Haemolytic anaemia Flashcards Preview

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Flashcards in Haemolytic anaemia Deck (28):
1

What is the normal red cell life span?

120 days

2

  1. What is haemolysis?
  2. What are the two types?

1. Haemolysis is defined as shortended red cell survival. May be predominantly:

  • Intravascular - within circulation
  • Extravascular - remova;/destructio by reticuloendothelial system

2. Inherited for acquired 

3

What are the 3 main causes of extravascular haemolytic anemia?

  • Autoimmune
  • Alloimmune
  • Hereditary spherocytosis

4

What are some of the causes of intravascular haemolytic anaemia?

  • Malaria
  • G6PD deficiency
  • Mismatched blood transfusion
  • Cold antibody haemolytic syndromes
  • Drugs
  • Microangiopathic haemolytic anaemia (MAHA) e.g. HUS
  • Thrombotic thrombocytopenic purpura
  • Paroxysmal nocturnal haemoglobinuria 

5

What form of inheritance is hereditary spherocytosis?

Autosomal dominant 

6

What are the consequences of having haemolytic anaemia?

  • Anaemia
  • Erythroid hyperplasia with increased rate of red cell production and circulating reticulocytes
  • Increased folate demand
  • Susceptibility to effect of Parvovirus B19 (slap cheek)
  • Propensity to gallstones
  • Increased risk of iron overload and osteoporosis

7

What other syndrome when coinherited further increase risk of gallstones in chronic haemolytic anaemia?

Gilbert syndrome

UGT 1A1 TA7/TA7 genotype

8

What are the clinical features of chronic haemolytic anemia?

  • Pallor
  • Jaundice
  • Splenomegaly
  • Pigmenturia
  • Family history

9

What are the possible laboratory findings in people with chronic haemolytic anemia?

  • Anaemia
  • Increased reticulocytes
  • Polychromasia
  • Hyperbilirubinaemia
  • Increased LDH
  • Reduced/absent haptoglobins
  • Haemoglobinuria
  • Haemosiderinuria - brown urine and a side effect of chronic intravascular haemolytic anemia

10

What are the two main red cell membrane disorders that can cause haemolytic anemia?

  • Hereditary spherocytosis
  • Hereditary elliptocytosis

11

What are the red cell membrane disorders in hereditary spherocytosis?

  • Vertical interaction
  • Band 3, protein 4.2, Ankyrin and/or Beta spectrin 

12

What are the red cell membrane defects in hereditary elliptocytosis?

  • Horizontal interaction
  • Alpha spectrin
  • Beta spectrin
  • Protein 4.1

13

  1. What is hereditary spherocytosis?
  2. What is the mode of inheritance?

  1. Genetic defect of red cell cytoskeleton
  2. Autosomal dominant - 75% of cases 

Red cells have an increased risk of lysis - osmotic fragility test

Reduced binding of dye eosin-5-maleimide 

14

What does this image show?

Q image thumb

Hereditary spherocytosis

15

What does this image show?

Q image thumb

Hereditary elliptocytosis

16

What does this image show?

Q image thumb

Hereditary pyropoikilocytosis 

irregularly shaped cells - an autsomal recessive disorder

17

  1. What is G6PD-deficiency (inc. full name)?
  2. How do people develop it?
  3. What are the clinical effects?

1. Glucose-6-phosphate dehydrogenase deficiency. G6PD is an enzyme that catalyzes the first step in the pentose phosphate pathway, that leads to the generation of NADPH which is required to maintain intracellular glutathione (GSH)

2. X linked inheritance, seen in hemizygous males and homozygous females

3. Clinical effects include 

  • Neonatal jaundice
  • Acute hemolysis (triggered by oxidants/infection)
  • Chronic hemolytic anemia (rare)

18

What can cause acute hemolysis in people with G6PD deficiency?

Usually asymptomatic

However, drugs, infections or fava beans can cause acute hemolysis in people with G6PD deficiency

19

What does this image show?

Q image thumb

G6PD deficiency blood film 

20

What does this blood film show? (features)

Q image thumb

Heinz bodies, stained with methylviolet

Sign of intravascular hemolysis and of G6PD deficiency

21

Name some common agents that provoke G6PD deficiency

  • Anti-malarials
  • Antibiotics - sulphonamides, ciprofloxacin
  • Vitamin K
  • Fava beans
  • Moth balls

There are more!

22

What does this image show?

Q image thumb

Pyruvate kinase deficiency (post-splenectomy)

 

23

What does this image show?

Q image thumb

Pyrimidine 5'-nucleotidase deficiency

24

What are the first line investigations if G6PD deficiency is suspected?

  • Direct antiglobulin test (DAT) or Coombs test - hemolytic anemia
  • Urinary haemosiderin/haemoglobin
  • Osmotic fragility
  • G6PD +/- PK activity
  • Haemoglobin seperation A and F%
  • Heinz body stain
  • Ham's test/Flow cytometry of GPI-linked proteins
  • Thick and thin blood film 

25

What are the principles of management for G6PD deficiency?

 

  • Folic acid supplementation
  • Avoidance of precipitating factors e.g. oxidants in G6PD deficiency
  • Red cell transfusion/exchange
  • Immunisation against blood borne viruses e.g. Hep A and B
  • Monitor for chronic complications
  • Cholecystectomy for symptomatic gallstones
  • Splenectomy if indicated

26

What are the indications for a splenectomy?

Substantial benefit in:

  • PK deficiency and some other enzymeopathies
  • Hereditary spherocytosis
  • Severe elliptocytosis/pyropoikilocytosis
  • Thalassaemia syndromes
  • Immune haemolytic anemia

27

What is one of the main risks for people who have a splenectomy?

  • Risk of overwhelming sepsis by capsulated bacteria e.g. Pneumococcus 
  • Penicillin prophylaxis and immunisation 

28

What are the indications for a splenectomy?

  1. Criteria?
  2. Age?

1. Criteria

  • Transfusion dependence
  • Growth delay
  • Physical limitation Hb < 8g/dl
  • Hypersplenism

2. Not before teh age of 3 years but before 10 years to maximise pubertal growth