lecture 14 - haemolytic anaemias & haemoglobinopathies Flashcards
What is the haematological function of the spleen?
To filter out old and defective red blood cells
What are the components of the splenic filter?
Cords, sinuses, macrophages
What is the function of the macrophages in the splenic cords?
They engulf dead/dying red blood cells
When red cells are lysed in the spleen, what binds to the Hb released?
Haptoglobin
What are haemolytic anaemias?
When red cells have reduced red cell survival in the circulation
What oxidises haemoglobin after haemolysis?
Nitric Oxide (NO)
Why can severe haemolysis cause thrombosis?
Haemolysis releases Hb which is oxidised by nitric oxide (NO). NO is required for vasodilation, which prevents thrombus formation.
What is the product of the breakdown of haem?
Bilirubin
How is unconjugated bilirubin carried in the blood?
Bound to albumin
Why do haemolytic anaemias often lead to macrocytic anaemia?
Because haemolysis will trigger increased red cell production, causing the release of lots of large, immature reticulocytes.
What is the most common red cell enzymopathy which causes haemolysis?
G6PD deficiency
What is Sickle Cell anaemia?
Mutation of globin change resulting in HbS
