Red blood cell production and survival

Question 1

What is the first recognisable RBC in blood?

Answer 1

• proerythroblast is first recognisable RBC precursor in marrow

Question 2

What are the features of a proerythroblast?

Answer 2

Proerythroblast is the first recognizable cell in the erythroid series. It is a large cell with loose, lacy chromatin and clearly visible nucleoli; its cytoplasm is basophilic.

Question 3

Describe basophilic erythroblast

Answer 3

The next stage is represented by the basophilic erythroblast, with a strongly basophilic cytoplasm and a condensed nucleus that has no visible nucleolus. The basophilia is caused by the large number of polyribosomes involved in the synthesis of haemoglobin.

Question 4

Describe how we the body increases RBC count

Answer 4

On image

Question 5

What else besides EPO?

Answer 5

• Iron
• Vit B12
• Folate
• Erythroid precursors

Question 6

What foods are a good source of iron?

Answer 6

meat, eggs, vegetables, dairy foods

Question 7

Describe the absorption of iron (4)

Answer 7

• Normal Western diet provides 15mg daily.
• 5-10% absorbed (1mg) principally in duodenum and jejunum.
• gastric secretion (HCl) and ascorbic acid help absorption.
• DMT-1 and ferroportin regulate
• Iron absorption is regulated by DMT-1 and ferroportin;

Question 8

What are the causes of iron deficiency

Answer 8

Decreased uptake, Increase demand and increase loss and explain pregnancy relation to iron

Question 9

What happens when we have an iron deficiency?

Answer 9

on image

Question 10

vitamin B12 and Folic Acid

Answer 10

• Both essential for RBC maturation & DNA synthesis
• Both needed for formation of thymidine triphosphate.
• B12 is coenzyme for methionine synthase in methylation of homocysteine to methionine.
• Deficiency in either of them causes abnormal & diminished DNA, leading to failure of nuclear maturation.

Question 11

What are the three classifications of Haemolytic Anaemia

Answer 11

Hereditary/Congenital vs Acquired

Extravascular vs Intravascular

Intrinsic vs Extrinsic

Question 12

What causes acquired Haemolytic Anaemia?

Answer 12

Autoimmune
Alloimmune
Drug-induced

Red Cell fragmentation
Infection:
Secondary

Question 13

What causes hereditary Haemolytic Anaemia?

Answer 13

Red Cell membrane disorders
Hereditary spherocytosis and hereditary elliptocytosis

Red Cell enzymopathies
G6PD deficiency
PK deficiency

Haemoglobinopathies
Sickle cell diseases
thalassaemias

Question 14

What happens in G6PD deficiency?

Answer 14

NADPH and GSH generation impaired

Acute haemolysis on exposure to oxidant stress: oxidative drugs, fava beans (broad beans) or infections

Hb precipitation – Heinz bodies

G6PD deficiency most common known enzymopathy, estimated to affect 400 million people worldwide.

…….but have evolutionary benefit

Question 15

What happens in PK deficiency

Answer 15

ATP is depleted:

cells lose large amount of potassium & water, becoming dehydrated & rigid.

because cation pumps fail to function.

causes chronic non-spherocytic haemolytic anaemia

excess haemolysis leads to jaundice, gallstones