Iron deficiency

Question 1

What is the largest store of iron?

Answer 1

Haemoglobin

Question 2

What is the easiest way to detect iron deficiency?

Answer 2

Check the blood

Question 3

Where is iron in the structure of haemoglobin?

Answer 3

In the centre of the haem group

Question 4

What is the typical structure of haemoglobin?

Answer 4

4 haem groups with a globin chain associated to each haem group

Question 5

What makes up the haem ring around the iron in the centre?

Answer 5

Carbon, hydrogen and nitrogen atoms

Question 6

What is the daily required amount of iron?

Answer 6

20mg

Question 7

Where does most of this iron come from?

Answer 7

It is much more than the amount that you consume so most of it is recycled

Question 8

How is iron lost from the body?

Answer 8

Desquamated cells of the skin and gut
Bleeding
Menstruation- one of biggest causes in women

Question 9

How much iron is in the diet per day?

Answer 9

12-15mg

Question 10

What foods contain iron?

Answer 10

Meat and fish- haem iron
Vegetables
Whole grain cereal
Chocolate

Question 11

What happens to most iron that is eaten and why?

Answer 11

It isn’t absorbed because the body can’t absorb ferric iron, only ferrous iron

Question 12

What can affect the absorption of iron from the diet

Answer 12

Orange juice helps

Cups of tea will convert into ferric form

Question 13

What factors will increase iron absorption?

Answer 13

Iron deficiency
Anaemia/hypoxia
Pregnancy

Question 14

What happens to iron when it reaches the gut?

Answer 14

It will pass into epithelial cells but then there is control across the basement membrane of the epithelial cell

Question 15

What do you need at the basement membrane of the epithelial cells to translate iron into the blood?

Answer 15

Ferroportin

Question 16

What is hepcidin?

Answer 16

Regulator of the entry of iron into circulation

Question 17

How does hepcidin work?

Answer 17

When you have high iron levels, you will have high hepcidin levels which will block the ferroportin and stop you from absorbing as much iron

Question 18

How do the iron levels affect the levels of hepcidin?

Answer 18

Hepcidin is a group of proteins that have iron responsive elements within their gene so iron is part of the complex that switches on hepcidin transcription

Question 19

What happens to iron when it enters epithelial cells?

Answer 19

It enters as elemental iron and a protein shell forms around it to form ferritin micelles

Question 20

What happens to the iron once it enters the plasma via ferroportin?

Answer 20

It gets linked to transferrin which transports the iron around the body

Question 21

What is the normal transferrin saturation with iron?

Answer 21

20-40%

Question 22

Wha three things can be measured in relation to transferrin?

Answer 22

Transferrin amount
Total iron binding capacity
Transferrin saturation

Question 23

Where is erythropoietin produced?

Answer 23

Kidneys

Question 24

What happens in terms of erythropoietin if you are hypoxic?

Answer 24

Increase in erythropoietin secretion and hence increase in red blood cell precursors/RBCs

Question 25

What is anaemia of chronic disease?

Answer 25

Anaemia seen in patients with chronic disease e.g. chronic infection, chronic immune activation or malignancy

Question 26

How will the patient with anaemia of chronic disease present?

Answer 26

``` They will: Not be bleeding Not have any bone marrow infiltration Not be iron/B12 or folate deficient No obvious cause except being ill ```

Question 27

What is the most commonly used sign of being ill?

Answer 27

C-reactive protein (CRP)

Question 28

What is CRP?

Answer 28

Acute phase protein that increases in case of infection or inflammation

Question 29

What other signs are used to detect illness?

Answer 29

``` Erythrocyte sedimentation rate (ESR)- rises in response Ferritin- increases Factor VIII Fibrinogen Immunoglobulins ```

Question 30

Which immunoglobulin is high if you're acutely ill?

Answer 30

IgG

Question 31

What conditions are associated with anaemia of chronic disease?

Answer 31

Chronic infections Chronic inflammation Malignancy Miscellaneous

Question 32

What is anaemia of chronic disease due to?

Answer 32

Cytokine release that occurs when someone is unwell

Question 33

What effect does cytokine release have?

Answer 33

``` Cytokines prevent the usual flow of iron from the duodenum to the red cells- they block iron utilisation by red cells Stop erythropoietin from increasing Stop iron flowing out of cells Increase production of ferritin Increase death of red cells ```

Question 34

What do cytokines include?

Answer 34

TNF alpha | Interleukins

Question 35

What are the 4 causes of iron deficiency?

Answer 35

Bleeding - e.g. menstrual/GI Increased use- e.g. growth/pregnancy Dietary deficiency- e.g. vegetarian Malabsorption- e.g. coeliac disease

Question 36

What are the three causes of a low MCV?

Answer 36

Iron deficiency Thalassemia trait Anaemia of chronic disease

Question 37

If you were told that a patient had low serum iron, which of the three causes for low MCV would this rule out?

Answer 37

Thalassaemia (normal serum iron)

Question 38

How would you confirm that a patient has thalassaemia?

Answer 38

Haemoglobin electrophoresis- would confirm there is an additional type of haemoglobin present

Question 39

How would you differentiate between iron deficiency and ACD in a patient with low MCV and low serum iron?

Answer 39

Ferritin Low- iron deficiency High- ACD Transferrin Increases- iron deficiency Normal or low- ACD

Question 40

What does it mean if a man of any age has low ferritin?

Answer 40

They have iron deficiency

Question 41

What are the parameters like in classic iron deficiency?

Answer 41

``` Hb- Low MCV- Low Serum iron- Low Ferritin- Low Transferrin- High Transferrin saturation- Low ```

Question 42

What are the parameters like in classic thalassaemia trait?

Answer 42

``` Hb- Low MCV- Low Serum iron- Normal Ferritin- Normal Transferrin- Normal Transferrin sat- Normal ```