Macrocytic Anaemia

Question 1

What is macrocytic anaemia?

Answer 1

Anaemia where the red cells have a larger than normal volume

Question 2

How is mean cell volume measured?

Answer 2

Femtolitres

Question 3

What are the blood results for macrocytic anaemia?

Answer 3

Low Hb
Low RBC
High MCV

Question 4

What MCV is macrocytic?

Answer 4

> 100fl

Question 5

What are the blood results for Macrocytosis?

Answer 5

Normal Hb
Normal RBC
High MCV

Question 6

What are the 2 types of macrocytosis?

Answer 6

Megaloblastic

Non-megaloblastic

Question 7

What is megaloblastic macrocytosis?

Answer 7

Bone marrow produces large, structurally abnormal immature red blood cells (Megaloblasts)

Question 8

How do immature RBCs become erythrocytes?

Answer 8

1. Accumulate Hb
2. Decrease in Size
3. Stop dividing
4. Lose Nucleus

Question 9

What is a megaloblast?

Answer 9

Large nucleated red cell precursor with immature nucleus

Question 10

How does a megaloblast become a macrocyte?

Answer 10

When haemoglobin is optimal the nucleus is extruded leaving an enlarged red cell (a macrocyte)

Question 11

Why are macrocytes big?

Answer 11

Failure to become smaller

Question 12

What are the causes of macrocytic anaemia?

Answer 12

B12 deficiency
Folate deficiency
Drugs

Question 13

What can cause a B12 deficiency?

Answer 13

Veganism
Gastric problems
-Chrons
-Surgery
-Deficiency
-Pancreatitis

Question 14

What is pernicious anaemia?

Answer 14

Autoimmune condition with destruction of gastric parietal cells
Intrinsic factor deficiency
B12 malabsorption and deficiency

Question 15

How is dietary folate absorbed?

Answer 15

Converted to monoglutamate and absorbed in the jejunum

Question 16

Where do humans get B12 from?

Answer 16

animals

Question 17

How long can B12 stores last?

Answer 17

2-4 years

Question 18

Where is B12 absorbed?

Answer 18

Ileum

Question 19

How much B12 is required per day?

Answer 19

1.5ug

Question 20

Where do humans get Folate from?

Answer 20

Liver

Leafy veg

Question 21

How long can folate stores last?

Answer 21

4 months

Question 22

Where is folate absorbed?

Answer 22

Duodenum

Jejunum

Question 23

How much folate is required per day?

Answer 23

200ug

Question 24

What causes folate deficiency?

Answer 24

Poor intake
Alcoholism
Malabsorption
Utilisation
Anti-convulsants

Question 25

What utilises folate stores?

Answer 25

Haemolysis Pregnancy Dermatitis Malignancy

Question 26

What are the symptoms of B12 and folate deficiency?

Answer 26

``` Anaemia signs Weight loss Diarrhoea Infertility Sore tongue Jaundice ```

Question 27

What symptoms are specific to B12 deficiency?

Answer 27

Neurological problems Dorsal column abnormalities Neuropathy dementia

Question 28

How can macrocytic anaemia be diagnosed?

Answer 28

``` Low RCC Macrovalocytes on Blood film Hypersegmented neutrophils B12 and folate levels Auto-antibodies ```

Question 29

What autoantibodies should be looked for in macrocytic anaemia?

Answer 29

Anti-Intrinsic Factor | Anti-Gastric Parietal cell

Question 30

What is the treatment for Megalobastic anaemia?

Answer 30

Treat cause B12 injections for life Folic acid 5mg daily

Question 31

When should a transfusion be done?

Answer 31

If anaemia is life threatening

Question 32

What is spurious macrocytosis?

Answer 32

Normal red cell volume but measured as high`

Question 33

What can cause spurious macrocytosis?

Answer 33

``` Reticulocytosis Cold agglutination (clumps) ```

Question 34

Why can patients with pernicious anaemia be jaundiced?

Answer 34

Intramedullary haemolysis Red cells die in bone marrow Hb is released Converted to bilirubin