9 - Iron deficiency

Question 1

In what state is the iron in the haem group of haemoglobin?

Answer 1

Fe2+ (ferrous)

Question 2

How much iron do you need per day to maintain the production of red blood cells?

Answer 2

20 mg/day

Question 3

How can iron be lost under normal, non-pathological conditions?

Answer 3

Desquamation of cells in the skin and gut

Bleeding (menstruation is one of the largest causes of loss of iron from the body in women)

Question 4

State some natural foods that are high in iron.

Answer 4

Meat and fish
Vegetables
Whole grain cereal
Chocolate

Question 5

Which form of iron cannot be absorbed?

Answer 5

Fe3+ (ferric)

Question 6

What effect does drinking tea have on iron absorption?

Answer 6

Cups of tea promotes the conversion of Fe2+ to Fe3+

Question 7

Why do meat and fish eaters have an advantage over vegetarians in terms of iron absorption?

Answer 7

They will absorb iron in the haem form

Question 8

State three systemic factors that increase iron absorption.

Answer 8

Iron deficiency
Anaemia/hypoxia
Pregnancy

Question 9

Which channel, on the basement membrane of intestinal epithelial cells, allows movement of iron into the circulation?

Answer 9

Ferroportin

Question 10

What is a key regulator of iron absorption that affects ferroportin?

Answer 10

Hepcidin

Question 11

How is the level of hepcidin affected?

Answer 11

There are certain proteins (such as hepcidin) that have iron-responsive elements in their genes
So iron is part of the complex that switches on hepcidin transcription

Question 12

How is iron stored within cells?

Answer 12

In ferritin micelles

Question 13

What transports iron in the circulation?

Answer 13

Transferrin

Question 14

State three parameters that can be measured that involve transferrin?

Answer 14

Transferrin
Transferrin Saturation
Total Iron Binding Capacity (TIBC)

Question 15

What is the normal transferrin saturation?

Answer 15

20-40%

Question 16

Where is erythropoietin produced and what effect does it have?

Answer 16

Kidneys (stimulated by hypoxia)
Increase in red blood cell precursors
Red blood cell precursors will survive longer and the EPO will make them grow and differentiate to produce more progeny

Question 17

What is anaemia of chronic disease?

Answer 17

Anaemia that is seen in patients with chronic disease

Question 18

What typical signs of anaemia will these patients NOT have?

Answer 18

They will NOT be bleeding
They will NOT be iron deficient, B12 deficient or folate deficient
They will NOT have any bone marrow infiltration

Question 19

State some laboratory signs of being ill.

Answer 19

Raised C-reactive protein (CRP)
Raised Erythrocyte Sedimentation Rate (ESR)
Raised Ferritin
Raised Factor VIII
Raised Fibrinogen
Raised Immunoglobulins

Question 20

State some causes of anaemia of chronic disease

Answer 20

Chronic infections – e.g. TB/HIV
Chronic inflammation – e.g. SLE, rheumatoid arthritis
Malignancy
Miscellaneous (e.g. cardiac failure)

Question 21

What is the underlying cause of ACD?

Answer 21

ACD is due to the cytokine release that happens when someone is unwell
The cytokines block utilisation of iron by red blood cells
They also stop erythropoietin from increasing
Stop iron flowing out of cells
Increase production of ferritin
Increased death of red cells

Question 22

Give examples of cytokines involved in ACD.

Answer 22

TNF-

Interleukins

Question 23

State four broad causes of iron deficiency.

Answer 23

Bleeding
Increased use (e.g. growth, pregnancy)
Dietary deficiency (e.g. vegetarian)
Malabsorption (e.g. Coeliac disease)

Question 24

Under what conditions for iron deficiency are full GI investigations performed?

Answer 24

Male
Women over 40
Post-menopausal women
Women with scanty menstrual loss

Question 25

State some other investigations that can be performed for iron deficiency

Answer 25

Antibodies for coeliac disease | Check for urinary blood loss

Question 26

State three causes of a low MCV(with low Hb) (-microcytic anaemia)

Answer 26

Iron deficiency Anaemia of chronic disease Thalassemia trait

Question 27

How would you confirm thalassemia trait (if you have already confirmed MCV is low)?

Answer 27

Haemoglobin electrophoresis

Question 28

How does serum iron help distinguish between the three causes of microcytic anaemia?

Answer 28

Iron deficiency – LOW serum iron ACD – LOW serum iron Thalassemia – NORMAL serum iron

Question 29

Describe the difference in ferritin levels in iron deficiency and anaemia of chronic disease.

Answer 29

Iron deficiency – LOW | ACD – HIGH (it is an acute phase protein)

Question 30

Why is ferritin not always reliable (when distinguishing between iron deficiency and anaemia of chronic disease)?

Answer 30

Some people may have a chronic disease and be bleeding e.g. rheumatoid arthritis and a bleeding ulcer In this case the ferritin may appear normal You need to check the signs of infection/inflammation such as ESR and CRP to see if there is an underlying condition causing a rise in acute phase proteins

Question 31

Describe the difference in transferrin in iron deficiency and ACD.

Answer 31

Iron deficiency – HIGH | ACD – LOW/NORMAL

Question 32

Describe the difference in transferrin saturation in iron deficiency and ACD.

Answer 32

Iron deficiency – LOW | ACD – NORMAL

Question 33

What is the diagnosis of a man of any age with a low ferritin?

Answer 33

Iron deficiency | He needs upper and lower GI endoscopies to look for the source of the bleeding

Question 34

State what you’d expect the following parameters to be in iron deficiency: a. Hb b. MCV c. Serum Iron d. Ferritin e. Transferrin f. Transferrin Saturation

Answer 34

``` a. Hb LOW b. MCV LOW c. Serum Iron LOW d. Ferritin LOW e. Transferrin HIGH f. Transferrin Saturation LOW ```

Question 35

State what you’d expect the following parameters to be in anaemia of chronic disease: a. Hb b. MCV c. Serum Iron d. Ferritin e. Transferrin f. Transferrin Saturation

Answer 35

``` a. Hb LOW b. MCV LOW/NORMAL c. Serum Iron LOW d. Ferritin HIGH/NORMAL e. Transferrin LOW/NORMAL f. Transferrin Saturation NORMAL ```

Question 36

State what you’d expect the following parameters to be in thalassemia trait: a. Hb b. MCV c. Serum Iron d. Ferritin e. Transferrin f. Transferrin Saturation

Answer 36

``` a. Hb LOW b. MCV LOW c. Serum Iron NORMAL d. Ferritin NORMAL e. Transferrin NORMAL f. Transferrin Saturation NORMAL ```