Erythropoiesis + Anaemias

Question 1

What is a reticulocyte?

Answer 1

Immediate precursor of a mature red blood cell

Question 2

What is the erythron?

Answer 2

The red blood cell ‘system’ in the bone marrow

Question 3

What 3 main substances are red blood cells broken down into by macrophages in the spleen?

Answer 3

Bilirubin
Iron
Amino Acids

Question 4

What causes an increase in erythropoietin?

Answer 4

Hypoxia

Question 5

What does an increase in erythropoietin cause?

Answer 5

Erythroid hyperplasia

Question 6

What is erythroid hyperplasia?

Answer 6

An increased count of erythroid precursors cells in the bone marrow
(due to increased levels of erythropoietin)

Question 7

What does -anaemia mean?

Answer 7

Lack of red cells / haemoglobin

Question 8

What does -cytosis or -philia mean?

Answer 8

An excess of

Question 9

What does -penia mean?

Answer 9

A shortage of

Question 10

What 3 things occur as normoblasts develop?

Answer 10

Accumulate Hb

Reduce in cell and nuclear size as the nucleus matures

Stop dividing and lose nucleus (Hb content triggers this)

Question 11

What is Megaloblastic anaemias characterised by?

Answer 11

Lack of red cells due to predominant defects in DNA synthesis and nuclear maturation in developing precursor cells in the marrow

Question 12

What does larger precursor cells with an immature nucleus leading to macrocytic anaemia imply?

Answer 12

Megaloblastic anaemia

Question 13

Name the two types of causes of macrocytic anaemia?

Answer 13

Genuine (true)

Spurious (false)

Question 14

What are the two subtypes of Genuine (true) causes of macrocytic anaemia?

Answer 14

Megaloblastic

Non-megaloblastic

Question 15

What are the causes of megaloblastic macrocytic anaemia?

Answer 15

B12 deficiency
Folate deficiency
Drugs
Rare inherited abnormalities

Question 16

What are the causes of non-megaloblastic macrocytic anaemia? Use LAHM

Which of them may not be associated with anaemia?

Answer 16

Alcohol
Liver disease
Hypothyroidism
Marrow failure

Alcohol, liver disease and hypothyroidism are not always associated with anaemia

Question 17

What does Macro- mean?

Answer 17

Big

Question 18

What does -cytosis mean?

Answer 18

An increase in cell numbers

Question 19

What is Spurious anaemia characterised by?

Answer 19

The volume of the mature red cell is NORMAL but the MCV is measured as high

Question 20

What is the main cause of spurious anaemia?

Answer 20

Reticulocytosis

Question 21

Patients with pernicious anaemia can present with what seemingly ‘odd’ symptom?

Answer 21

Jaundice

Question 22

What is Ineffective erythropoiesis?

Answer 22

When red cells die prematurely in the marrow

Haemoglobin and lactate dehydrogenase (LDH) are released from dead red cells

Haemoglobin converted to bilirubin

Question 23

What does pancytopenia do in patients with megaloblastic anaemia?

Answer 23

Pancytopenia complicates megaloblastic anaemia

Question 24

What can Nuclear maturation defects do?

Answer 24

Nuclear maturation defects can affect multiple lineages

Question 25

What is macrocytic anaemia?

Answer 25

Anaemia in which the red cells have a larger than normal volume

Question 26

What is MCV?

Answer 26

Mean Corpuscular Volume

Question 27

What is the importance of B12 and folate?

Answer 27

B12 and folate are essential co-factors in some linked biochemical reactions that regulate certain processes

Question 28

What linked biochemical reactions are regulated by co-factors B12 and folate?

Answer 28

DNA synthesis and nuclear maturation DNA modification, gene activity

Question 29

Why are B12 and folate important for DNA synthesis and nuclear maturation?

Answer 29

They allow for the conversion of uracil to thymine - if this is impaired there are no longer enough nucleotides to incorporate into DNA snythesis

Question 30

Where is B12 derived from?

Answer 30

Mainly meat and animal produce - meat and eggs are good sources

Question 31

What happens to B12 in the stomach?

Answer 31

B12 dissociates from food in the stomach, salivary proteins (Haptocorrin) protects B12 from the stomach acid

Question 32

What happens to B12 in the small intestine?

Answer 32

B12 and Haptocorrin combined travel through the jejunum and duodenum to the ileum where it meets intrinsic factor which absorbs the B12 into the small bowel to enter blood vessels

Question 33

What is pernicious anaemia?

Answer 33

Autoimmune condition with resulting destruction of gastric parietal cells

Question 34

What does pernicious anaemia result in?

Answer 34

Intrinsic factor deficiency with B12 malabsorption and deficiency

Question 35

Name some common causes of folate deficiency?

Answer 35

Inadequate intake Malabsorption Haemolysis Pregnancy Malignancy Drugs - anticonvulsants

Question 36

What is folate derived from?

Answer 36

Liver and leafy greens

Question 37

Where is B12 absorbed in the body?

Answer 37

The ileum

Question 38

Where is folate absorbed in the body?

Answer 38

The jejunum and duodenum

Question 39

What are the common clinical features of B12 and folate deficiency?

Answer 39

Symptoms / signs of anaemia weight loss, diarrhoea, infertility Sore tongue, jaundice Developmental problems

Question 40

What is seen in a blood film of a patient who has B12 / folate deficiency?

Answer 40

Blood film shows macrovalocytes and ‘hypersegmented’ neutrophils

Question 41

What is the flaw of anti gastric-parietal cell (GPC) antibodies?

Answer 41

FLAW - sensitive, not specific

Question 42

What is the flaw of anti-intrinsic factor (IF) antibodies?

Answer 42

FLAW – specific, not sensitive

Question 43

What is reticulocytosis?

Answer 43

An increase in reticulocyte numbers occurs as a marrow response to acute blood loss or red cell breakdown (haemolysis)

Question 44

What is the treatment option for pernicious anaemia?

Answer 44

Intramuscular B12 injections for life

Question 45

Where is B12 absorbed?

Answer 45

Terminal ileum

Question 46

Where is folate absorbed?

Answer 46

Jejunum

Question 47

Where is iron absorbed?

Answer 47

Duodenum and proximal jejunum

Question 48

How is excessive alcohol linked to folate deficiency?

Answer 48

Alcohol typically in place of food or patient more likely to not eat adequately - low dietary intake of folic acid

Question 49

What are common neurological symptoms of B12 deficiency?

Answer 49

Peripheral neuropathy - numbness and paraesthesia Loss of vibration sense Loss of proprioception

Question 50

What should be done in an adult who has no clear underlying cause of iron deficiency?

Answer 50

Colonoscopy Oesophagastroduodenoscopy