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Flashcards in Haemolysis Deck (18)
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1

What is haemolysis?

Premature red cell destruction

2

Why are red cells so susceptible to damage?

Need to have a biconcave shape

Rely on glycolysis - no mitochondria

Can't replicate or repair damage - no nucleus

3

What is compensated and decompensated haemolysis?

Increased red cell destruction compensated by increased red cell production

Decompensated haemolysis is when there is increased red cell destruction which exceeds bone marrow capacity for production

4

What are some of the possible consequences of haemolysis?

Reticulocytosis

Erythroid hyperplasia

Excess red cell breakdown products e.g bilirubin

5

What are some of the possible causes of intravascular haemolysis?

Abnormal blood products are spilled directly into the circulation

ABO incompatible blood transfusion

G6PD deficiency

Severe falciparum malaria (blackwater fever)

PNH and PCH

6

What are some of the clinical features of intravascular haemolysis?

Haemoglobinaemia (Free Hb in the circulation)

Methaemalbuminaemia (Hb bound to albumin)

Haemoglobinuria (pink urine - turns black when left to stand)

Haemosiderinuria (brown urine)

7

What is the problem in extravascular haemolysis?

Normal products are in excess

8

Where does extravascular haemolysis mostly affect?

The reticuloendothelial system

(liver and spleen)

9

How does extravascular haemolysis present?

Hyperplasia at the site of destruction (hepatomegaly and splenomegaly)

Jaundice and gall stones (unconjugated bilirubinaemia)

10

Autoimmune causes of haemolysis can be split into warm or cold autoantibody. Which antibodies are involved and which is most common

Warm = IgG - most common

Cold = IgM

11

What is the difference between autoimmune and alloimmune haemolysis?

Autoimmune haemolysis = own antibodies

Alloimmune haemolysis = passive transfer of antibodies

12

What are some of the possible causes of alloimmune haemolysis?

Haemolytic transfusion reaction

Haemolytic disease of the newborn

ABO incompatibility

13

What are some of the mechanical causes of haemolysis?

Disseminated intravascular coagulation

Haemolytic uraemic syndrome

Leaking heart valve

Infections

Burns

14

What are some of the causes of abnormal cell membrane which can cause haemolysis?

Hereditary spherocytosis

Liver disease

Vitamin E deficiency

Paroxysmal nocturnal haemoglobinuria

15

Name a cause of abnormal red cell metabolism which can lead to haemolysis

G6PD deficiency

16

Name a cause of abnormal haemoglobin which can cause haemolysis

Sickle cell disease (HbS)

17

What investigations can be done for haemolysis?

FBCs
Blood film
Reticulocyte count
Serum unconjugated bilirubin
Serum haptoglobin
Urinary urobilinogen
Coomb's test

18

What is the function of Coomb's test?

Identifies antibodies and complements bound to own red cells

A positive test involves agglutination