Anaemia (Microcytic & Anaemia of Chronic Disease)

Question 1

Question 2

What is the most common cause of microcytic anaemia? [1]

State 5 causes of the above [5]

Answer 2

The most common cause in adults is blood loss:
- menstruating women
- cancer
- peptic ulcers
- IBD
- Angiodysplasia

Question 3

The major causes of IDA can be grouped into three categories. What are they? [3]

Answer 3

Increased requirements (e.g. pregnancy, lactation)

Increased loss (e.g. gastrointestinal bleeding)

Decreased uptake (e.g. dietary deficiency, malabsorption)

Question 4

Where is iron absorbed in the gut? [2] Why? [1]

Answer 4

Duodenum and upper jejunum: best absorbed in acidic environment

(chyme is located here)

Question 5

What is different between haem and non haem iron? [1]

Answer 5

haem iron is more bioavailable and is sourced from chicken / beef / duck.

Question 6

Explain the mechanism of iron absorbtion and transport in the body for haem iron and non haem iron [5]

Describe how hepcidin works within this cycle [2

Answer 6

Haem iron

1. Absorbed through DMT1
2. Fe removed from Haem. Can then be stored as ferritin OR can exit cell through ferroportin

Non-haem iron:

1. Mostly in the form of Fe3+, but only Fe2+ can be absorbed by enterocytes. Enzyme reductase: Fe3+ –> Fe2+
2. Enters via DMT1
3. Fe removed from Haem. Can then be stored as ferritin OR can exit cell through Ferroportin

Then transferrin transports Fe3+ around body

Hepcidin:
1. Blocks ferroportin (the transporter of Fe2+ into blood)
2. Therefore is a negative regulator of iron.

Question 7

Iron deficiency can sometimes make patients (especially children) crave to eat what? [1]

What is the name for this? [1]

Answer 7

Pica: craving eating dirt or soil

Question 8

What are specific signs associated with anaemia of iron deficiency? [4]

Answer 8

• Koilonychia (spoon shaped nails)
• Angular stomatitis (inflammation of corners of mouth)
• Restless legs syndrome
• Hair loss
• Post-cricoid webs

Question 9

Name 7 risk factors for IDA

Answer 9

• pregnancy
• vegetarian and vegan diet
• menorrhagia
• hookworm infestation
• chronic kidney disease
• coeliac disease
• gastrectomy/achlorhydria
• non-steroidal anti-inflammatory drug (NSAID) use
• chronic heart failure

Question 10

What are specific signs associated with anaemia of thelessasmia? [1]

Answer 10

abnormal bone facial development

Question 11

Why do PPIs interfere with Fe absorption? [1]

Answer 11

Fe is best absorbed in an acidic environment

Proton pump inhibitors (e.g., omeprazole), can interfere with iron absorption as they reduce stomach acid

Question 12

Describe what is meant by total iron-binding capacity (TIBC).

Describe how low / high iron levels influence TIBC [1]

Answer 12

Total iron-binding capacity (TIBC):
- the capacity of transferrin to bind with iron

When iron stores are depleted, the TIBC levels increase in the blood

When iron stores are normal, the TIBC levels are low / normal

When are iron stores are high, the TIBC levels are low

Question 13

Describe what is meant by transferrin saturation [1]

What is the formula for transferrin saturation? [1]

Answer 13

Transferrin saturation refers to the proportion of the transferrin molecules bound to iron, expressed as a percentage.

Transferrin saturation = serum iron / total iron-binding capacity

Question 14

How does inflammation influence ferritin levels? [1]

Answer 14

Inflammation causes release of ferritin

Question 15

What does low ferritin levels indicate? [1]

Answer 15

IDA

Question 16

Why does normal ferritin not exclude iron deficiency? [1]

Answer 16

Because ferritin could be released due to an acute stage of inflammation (masking IDA)

Question 17

What do raised ferritin levels indicate? [4]

Answer 17

Inflammation (e.g., infection or cancer)
Liver disease
Iron supplements
Haemochromatosis

Question 18

Describe how you would investigate for IDA

Answer 18

FBC:
- Low Hb / haemotocrit
- Low platelet count
- Reduced MCV
- Microcytic blood smear
- Low reticulocyte count
- Increased TIBC
- Low transferrin saturation

Question 19

A patient presents with IDA without a clear underlying cause. What is the next stage in investigating this patient? [2]

Answer 19

colonoscopy and oesophagogastroduodenoscopy (OGD) for malignancy.

Question 20

Describe the management of IDA [3]

Answer 20

1ST LINE
- oral iron replacement (ferrous sulfate)
- 200 mg once daily

2ND LINE
- intravenous iron replacement

3rd LINE:
- Blood transfusion

Question 21

Describe what would describe to a patient about taking oral iron [2]

Answer 21

Oral iron works slowly. A rise in haemoglobin of 20 grams/litre is expected in the first month.

Common side effects are constipation, naseua, **abdominal pain & **black stools.

Question 22

Under which conditions are iron transfusions contraindicated? [1]
Why? [1]

Answer 22

It should be avoided during infections, as there is potential for it to “feed” the bacteria.

Question 23

Desribe how ACD presents with regards to Hb [1]

Answer 23

ACD is classically described as a normocytic, normochromic anaemia secondary to systemic diseases, infection or malignancy.

Question 24

Describe the pathophysiology of ACD [2]

Answer 24

Hepcidin is acute phase protein that usually works to reduce the availability of iron from infecting microorganisms.

Chronic inflammation mediated by IL-6 can lead to a hepcidin-induced block of iron absorption and iron release from macrophages

This reduction in the availability of iron for the production of erythrocytes as part of erythropoiesis can lead to a microcytic anaemia. However, this is only seen in 25% of cases.

Question 25

Describe the FBC result for ACD [2]

Answer 25

The FBC may show a normocytic normochromic anaemia (approx. 75%)
or
a microcytic anaemia (approx. 25%).

In ACD, the MCV is rarely below 70 fL.

Question 26

Describe how Fe tests would help to diagnose ACD [3]

Answer 26

The clinical presentation of ACD is generally that of the underlying disorder

Serum ferritin:
- Normal or raised (due to release during inflammation)

Serum iron:
- Low

TIBC:
- Low