Haem - Anaemia, IDA, B12+pernicious anaemia, Thalassaemia

Question 1

Anaemia - what is the definition of anaemia?

Answer 1

Defined as low level of Haemoglobin in the blood

Question 2

Anaemia - what is mean cell volume?

Answer 2

This is the size of the RBCs

Question 3

Anaemia - what are the three categories MCV can be divided into?

Answer 3

Microcytic anaemia - low MCV, small RBCs

Normocytic anaemia - normal MCV, normal sized RBCs

Macrocytic anaemia - high MCV, large RBCs

Question 4

Anaemia - what are microcytic anaemia causes?

Answer 4

TAILS

Thalassaemia
Anaemia of chronic disease
Iron Deficiency Anaemia
Lead poisoning
Sideroblastic anaemia

Question 5

Anaemia - what are normocytic anaemia causes?

Answer 5

AAAHH or AHAHA

Acute blood loss
Anaemia of chronic disease
Aplastic anaemia
Hypothyroidism
Haemolytic anaemia

Question 6

Anaemia - what two categories can macrocytic anaemia causes be divided into and what are the causes?

Answer 6

Megaloblastic anaemia - impaired DNA synthesis, prevents cell from dividing normally, so cell grows into larger abnormal cell, caused by VITAMIN DEFICIENCY:

1. B12 deficiency
2. Folate deficiency

Normoblastic macrocytic anaemia:

1. Alcohol
2. Reticulocytosis
3. Hypothyroidism
4. Liver disease
5. Drugs - azathioprine

Question 7

Anaemia - what are the symptoms?

Answer 7

Fatigue
SoB
Palpitations
Headaches
Dizziness
Worsening of other conditions

Question 8

Anaemia - what are some signs?

Answer 8

Pale skin
Conjunctival pallor
Tachycardia
Increased resp rate

Question 9

Iron Deficiency Anaemia (IDA) - what are some reasons as to why a patient may become iron deficient?

Answer 9

1. Insufficient dietary iron
2. Iron requirements increase (pregnancy)
3. Iron being lost (bleeding, menorrhagia)
4. Malabsorption

Question 10

IDA - where is iorn mainly absorbed?

Answer 10

Duodenum and Jejunum

Question 11

IDA - what medications reduce stomach acid, and why is this a problem in IDA?

Answer 11

PPIs

Duo and Jej need soluble form of iron to absorb, which requires stomach acid to stay in that soluble form, but PPIs reduce stomach acid, so it changes to Fe3+ insoluble form, so interferes with Fe absorption

Question 12

IDA - what is transferrin?

Answer 12

Carrier protein that binds iron

Question 13

IDA - what is total iron binding capacity (TIBC)?

Answer 13

Total space on the transferrin molecule for the iron to bind

Question 14

IDA - what is transferrin saturation, and what is the equation?

Answer 14

Proportion of transferrin molecules that are bound to iron

Transferrin Saturation = Serum iron / TIBC

Question 15

IDA - what is ferritin?

Answer 15

Ferritin is the form iron takes when it is deposited and stored in cells

If serum ferritin low, highly suggestive of IDA

Question 16

IDA - what would you see on blood results?

Answer 16

Increased TIBC

Increased transferrin

Decreased transferrin saturation

Decreased Ferritin

Decreased serum iron

Question 17

IDA - what would you see on a blood film?

Answer 17

Poikilocytes - abnormally shaped RBCs

Question 18

IDA - management?

Answer 18

PO ferrous sulphate/fumarate, 200mg TDS:
Give Vit C to aid absorption
Can take 3-6 months
SE - N+V, black stools
UNSUITABLE when MALABSORPTION is cause

IV iron:
Quickly corrects ID
Avoided during sepsis, as iron ‘feeds’ bacteria

Question 19

B12 deficiency and Pernicious anaemia - what is it?

Answer 19

Pernicious anaemia is a cause of B12 (cobalamin) deficiency

B12 deficiency can be caused by insufficient diet of B12 or pernicious anaemia

Question 20

B12 deficiency and Pernicious anaemia - function of B12?

