haemolytic anaemia Flashcards
1
Q
What is the main cause of inherited extravascular haemolysis?
A
-Hereditary Spherocytosis
2
Q
Describe the pathogenesis of hereditary spherocytosis
A
- A defect in the proteins involved with interactions between the cytoskeleton and lipid bilayer of the red cell causes ineffective membrane formation (e.g Ankyrin deficiency)
- Red cells are produced normally by the bone marrow but lose membrane - The loss of membrane causes a decrease in the surface area to volume ratio, leading to spherical shaped red cells.
- Sphereocytes are not able to pass though microcirculation, especially the spleen.
- As a result, the spherocytes die prematurely
3
Q
- Splenomegaly, Low Hb, Low MCV. Reticulocyte count 16%
- Blood film: Spherocytosis
- Most likely diagnosis?
A
-Hereditary spherocytosis
4
Q
How is hereditary spherocytosis treated?
A
- Splenectomy
- Folic acid in severe cases
5
Q
-Describe the pathogenesis of Hereditary Elliptocytosis
A
- It is usually caused by the failure of spectrin heterodimers to self-associate into heterotetramers.
- Causing cell rigidity and increased tendency to lyse
6
Q
Splenomegaly, Low Hb, Low MCV. Reticulocyte count 16%
- Blood film: Elliptocytes - Most likely diagnosis?
A
-Hereditary Elliptocytosis
7
Q
-What metabolic pathway does pyruvate kinase deficiency affect?
A
The Embden-Meyerhof pathway
8
Q
What are the consequences of inherited haemolytic anaemias?
A
Anaemia
- Erythroid hyperplasia: increased red cell production and reticulocytes - Increased folate demand - Susceptibility to the effect of parvovirus B19 - Increased risk of: gallstones, Iron overload, Osteoporosis
9
Q
What is the difference between intravascular and extravascular haemolysis?
A
- Extravascular haemolysis describes when red cells are excessively removed by the RE system (Reticuloendothelial system/Macrophage system).
- Intravascular haemolysis describes when red cells are broken down directly within the circulation
