Anaemia and Haemoglobinopathies

Question 1

In what conditions is there a decrease reticulocyte count?

Answer 1

iron/B12/folate deficiency, bone marrow disease, anaemia of chronic disease

Question 2

In what conditions is there an increased reticulocyte count?

Answer 2

haemolysis
thalassaemia
blood loss

Question 3

What are the causes of microcytic hypochromic anaemia?

Answer 3

iron deficiency
thalassaemia
anaemia of chronic disease
lead poisoning
sideroblastic anaemia

Question 4

What are the causes of normocytic normochromic anaemia?

Answer 4

renal failure
acute blood loss
primary bone marrow failure
drug induced
anaemia of chronic disease

Question 5

What are the causes of macrocytic anaemia?

Answer 5

B12/folate deficiency
cytotoxic drugs
alcohol
myelodysplasia
hypothyroidism
chronic liver disease

Question 6

What does pencil cells on a blood film usually indicate?

Answer 6

iron deficiency

Question 7

What does spherocytes on the blood film usually indicate?

Answer 7

haemolysis

Question 8

What is ferritin?

Answer 8

the main cellular storage form of iron

Question 9

What is the role of hepcidin?

Answer 9

to regulate intestinal iron absorption and the distribution of iron to tissues
high hepcidin decreases dietary iron uptake

Question 10

What causes low hepcidin levels?

Answer 10

iron deficiency
hypoxia
erythropoesis

Question 11

What causes high hepcidin levels?

Answer 11

iron excess

inflammation

Question 12

What happens to hepcidin in chronic haemolytic anaemias and thalassaemias?

Answer 12

hepcidin is decreased despite iron overload

Question 13

What happens to hepcidin in haemochromatosis?

Answer 13

innappropriately suppressed

Question 14

What are the findings on iron studies for iron deficiency anaemia?

Answer 14

decreased serum iron
increased serum transferrin and total iron binding capacity
decreased transferrin saturation
decreased serum ferritin

Question 15

What test is useful to differentiate anaemia of chronic disease with iron deficiency and inflammation?

Answer 15

soluble transferrin receptor

only elevated in iron deficiency

Question 16

What is the structure of haemoglobin?

Answer 16

heterotetramer consisting of two pairs of globin polypeptide chains

Question 17

What makes up haemoglobin A?

Answer 17

two alpha and two beta chains

Question 18

What makes up haemoglobin A2?

Answer 18

two alpha and two delta chains

Question 19

What makes up haemoglobin F (fetal haemoglobin)?

Answer 19

two alpha and two gamma chains

Question 20

What causes a left shift of the oxygen dissociation curve?

Answer 20

decreased temperature, decreased 2-3 DPG, decreased H+, CO

Question 21

What causes a right shift of the oxygen dissociation curve?

Answer 21

increased temp, increased 2-3 DPG, increased H+

Question 22

What makes up haemoglobin H?

Answer 22

beta tetramer

Question 23

Why is haemoglobin H unable to deliver oxygen to tissues?

Answer 23

because it has high affinity for oxygen (won’t give it up at normal tissue oxygen partial pressures)

Question 24

Where are the haemoglobin genes?

Answer 24

alpha gene cluster on short arm of chromosome 16

beta gene cluster on chromosome 11

Question 25

What is the underlying genetic cause of sickle cell anaemia?

Answer 25

homozygous valine for glutamic acid in the 6th position of beta chain

Question 26

What is the underlying genetic cause of sickle cell disease?

Answer 26

valine for glutamic acid on one beta chain with coinheritence of beta thalassaemia gene

Question 27

What causes haemoglobin E?

Answer 27

G->A substitution in codon 26 of the beta globin gene

Question 28

What causes alpha thalassaemia?

Answer 28

usually deletion of one or both alpha globin gene

Question 29

What are the consequences of thalassaemia?

Answer 29

``` increased haemolysis ineffective/increased erythropoesis iron overload extramedullary haemopoesis bony expansion (frontal bossing) high output cardiac failure osteoporosis endocrinopathy renal impairment ```

Question 30

What is the initial screening test for thalassaemia?

Answer 30

HPLC

Question 31

What is the management for transfusion dependent thalassaemia?

Answer 31

tranfuse to Hb > 100 to reduce erythropoesis drive | iron chelation

Question 32

What used to be the major cause of death in thalassaemia?

Answer 32

cardiomyopathy from iron overload