Lecture 4: Red cells, Haemoglobin, and Introduction to anaemia

Question 1

What is hereditary spherocytosis?

Answer 1

An abnormality in spectrin in membrane of RBC reducing life span
Cells look like spheres

Question 2

a defective production of globin chains is?

Answer 2

Thalassaemia

Question 3

Deficiency in iron results in?

Answer 3

reduced production of haem resulting in low Hb

Question 4

HIF1-a and HIF1-B role in response to hypoxia?

Answer 4

• EpoR –> erythropoesis
• TfR –> supply of iron
• VEGF –> angiogenesis
• Glycolytic enzymes supply of energy

Question 5

What happens to HIF1-a in high O2?

Answer 5

Ubiquitination –> degredation via proteasome

Question 6

What are the changes with development of mature RBC from proerthroblast

Answer 6

• progressive increase in haemoglobin
• chromatin clumping
• extrude nucleus
• loss of a RNA

Question 7

What are the kinetics of erythropoiesis?

Answer 7

• 4 cells cycles/division (1–>16)
• process takes 7-10 days
• Reticulocyte stage takes 2 days

Question 8

average RBC life span?

Answer 8

120 days

Question 9

Where is EPO produced and when is it released?

Answer 9

• Kidney

- released in low O2

Question 10

Effects of EPO?

Answer 10

• stimulation of BFU-E and CFU-E
• increased haemoglobin synthesis
• Reduced RBC maturation time
• increased reticulocyte release
• results in increased haemoglobin
• therefore increased oxygen delivery

Question 11

Initial catagorization of anemia?

Answer 11

• Hemolytic
• Hypoproliferative
• Ineffective

Question 12

How do reticulocyte counts change in anemic patients?

Answer 12

• Should be raised due to hypoxia –> EPO

- If not raised then indicates that issue is with the bone marrow or EPO synthesis

Question 13

Factors that impair the normal reticulocyte respone?

Answer 13

• Iron, folate or B12 deficiency
• Lack of EPO
• Ineffective erythropoiesis as in thalassemia and myelodysplastic syndromes
• chronic inflammation or malignancy