Flashcards in Haemolysis Deck (17)
What is haemolysis?
Premature red cell breakdown
Why are red cells particularly susceptible to damage?
Limited metabolic reserve; rely on glycolysis
Can't generate new protein once circulating
What is meant by compensated haemolysis?
Increased red cell destruction followed by increased red cell production
i.e. Hb is maintained
What is decompensated haemolysis, AKA haemolytic anaemia?
Increased red cell destruction exceeding level of red cell production
i.e. Hb not maintained
What are the consequences of haemolysis?
Erythroid hyperplasia (increased bone marrow RBC turnover)
Excess RBC breakdown products (bilirubin)
What are the 2 bone marrow responses to haemolysis?
Reticulocytes in the circulation are diagnostic of haemolysis. True/False?
Can be present in bleeding, iron therapy, anaemia etc.
What are the 2 classifications of haemolysis that make it easier for us to identify the cause?
Extravascular (more common)
What does extravascular haemolysis involve?
Hyperplasia at site of destruction
Release of protoporphyrin, resulting in unconjugated jaundice
i.e. normal blood products in excess
What does intravascular haemolysis involve?
Red cells destroyed in the circulation and spill contents
i.e. abnormal products
What are the 4 main features/products of intravascular haemolysis?
Haemoglobinaemia (free Hb in blood)
Haemoglobinuria (pink urine turns black)
What investigations are done to confirm haemolytic state?
FBC + blood film
Serum unconj. bilirubin
What might be seen on a blood film in haemolysis when identifying a cause?
Membrane damage (spherocytes)
Mechanical damage (red cell fragments)
Oxidative damage (Heinz bodies)
What is the direct Coomb's test used for?
Identifies antibody (and Complement) bound to red cells
Acute haemolytic transfusion reaction involves Ig? antibody and is usually an intravascular/extravascular haemolysis
Acute haemolytic transfusion reaction involves IgM antibody and is usually an intravascular haemolysis
Delayed haemolytic transfusion reaction involves Ig? antibody and is usually an intravascular/extravascular haemolysis
Delayed haemolytic transfusion reaction involves IgG antibody and is usually an extravascular haemolysis