Iron Deficiency and Anaemia of Chronic Disease

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?
How much iron does the human diet normally provide?

Answer 2

20 mg/day

Diet: 12-15 mg/day

Question 3

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

Answer 3

Desquamation of cells in the skin + gut

Bleeding (menstruation is 1 of the largest causes of loss of iron from the body in women)

Question 4

State 4 foods that are high in iron.

Answer 4

Meat + fish
Vegetables
Whole grain cereal
Chocolate

Question 5

Which form of iron cannot be absorbed? What effect does drinking tea have on iron absorption?

Answer 5

Fe3+ (ferric)

Tea promotes the conversion of Fe2+ to Fe3+

Question 6

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

Answer 6

They absorb iron in the haem form

Question 7

State 3 systemic factors that increase iron absorption.

Answer 7

Iron deficiency
Anaemia/ hypoxia
Pregnancy

Question 8

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

Answer 8

Ferroportin

Question 9

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

Answer 9

Hepcidin

Question 10

How is the level of hepcidin affected?

Answer 10

Certain proteins (e.g. hepcidin) have iron-responsive elements in their genes  
So iron is part of the complex that switches on hepcidin transcription
High iron = high hepcidin = low ferroportin = low absorption

Question 11

How is iron stored within cells?

Answer 11

In ferritin micelles

Question 12

What transports iron in the circulation?

Answer 12

Transferrin

Question 13

State 3 parameters that can be measured that involve transferrin?

Answer 13

Transferrin
Transferrin Saturation
Total Iron Binding Capacity (TIBC)

Question 14

What is the normal transferrin saturation?

Answer 14

20-40%

Question 15

Where is erythropoietin produced and what effect does it have?

Answer 15

Kidneys (stimulated by hypoxia)
Increase in RBC precursors
RBC precursors will survive longer + EPO will make them grow + differentiate to produce more progeny

Question 16

What is anaemia of chronic disease?

Answer 16

Anaemia in patients with chronic disease

Question 17

What 3 typical signs of anaemia will patients with ACD NOT have?

Answer 17

NO bleeding
NOT iron deficient, B12 deficient or folate deficient
NO bone marrow infiltration

Question 18

State 3 laboratory signs of being ill.

Answer 18

Raised C-reactive protein (CRP)
Raised Erythrocyte Sedimentation Rate (ESR)
Raised acute phase response proteins: Ferritin, Factor VIII, Fibrinogen,Immunoglobulins

Question 19

State 4 causes of anaemia of chronic disease.

Answer 19

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

Question 20

What is the underlying cause of ACD?

Answer 20

ACD is due to the cytokine release that happens when someone is unwell
Cytokines block utilisation of iron by RBCs
Stop erythropoietin from increasing
Stop iron flowing from duodenum to red cells
Increase production of ferritin
Increased death of red cells

Question 21

Give 2 examples of cytokines involved in ACD.

Answer 21

TNF- alpha

Interleukins

Question 22

State 4 broad causes of iron deficiency.

Answer 22

Bleeding e.g. Menstrual, GI
Increased use e.g. growth, pregnancy
Dietary deficiency e.g. vegetarian
Malabsorption e.g. Coeliac disease

Question 23

Under what conditions are full GI investigations performed?

Answer 23

When good diet with no coeliac antibodies +
Male 
Women >40 
Post-menopausal women 
Women with scanty menstrual loss

Question 24

State 2 non-invasive investigations that can be performed for iron deficiency

Answer 24

Antibodies for coeliac disease

Check for urinary blood loss

Question 25

State 3 causes of a low MCV.

Answer 25

Iron deficiency Anaemia of chronic disease (low or normal) Thalassemia trait

Question 26

How would you confirm thalassemia trait?

Answer 26

Haemoglobin electrophoresis

Question 27

How does serum iron help distinguish between the 3 causes of microcytic anaemia?

Answer 27

Iron deficiency – LOW serum iron ACD – LOW serum iron Thalassaemia trait- NORMAL serum iron

Question 28

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

Answer 28

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

Question 29

Why is ferritin not always reliable?

Answer 29

Some people may have a chronic disease + be bleeding e.g. RhA + a bleeding ulcer- here, ferritin may appear normal Need to check the signs of infection/inflammation e.g. ESR + CRP to see if there is an underlying condition causing a rise in acute phase proteins

Question 30

Describe the difference in transferrin in iron deficiency and ACD.

Answer 30

Iron deficiency: HIGH | ACD: LOW/NORMAL

Question 31

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

Answer 31

Iron deficiency: LOW (iron levels have decreased) | ACD: NORMAL (transferrin levels have also decreased)

Question 32

State what you’d expect the following parameters to be in iron deficiency: Hb, MCV, Serum Iron, Ferritin, Transferrin + Transferrin Saturation

Answer 32

``` Hb: LOW MCV: LOW Serum Iron: LOW Ferritin: LOW Transferrin: HIGH Transferrin Saturation: LOW ```

Question 33

State what you’d expect the following parameters to be in anaemia of chronic disease: Hb, MCV, Serum Iron, Ferritin, Transferrin + Transferrin Saturation

Answer 33

``` Hb: LOW MCV: LOW / NORMAL Serum Iron: LOW Ferritin: HIGH / NORMAL Transferrin: NORMAL / LOW Transferrin Saturation: NORMAL ```

Question 34

State what you’d expect the following parameters to be in thalassemia trait: Hb, MCV, Serum Iron, Ferritin, Transferrin + Transferrin Saturation

Answer 34

``` Hb: LOW MCV: LOW Serum Iron: NORMAL Ferritin: NORMAL Transferrin: NORMAL Transferrin Saturation: NORMAL ```

Question 35

What are full GI investigations?

Answer 35

Upper GI endoscopy Duodenal biopsy Colonoscopy Small bowel meal + follow through