Flashcards in Haemolysis Deck (18)
What is haemolysis?
Premature red cell destruction
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
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
What are some of the possible consequences of haemolysis?
Excess red cell breakdown products e.g bilirubin
What are some of the possible causes of intravascular haemolysis?
Abnormal blood products are spilled directly into the circulation
ABO incompatible blood transfusion
Severe falciparum malaria (blackwater fever)
PNH and PCH
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)
What is the problem in extravascular haemolysis?
Normal products are in excess
Where does extravascular haemolysis mostly affect?
The reticuloendothelial system
(liver and spleen)
How does extravascular haemolysis present?
Hyperplasia at the site of destruction (hepatomegaly and splenomegaly)
Jaundice and gall stones (unconjugated bilirubinaemia)
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
What is the difference between autoimmune and alloimmune haemolysis?
Autoimmune haemolysis = own antibodies
Alloimmune haemolysis = passive transfer of antibodies
What are some of the possible causes of alloimmune haemolysis?
Haemolytic transfusion reaction
Haemolytic disease of the newborn
What are some of the mechanical causes of haemolysis?
Disseminated intravascular coagulation
Haemolytic uraemic syndrome
Leaking heart valve
What are some of the causes of abnormal cell membrane which can cause haemolysis?
Vitamin E deficiency
Paroxysmal nocturnal haemoglobinuria
Name a cause of abnormal red cell metabolism which can lead to haemolysis
Name a cause of abnormal haemoglobin which can cause haemolysis
Sickle cell disease (HbS)
What investigations can be done for haemolysis?
Serum unconjugated bilirubin