Haemolytic anaemia Flashcards Preview

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Flashcards in Haemolytic anaemia Deck (15):
1

Definition 

  • anaemia related to reduced RBC lifespan
  • no blood loss 
  • no haematinic defiency 

BONE MARROW IS NORMAL 

2

Role of Bm in compensating for haemolytic anaemia 

  • 120 days - HB normal 
  • 20-100d - Hb normal , reticulocytes increases, bilirubin increased( increased cell breakdown, unconjgated not seen in urine) Bone marrow compensates 
  • <20d - Hb decreased, reticulocytes up, bilirubin up, spleen up 

3

Classification of haemolytic anaemia 

Congenital 

  • abnormalities of RBC membrane (hereditary spherocytosis)
  • abnormalities of haemoglobin
  • Enzyme defects- G6PD defiencies  

4

Hereditary spherocytosis 

 

  • autosomal dominant -like most structural defects 
  • RBCs spherocytic and polychromatic (increased reticulocytes)
  • jaundice 
  • splenomegaly 
  • treatment if required - splenectomy 

5

Risk of removing a spleen 

rise from encapsulated organisms pneumococcus, meningococcus, haemophillus 

immunusation and long term penicillin 

6

Types of RBC enzyme defects 

  • Pyruvate kinase defiiency anaemia 
  •  

7

Pyruvate kinase defieincy anaemia 

  • chronic extravascular haemolysis 
  • ATP depletion 
  • Autosomal recessive 
  • defiency of pyruvate kinase enzyme 
  • large amounts of 23DPG (acts to shift oxygen dissociation to the right, facilitates transfer of oxygen to tissues) 
  • patients still have good oxygen supply 

8

Glucose 6 phosphate dehydrogenase defieincy 

  • acute episodic intravascular haemolysis 
  • x-linked recessive
  • acute haemolysis from oxidative stress 
    • favism 
    • drugs (antimalarias, sulphonamides)

9

Acquired haemolytic anaemia can be 

  • Immune 
    • autoimmune (warm or cold) 
    • drug induced 
    • issoimmune- haemolytic disease of the newborn 
  • non-immune 
    • trauma 
    • infection (malaria, speticaemia) 

10

Cold AIHA 

  • autoantigoby IgM
  • "in the Middle of winter its cold IgM
  • causes 
    • mycoplasma infection 
    • idiopathic
  • Red cell agglutinations 

 

11

Warm AIHA

  • autoantibody IgG
  • Causes 
    • idiopathic -30%
    • other autoimmne disease 
    • lymphoproliferative disorder 
    • drug induced 
  • blood film - Spehorocytic and polychromatic 

 

 

12

Drug indeced AIHA 

  1. Hapten
    • drug can attach as a hapten to 
    • Red cell and hapten raise antibodies 
    • Abs attack hapten/rbc complex 
    • mild haemolytic state 
  2. Immune complex (innocent bystander)
    • drug is present 
    • antibodies raised to it 
    • Antibodies fix and complement and move across 
    • Attach to the RBCs causing intravascular haemolysis 
    • Severe haemolyssi - cephalopsorins!

13

Direct coombs test 

 Warm AIH 

  • purpose test to detect warm IgG on RBC surface 
  • Direct coombs test! 
  • Add antbodies to IgG 
  • cause an immune lattic to form 
  • causing red cell agglutination 

 

14

Indirect coombs test 

Cold AIH 

  • Uses patients plasma (antibodies) + 1 unit of blood that has bee crossmatched with the patient 
  • Sample of RED cell from unit of blood + sample of patients plasma into test tube 
  • if patients plasma contains ABs they will stick tot eh red cells 
  • Add antibodies to antibdies 
  • agglunitation forms 
  • Are there unexpected red cell antibodies!!! 

 

15

Treatment of COLD and WARM haemolytic anaemia 

  • Cold 
    • Mycoplasma - self limiting 
    • idiopathic- keep warm (antibodies stick to RBCS in cold areas) 
  • Warm 
    • stop any drugs 
    • steroids 
    • immunosuppresion - azathioprine 
    • splenectomy - if fails