Haemolysis

Question 1

Classification of haemolysis by site

Answer 1

Extravascular

Intravascular

Question 2

Test results indicative of haemolysis (6)

Answer 2

Low Hb
Unconjugated hyperbilirubinaemia
Increased serum LDH
Reticulocytosis
Spherocytes (extravascular)
Schistocytes (intravascular)

Question 3

Reasons why spleen may be enlarged in haemolysis (2)

Answer 3

Volume of red cells being phagocytosed in spleen

Extramedullary haemopoiesis

Question 4

Parvovirus infection in haemolytic patients can lead to…

Answer 4

Red cell aplasia

Question 5

Hereditary spherocytosis (HS) results from…

Answer 5

mutations in genes linking the red cell membrane to the cytoskeleton

Question 6

Inheritance of HS

Answer 6

Usually autosomal dominant

Question 7

Complications of chronic haemolysis in HS (3)

Answer 7

Gallstones/biliary obstruction
Aplastic crises
Megaloblastic anaemia due to folate deficiency (3)

Question 8

Diagnostic test for HS

Answer 8

Osmotic fragility test (RBCs show increased fragility in hypotonic solution)

Question 9

Management of HS (2)

Answer 9

Folate replacement

Splenectomy

Question 10

Genetic cause of G6PD deficiency

Answer 10

X-linked recessive mutations in G6PD

Question 11

How does G6PD deficiency cause haemolysis?

Answer 11

Makes the red cells vulnerable to oxidative stress

Question 12

Blood film results in G6PD deficiency (2)

Answer 12

Heinz bodies- red cell inclusions due to haemoglobin denaturation
“Bite cells”

Question 13

Precipitants of crisis in G6PD deficiency (4)

Answer 13

Broad beans (favism)
Infections
Antimalarials
“Sulfa” drugs

Question 14

Diagnostic test for G6PD

Answer 14

G6PD enzyme assay

Question 15

Management of G6PD

Answer 15

Avoidance of precipitants

Question 16

Inherited causes of haemolysis (3)

Answer 16

Hereditary spherocytosis
Sickle cell anaemia
G6PD deficiency

Question 17

Classification of acquired haemolysis

Answer 17

Immune and non-immune

Question 18

Types of autoimmune haemolytic anaemias (3)

Answer 18

Warm-reactive
Cold-reactive
Paroxysmal

Question 19

Which type of autoimmune haemolytic anaemia responds to changes in ambient temperature?

Answer 19

Cold-reactive

Question 20

Diagnostic test for autoimmune haemolytic anaemias

Answer 20

Direct antiglobulin test (Coomb’s test)

Question 21

Describe how Coomb’s test works

Answer 21

Blood sample from patient with antibodies attached to red cells is incubated with anti-Ig antibodies- causes agglutination

Question 22

Examples of situations where alloimmune haemolytic anaemia might arise (2)

Answer 22

Acute transfusion reaction

Haemolytic disease of the newborn

Question 23

Causes of non-immune acquired haemolytic anaemia (5)

Answer 23

MAHA (causes include HUS, DIC)
Burns
Infections e.g. malaria
Hypersplenism
Drugs/chemicals e.g. lead, copper