Week 231 - Anaemia: Flashcards
Week 231 - Anaemia: What are the causes of microcytic anaemia?
- Thalassaemia
- Iron Deficiency
- Anaemia of chronic disease
Week 231 - Anaemia: What does Ferritin represent?
Intracellular iron stores, but it also an acute phase protein.
Week 231 - Anaemia: What are the broad causes of iron deficiency?
- Poor intake
- Reduced absorption
- Increased losses
- Increased demand
Week 231 - Anaemia: What can cause reduced absorption of iron?
- Abnormal bowel - Crohns, Coeliac, Gastritis.
- Lack of Bowel - Bypass, resection.
- Interference - PPIs, Calcium supplements, Thalins, Chocolate
Week 231 - Anaemia: What can cause increased losses of iron?
- Menstruation
- Occult blood loss
- Haemolysis
- Haemodialysis
Week 231 - Anaemia: What is the life span of an erythrocyte?
120 days
Week 231 - Anaemia: Outline Erythropoiesis.
1) Erythropoietin (EPO) is synthesized primarily from the renal cortex.
2) EPO stimulates stem cells within the bone marrow to differentiate into erythroid precursors.
3) EPO continues to stimulate primitive erythroid cells in the bone marrow and induce maturation.
4) Macrophages surround these cells in the bone marrow to become erythroblastic islands.
Week 231 - Anaemia: Production of erythropoietin is triggered by what?
Tissue hypoxia (Oxygen tension within the tubules of the kidney)
Week 231 - Anaemia: How does chronic renal disease cause anaemia and what is the morphology of it?
The production of EPO is reduced as this takes place in the renal cortex. There is therefore a reduction in red blood cell production.
- The cells will be normocytic.
Week 231 - Anaemia: What is the cell line of erythropoiesis?
1) Marrow
2) Pronormoblast
3) Normoblast
4) Reticulocytes
5) Erythrocytes
Week 231 - Anaemia: What is a reticulocyte? Why are they important?
- ‘Teenager’ of erythropoiesis.
- Raised following haemorrhage, haemolytic anaemia.
- They provide an excellent measure of red cell production and the age of the red cell population.
Week 231 - Anaemia: Why does iron deficiency lead to microcytic anaemia?
- Iron is the rate limiting step of erythropoiesis.
* Without adequate iron, the cells will divided more leading to a reduced size.
Week 231 - Anaemia: Why does B12 and folate deficiency lead to a macrocytic anaemia?
- These are key building blocks for DNA synthesis and cell mitoses.
- Inadequate amounts of B12 and folate lead to less divisions resulting in erythrocytes being pumped into blood at a larger size.
Week 231 - Anaemia: What would the iron profile be in someone with iron deficiency? (Serum iron, TIBC, Ferritin, Serum soluble transferrin receptors)
- Serum Iron - Reduced
- TIBC (total iron-binding capacity) - Increase since the body works hard to bind any free iron.
- Ferritin - Reduced
- Serum soluble transferrin receptors - Increased
Week 231 - Anaemia: How is vitamin B12 absorbed?
- Stomach - B12 binds with intrinsic factor to form a complex.
- Terminal ileum - Travels through the small intestine where it is absorbed in the terminal ileum.