15 - Anaemia 2

Question 1

What are B12 and folate needed for

Answer 1

DNA synthesis
convert homocysteine into methionine
Cells cannot divide - overlarge RBC

Question 2

Another name for vitamin B12

Answer 2

cobalamin (water soluble)

Question 3

What is the function of B12

Answer 3

Vital for myelin synthesis in the NS

Assists in DNA synthesis in every cell in the body

Question 4

How is B12 measured

Answer 4

increase in serum methylmalonic acid

Question 5

How does methionine synthase use B12

Answer 5

uses B12 to transfer a methyl group from 5-methyltetrahydrofolate to homocysteine

Question 6

What does methionine synthase generate

Answer 6

tetrahydrofolate (THF) and methionine

Question 7

What can prolonged B12 deficiency cause?

Answer 7

irreversible nervous system damage

Question 8

What can slight deficiency of B12 cause?

Answer 8

fatigue, lethargy, depression, poor memory, breathlessness, pale skin

Question 9

Where is B12 found?

Answer 9

Meat, eggs, animal protein – not destroyed by cooking

Question 10

How much cobalamin do we need a day and how much do we store?

Answer 10

1ug/d

1000g - 3 year store

Question 11

What is B12 bound to to be absorbed and where is it absorbed

Answer 11

Intrinsic Factor

Ileum

Question 12

Is folate (Vitamin B9) water soluble

Answer 12

Yes -

Question 13

Where is vitamin B9 found

Answer 13

Liver, greens, yeast but destroyed by cooking

Question 14

How much folate do we require and how much do we store

Answer 14

150ug/d

Store enough for 4 months

Question 15

Where is vitamin B9 absorbed?

Answer 15

duodenum and jejunum

Question 16

What does the blood count of B12 and B9 deficiency look like

Answer 16

Reduced Hb - overlarge rbc cannot bend
Increased MVC
Decreased WBC and platelets - high turn over with DNA synthesis

Question 17

What does a blood film look like with B12 or B9 deficiency?

Answer 17

Oval macrocytes and hyper segmented neutrophils (more than 4 lobes)

Question 18

What is biochemistry like with B12 or B9 deficiency?

Answer 18

• Increase in lactate dehydrogenase (LDH)

- Increase in bilirubin – more haemolysis

Question 19

What are the main causes of B12 deficiency

Answer 19

Poor diet
Malabsorption
Gastric – Pernicious Anaemia, Surgical gastrectomy
Intestinal – Illeal disease e.g Chrons

Question 20

What is pernicious anaemia

Answer 20

B12 deficiency caused by the absence of intrinsic factor

Autoimmune disorder

Question 21

What blood group is pernicious anaemia associated with?

Answer 21

Blood group A

Question 22

What are the autoantibodies against in pernicious anaemia?

Answer 22

Gastric mucosa and IF

Question 23

Apart from anaemia, what does pernicious anaemia lead to?

Answer 23

gastric atrophy, decrease in acid and decrease in IF secretion

Question 24

Clinical features of pernicious anaemia

Answer 24

Insidious, anaemia, glossitis, jaundice, neurological symptoms (neuropathy, dementia, damage to sensory and motor tracts)

Question 25

What is the treatment of pernicious anaemia?

Answer 25

Intramuscular B12 every 3 months for life

Question 26

Why is intramuscular B12 given

Answer 26

Bc the B12 cannot be absorbed in the gut due to no IF workage

Question 27

What are causes of folate deficiency

Answer 27

• Nutrition – old age, poverty, alcoholism
• Malabsorption – Coeliac, Chrons
• Excess utilisation – Pregnancy, lactation, haemolytic anaemias, psoriasis
• Others – anticonvulsants

Question 28

Difference between folate deficiency and B12 deficiency

Answer 28

No neurological signs in folate deficiency

Question 29

What is the treatment for folate deficiency?

Answer 29

Oral folic acid

Question 30

What are the causes of haemolytic anaemia

Answer 30

Damaged membrane
Haemoglobin damage (SCD and thalassaemia)
Enzyme damage

Question 31

What does G6PD do

Answer 31

G6PD prevents/reverses oxidation of Hb, membrane etc; prolongs lifetime of RBC.

Question 32

Where is G6PD deficiency most common

Answer 32

Tropical africa
middle east
subtropical asia
Mediterranean

Question 33

What is G6PD heritability

Answer 33

X-linked

Question 34

How can a G6PD carrier show symptoms

Answer 34

Exposed to triggers
e.g foods such as fava beans
bacterial or viral infection
drugs e.g dapsone, cotrimoxazole, primaquine

Question 35

Example of extra vascular haemolysis

Answer 35

SDC, Thalassaemia, o Antibody-induced haemolytic anaemia
o Rhesus mismatched transfusion
o Hereditary spherocytosis

Question 36

What is hereditary spherocytosis

Answer 36

Membrane not forming double dimple
sphere shape and high fragility
- chronic haemolytic anaemia

Question 37

What is the inheritance of hereditary spherocytosis?

Answer 37

Autosomal dominant

Question 38

What are some causes of intravascular haemolysis?

Answer 38

ABO mismatched transfusion
Snake bites
Infections (Babesia, Clostridium)

Question 39

What is the presentation of haemolytic anaemia?

Answer 39

Pallor and anaemia
Jaundice
Gallstones – urobilogen
Splenomegaly

Question 40

What would lab investigations be to indicate increased red cell breakdown

Answer 40

↑ serum unconjugated bilirubin
↑ urinary urobilinogen
↑ lactate dehydrogenase
Heptaglobin goes down

Question 41

What would lab investigations be to indicate increased red cell production

Answer 41

↑ reticulocytes in blood

↑ RBCs in marrow

Question 42

What are the antibodies that are present in the blood and react with RBC membrane proteins in autoimmune haemolytic anaemia?

Answer 42

IgG

Question 43

How can you prove there is antibody on a rbc?

Answer 43

Coombs test

- Take blood sample and wash and the cells will agglutinate with anti-human antibodies

Question 44

What are causes of autoimmune haemolyic anaemia?

Answer 44

50% idiopathic
Secondary - drugs, penicillin, CT disease (Systemic lupus erythematosus)
Blood transfusion