Anaemia (+ Iron)

Question 1

What is erythropoiesis and where does it occur?

Answer 1

Making of red blood cells

In the bone marrow

Question 2

What removes the red blood cells?

Answer 2

Reticuloendothelial system (main organ=spleen)

Question 3

What is dyserythropoiesis?

Answer 3

Abnormal/incorrect formation of RBCs

Question 4

If there are problems with haemoglobin synthesis, anaemia can result. What two conditions involve a problem with haemoglobin synthesis?

Answer 4

Thalassaemia

Sickle cell disease

Question 5

What is thalassaemia?

Answer 5

Reduced rate of synthesis of normal alpha/beta globin chains

Question 6

What is sickle cell disease?

Answer 6

Synthesis of an abnormal haemoglobin

Caused by inheritance of the sickle beta globin chain

Question 7

What is the exact mutation that causes sickle cell disease?

Answer 7

A point mutation causing the substitution of valine for glutamic acid in the beta chain (position six)

Question 8

How is sickle cell disease inherited?

Answer 8

Usually autosomal recessive but there are cases where there is 1 sickle cell allele and then another abnormal Hb mutation allele which can have the same sickling effect.

Can be a carrier (and can protect against malaria)

Question 9

What are the symptoms of sickle cell disease?

Answer 9

Symptoms of anaemia usually mild ie the anaemia is well tolerated as HbS readily gives up oxygen in comparison to HbA

**the clinical pattern of disease is very variable between individuals

Question 10

What are the clinical problems associated with sickle cell disease?

Answer 10

Crises:

• vaso-occlusive = pain and organs effected (chest and spleen)
• aplastic
• Haemolytic

Other organ damage

Problems more likely to occur if it is cold, there are infections etc

Question 11

What effect does thalassaemia have on the Hb levels and the size of RBCs?

Answer 11

Low Hb level

Thus microcytic red cells

Question 12

What effect does thalassamia have on the breakdown of RBCs?

Answer 12

It increases it because the spleen and the rest of the reticuloendothelial system recognise the cells as faulty.

As a result the body must make more blood else where in the body

Question 13

What is extramedullary haemopoeisis and why would it occur?

Answer 13

Making blood outside of the bone marrow (ie in the spleen, liver)

When the bone marrow isn’t making correct RBCs ie in thalassaemia

Question 14

What issues does extramedullary haemopoeisis cause?

Answer 14

Splenomegaly
Hepatomegaly
Expansion of haemopoiesis into the bone cortex which impairs growth and causes skeletal abnormalities

Question 15

How does the body try to cope with thalassaemia? What can this cause?

Answer 15

Extramedullary haemopoiesis
Stimulation of EPO

Iron overload

Question 16

How is thalassaemia treated?

Answer 16

Transfusions, iron chelation (drugs to absorb iron), folic acid (stop secondary folate deficiency), immunisation, holistic care (cardiology, endocrine and psycholocal.) stem cell transplantation in some

Question 17

What are the 3 classifications of beta-thalassaemia?

Answer 17

B-thalassaemia: Major and minor and intermedia

Question 18

What are the 4 classifications of alpha thalassaemia?

Answer 18

Silent carrier state
Alpha thalassaemia trait
Haemoglobin H (HbH) disease
Hydrophobic fetalis

Question 19

Explain how myelofibrosis can lead to anaemia

Answer 19

Heavilt fibrotic marrow-little space for haemopoiesis

Blood film shows cells looking like teardrops

Due to lack of erythropoiesis, extramedullary haemopoiesis occurs which causes splenomegaly

The increased size of the spleen also leads to the increased activity of the reticuloendothelial system and more red blood cells are broken down

Less produced + more broken down = anaemia

Question 20

Explain how thalassaemia causes anaemia

Answer 20

Hb synthesis is effected

Those cells that are produced are defected

Which increase the removal of them

Extramedullary haemopoiesis also occurs so we get splenomegaly

Decreased production + increases removal = anaemia

Question 21

Why might anaemia develop?

Answer 21

In Bone marrow:

1) abnormal erythropoiesis
2) abnormal haemoglobin synthesis

In peripheral red blood cells:

3) abnormal function
4) abnormal structure
5) abnormal metabolism

6) excessive blood loss

Removal:
7) abnormal function of RES

Question 22

What is hypochromic anaemia?

Answer 22

Condition in which the red cells are paler than normal

Question 23

What is rouleaux?

Answer 23

When cells stack together

Question 24

What is anisocytosis?

Answer 24

When there are unequal sized RBCs

Question 25

What signs might a doctor find on someone who has anaemia?

Answer 25

Pale skin
Tachycardia
Heart murmur
Epigastric tenderness

Question 26

Explain how the body adapts to anaemia

Answer 26

1. Tachycardia
2. Increased levels of erythropoietin from kidneys
3. Increase stroke volume of heart (to increase CO)
4. Make more 2,3 BPG to increase oxygen release

Question 27

If you suspect someone to have anaemia due to an iron deficiency what is the most appropriate blood test to confirm this? Will the result be higher or lower than normal ranges?

Answer 27

Serum ferritin (as it reflects iron stores in macrophages and the liver)
It would be lower than normal

Question 28

Iron deficiency can cause changed in epithelial cells. Why might this happen?

Answer 28

You need iron for certain enzymes

The cells that are most effected by an iron deficiency are those with a high metabolic rate and the epithelial cells are constantly undergoing mitosis so need a lot of ATP and metabolism.

Question 29

What kind of environment is better for iron absorption?

Answer 29

An acidic environment (low pH)

Question 30

What are reticulocytes? What would the effect of a low Hb level on the reticulocyte count?

Answer 30

Immature RBC

You would expect it be increased to compensate

Question 31

What blood tests might help identify the causes of anaemia?

Answer 31

1. FBC
2. Haemotinic screen (ferritin levels etc)
3. CRP - shows inflammation (indicative of anaemia of chronic disease?)
4. U and Es, renal function test (looking for renal problems)
5. Haemolysis screen: LDL, bilirubin levels