Red blood cells

Question 1

What is anaemia?

Answer 1

Reduction in red cell count or haemoglobin content of red cell count

Question 2

What are general aetiologies to anaemia?

Answer 2

Bloof loss
Decreased production
Defective production
Increased destruction

Question 3

What is a reticulocyte?

Answer 3

Immature red blood cell - not fully haemoglobinised

Question 4

What metals are required for blood production?

Answer 4

Iron
Copper
Cobalt
Manganese

Question 5

What vitamins are required for red cell production?

Answer 5

B12 
Folic acid
Thiamine
B6
C
E

Question 6

What hormones are required to produce red cells?

Answer 6

Erythropoietin
GM-CSF
Androgens
Thyroxine

Question 7

What is a normal red cell lifespan?

Answer 7

120 days

Question 8

Where does red cell breakdown occur?

Answer 8

Spleen

Question 9

What are red cells broken down to?

Answer 9

Globin - amino acids

Haem - iron - recycled into haemoglobin, haem - billirubin

Question 10

What happens to billirubin after red cell breakdown?

Answer 10

Binds to albumin in the plasma

Question 11

Where can genetic effects cause congenital anaemia?

Answer 11

Red cell membrane
Metabolic pathways - enzymes
In haemoglobin

Question 12

What maintains the shape of red cells?

Answer 12

Skeletal proteins in the membrane

Question 13

What is the commonest red cell membrane disorder?

Answer 13

Hereditary spherocytosis

Question 14

Is hereditary spherocytosis autosomal dominant or recessive?

Answer 14

Dominant

Question 15

What is clinical presentation of congenital anaemias?

Answer 15

Anaemia
Jaundice (neonatal)
Spenomegaly
Pigment gallstones

Question 16

How do we treat hereditary spherocytosis?

Answer 16

Folic acid
Transfusion
Spenectomy if severe anaemia

Question 17

What are rarer membrane disorders?

Answer 17

Hereditary elliptocytosis
Hereditary pyropoikilocytosis
South east asian ovalocytosis

Question 18

What pathways are important in red cells?

Answer 18

Glycolytic pathway

Pentose phosphate shunt

Question 19

What is the purpose of the pentose phosphate shunt?

Answer 19

Protection from oxidative damage

Question 20

What enzymes can be affected in red cells leading to anaemia?

Answer 20

Glucose-6-phosphate dehydrogenase

Pyruvate kinase

Question 21

What happens to the cell in the absence of glucose-6-phosphate dehydrogenase?

Answer 21

Cell is vulnerable to oxidative damage

Question 22

Why is G6PD deficiency common in malarial areas?

Answer 22

Provides protection from malaria

Question 23

How does G6PD deficiency present?

Answer 23

Variable degrees of anaemia
Neonatal jaundice
Splenomegaly
Pigment gallstones

Question 24

Does illness affect red cell production?

Answer 24

Yes

Question 25

What are triggers to haemolysis in G6PD deficiency?

Answer 25

Infection Acute illness Broad beans Drugs

Question 26

What shifts the oxygen dissociation curve to the left?

Answer 26

Decrease pH Increase in 2,3-diphosphoglycerate Increase in temperature

Question 27

How many alpha and beta chains are in haemoglobin?

Answer 27

2 alpha | 2 beta

Question 28

What happens to haemoglobin in the first year of life?

Answer 28

It is shifted from foetal haemoglobin to haemoglobin A by switching off gamma chains and switching on beta chains

Question 29

What is haemoglobinopathy?

Answer 29

Abnormality of haemoglobin synthesis

Question 30

What is reduced or absent globin chain prouction called?

Answer 30

Thalassaemia alpha or beta depending which chain is affected

Question 31

What is sickle cell disease?

Answer 31

Point mutation of the beta globin chain

Question 32

Is sickle cell disease autosomal recessive or dominant?

Answer 32

Recessive

Question 33

What will be seen under the microscope in a patient with sickle cell?

Answer 33

Some normal cells | Some sickle cells

Question 34

When do red cells sickle?

Answer 34

After deoxygenation

Question 35

What happens to blood vessels in sickle cell patients?

Answer 35

Vaso-occlusion

Question 36

What happens after haemolysis in sickle cell?

Answer 36

Endothelial activation Promotion of inflammation Coagulation activation Dysregulation of vasomotor tone by vasodilator mediatiors

Question 37

What are systemic presentations of sickle cell?

Answer 37

Chest crisis Stroke Hyposplenism Gallstones

Question 38

How is sickle cell managed?

Answer 38

Life long prophylaxis: Vaccination Penicillin and malarial prophylaxis Folic acid

Question 39

How is acute event of sickle cell managed?

Answer 39

``` Hydration Oxygenation Prompt treatment of infection Analgesia Blood transfusion ```

Question 40

What are clinical features of beta thalassaemia major?

Answer 40

``` Severe anaemia Present at 3-6 months of age Expansion of ineffective marrow Bony deformities Splenomegaly Growth retardation ```

Question 41

What is life expectancy for untreated beta thalassaemia major?

Answer 41

<10 years

Question 42

What are different types of thalassaemia?

Answer 42

Homozygous alpha zero thalassaemia Beta thalassaemia major Non-transfusion dependent thalassaemia Thalassasaemia minor

Question 43

How is beta thalassaemia major treated?

Answer 43

Chronic transfusion 4-6 weekly Watch for iron overload - will kill if untreated Iron chelated - iron excreted

Question 44

What drugs can be used for iron chelation therapy?

Answer 44

Desferal | Exjade