Answer 20

B12 and folate aid DNA synthesis

B12 aids myselin formation

Question 21

B12 deficiency and Pernicious anaemia - pathophysiology of B12 absorption

Answer 21

• Gastric parietal cells produce protein called intrinsic factor (IF)
• B12 binds to IF, B12-IF complex can then be absorbed in terminal ileum

Question 22

B12 deficiency and Pernicious anaemia - what is pernicious anaemia?

Answer 22

Autoimmune condition where antibodies destroy gastric parietal cells or IF itself

Lack of IF prevents absorption of vitamin B12

Question 23

B12 deficiency and Pernicious anaemia - what are the investigations and results?

Answer 23

1st line: IF antibody test

Bloods

FBC:

1. Decresased Hb
2. Increased MCV (as megaloblastic anaemia)

Decreased serum cobalamin

Question 24

B12 deficiency and Pernicious anaemia - what is the management?

Answer 24

1st line if problem is absorption - Hydroxycobalamin IM, 3 times weekly for 2 weeks, then every 3 months

1st line if dietary deficiency - cyanocobalamin

Question 25

Thalassaemia - what is it?

Answer 25

Alpha and Beta Thalassaemia are autosomal recessive disorders, which are cuased by a mutation that leads to dysfunction of either the alpha-globin or beta-globin chains on the Hb molecule

Question 26

Thalassaemia - pathophysiology

Answer 26

* In thalassaemia, blood cells more fragile * Break down more easily * Spleen acts as a sieve to filter RBCs and remove RBCs * In thalassaemia, spleen collects destroyed RBCs and swells - **splenomegaly** * Bone marrow expands to produce more RBCs to compensate for anaemia, causes **pronounced forehead and malar eminences**

Question 27

Thalassaemia - signs and symptoms

Answer 27

1. Microcytic anaemia 2. Pallor 3. Jaundice 4. Gallstones 5. Splenomegaly 6. Pronounced head and eminences 7. Poor growth

Question 28

Thalassaemia - investigations

Answer 28

FBC - **Microcytic anaemia** Haemoglobin electrophoresis DNA testing

Question 29

Thalassaemia - what can occur in thalassaemia in response to anaemia?

Answer 29

Iron overload

Question 30

Thalassaemia - why does iron overload occur, and what is the management?

Answer 30

Faulty creation of RBCs Recurrent transfusions Increased absorption of iron in response to anaemia Management - limit transfusions, iron chelation

Question 31

Thalassaemia - alpha thalassaemia causes what impairment?

Answer 31

Alpha thalassaemia leads to impaired oxygen transport extravascular haemolysis

Question 32

Thalassaemia - beta thalassameia causes what abnormality?

Answer 32

Leads to failed erythropoiesis Build up of alpha chains causing cell destruction Compensatory erythroid hyperplasia causes bone growth

Question 33

Thalassaemia - investigations

Answer 33

Bloods: Decreased Hb Decreased MCV RBCs may be normal or high Increased reticulocytes **Diagnosis: HB electrophoresis** Liver biopsy if iron overload

Question 34

B12 deficiency and Pernicious anaemia - what is the presentation?

Answer 34

Megaloblastic anaemia 1. Neurological symptoms - **peripheral neuropathy** with numbness or paraesthesia, impaired cognition, psychosis, impaired proprioception 2. Glossitis 3. Angular cheilitis

Question 35

B12 deficiency and Pernicious anaemia - what are some causes?

Answer 35

**Impaired absorption -** crohn's, ileal resection **Diet -** vegan diet, malnutrition **Drugs -** PPIs, metformin, alcohol

Question 36

IDA - what are the soluble and insoluble forms of iron?

Answer 36

Soluble: Ferrous Fe2+ Stomach acid required to keep iron in soluble form, if acid levels drop, it changes to insoluble form Ferric Fe3+

Question 37

Anaemia - what two categories can macrocytic anaemia causes be divided into and what are the causes?

Answer 37

Megaloblastic anaemia - impaired DNA synthesis, prevents cell from dividing normally, so cell grows into larger abnormal cell, caused by VITAMIN DEFICIENCY: 1. B12 deficiency 2. Folate deficiency Normoblastic macrocytic anaemia: 1. Alcohol 2. Reticulocytosis 3. Hypothyroidism 4. Liver disease 5. Drugs - azathioprine