAEMOLYTIC ANAEMIAHAEMOLYTIC DISEASE OF THE NEWBORN(ERYTHROBLASTOSIS FETALIS)

Transpacental passage of maternal Ig active against paternal RBC antigens of infant

=> RBCs destruction

ABO INHERITANCE

RH INCOMPATIBILITY

Rh antigenic => genetically transmitted by each parents

Pathogenesis:

Rh negative mother

Rh positive infant’s blood (D antigen) infused into mother’s system

Ig formation against D antigen occur in unsensitised Rh negative mother

Once senstisation has occurred => small dose of antigen Ig titre

Initially IgM antibody, later takes place by IgG=> readily cross placenta

WHY DOES IT RARELY OCCUR DURING FIRST PREGNANCY? Transfusion occur near to time of delivery => too late for mother to become sensitized and trasmit Ig

Ability of mother to produce antibody => produce only low titre

CLINICAL MANIFESTATION Laboratory evidence of mild haemolysis (15%)

Severe anaemia with compensatory hyperplasia or erythropoetic tissue => hepatosplenomegaly

Anaemic S&S => when compensatory capacity of haemopoetic system is exceeded

Profound anaemia (pallor, signs of cardiac decompensation)

Massive anasarca

Hydrops fetalis

Jaundice first day of life => massive haemolysis

(Risk of bilirubin enchephalopathy/ kenicterus)

DIAGNOSISANTENATAL DX:For Rh negative mother: Hx of previous transfusion, abortion, pregnancy => possible sensitisation, prev affected infant, stillbirth

parents blood types should be tested => incompatibility

Maternal titre Ig towards D antigens=> 12-26 wk, 28-32wk and 38 wk

Monitoring severity of fetal disease=> TAS (evidence of hydrops fetalis), doppler US( evidence of increase vascular resistance in middle cerebral artery), amniocentesis/ cordocentesis??, PUBS is the goal standard

DIAGNOSIS:POSTNATAL Definitive: demonstration of blood group incompatibilty and corresponding Ig bound to infant’s RBCs, Rh type

Anaemia (in hydrop fetalis may be as low as 3-4g/dL)

WCC may be normal or elevated

Thrombocytopenia in severe cases

Serum bilirubin

Retics increase

Direct coombs test : POSITIVE

Blood film : polychromasia and marked increase in nucleated RBCs

TREATMENT

Unborn infant: Hydrops fetal anaemia (Hct 30%) => intravascular fetal transfusion

Liveborn infant: Fresh, low-titre, group O, leucoreduced and irradiated Rh-neg blood should be available

Evidence of hydrops fetalis

immediate resuscitation, supportive treatment, haemodynamic stabilisation before proceeding with ET

ET => previous kernicterus, retic >15%, prematurity

Monitoring => FBC and serum bilirubin 4-6 hr interval

PREVENTION OF RH SENSITISATION RhoGAM (human anti D globulin)

IM 300 microgramwithin 72 hrs of delivery of Rh postive infant, ectopic pregnancy, abdominal trauma in pregnancy, abortion

RhoGAm also more effective if administered at 28-32 week than again at birth than given as a single dose

BLOOD GROUP A AND B INCOMPATIBILITY Most common cause of incompatibility

15% of birth are at risk, manifestation 0.3-2.2%

IgM antibodies do not cross placenta, but mother who have develop IgM antibody towards A/B from previous sensitisation => haemolytic anameia

Presentation (milder than Rh incompatibility)

Treatment: phototherapy or rarely ET (post discharge, monitoring of Hg/Hct is essential)