Anaemia, Vit B12, Folate & Polycythaemia

Question 1

Define anaemia

Answer 1

Decrease in the amount of RBCs/Hb = blood loss, decreases prod, increased removal

Question 2

What are the symptoms and signs of anaemia?

Answer 2

Symptoms = tiredness, pallor, reduced exercise tolerance, angina, palpitations, devel of heart failure.

Signs = pallor, tachycardia, increases resp rate, epithelial changes

Question 3

What are the 3 causes of reduced erythropoiesis?

Answer 3

1) Empty bone marrow = unable to response to EPO.
2) Infiltrated marrow = cancer.
3) Lack of response to haemostatic loop = e.g. kidneys stop making EPO in disease

Question 4

What is dyserythropoiesis and its clinical examples?

Answer 4

Dysfunctional erythropoiesis

anaemia of chronic disease (ACD),

myelodysplastic syndromes (MDS): prod of abnormal marrow stem cells = macrocytic anaemia

Question 5

How does megaloblastic anaemia arise?

Answer 5

1) Vit B12 def = diet, intrinsic factor def, disease of ilium, transcobalamin def (delivers B12 to one marrow)
2) Folate def = diet, duodenum/jejunum disease, drugs

Question 6

How does B12/folate def present on a blood film?

Answer 6

Macrocytic RBCs, hypersegmented neutrophils

Question 7

What is pernious anaemia?

Answer 7

Autoimmune disease = attacking gastric parietal cells = low intrinsic factors = can’t bind B12 to absorb it

Question 8

Give clinical example of anaemia due to Hb synthesis errors

Answer 8

Thalassaemia, sickle cell disease

Question 9

Name some disorders in which RBCs membrane structure leads to anaemia

Answer 9

Hereditary spherocytosis, hereditary elliptocytosis, hereditary pyropoikilocytosis, hereditary stomatocytosis

Question 10

How can damage to RBCs be acquired?

Answer 10

Heart valves, vasculitis, DIC, burns, drowning causes osmotic change

Question 11

How can loss of RBCs cause anaemia?

Answer 11

Haemorrhage = lower the RBC count = injury, ulceration, excessive menstruation

Question 12

In what circumstance in the removal of RBC increased?

Answer 12

Haemolytic anaemia, either intravascular/extravascular (RES) – can be autoimmune

Question 13

What are the basic investigations to request when you suspect haemolytic anaemia

Answer 13

Increased reticulocytes, raised bilirubin, raised LDH

Question 14

How can anaemia be classified?

Answer 14

Mechanism, size (macro/normo/microcytic), presence/absence of reticulocytosis

Question 15

What is the significance of a reticulocyte?

Answer 15

Means that the bone marrow is functional

Question 16

In what circumstances do you see an overproduction of RBCs?

Answer 16

Physiological reaction or myeloproliferative neoplasms (essential thrombocythaemia, polycythaemia vera)

Question 17

Outline polycythaemia vera

Answer 17

High haematocrit OR raised RBC mass, Jak2 mutation present (= increased prolif + survival of haematopoietic precursors).

Causes = arterial/venous thrombosis, haemorrhage, pruritus, splenic discomfort, gout

Question 18

What is erythrocytosis?

Answer 18

Increased in [RBC]:

Relative = normal RBC mass, but decreased plasma vol.

Absolute = increased RBC mass

Question 19

How is polycythaemia vera managed?

Answer 19

Venesection, aspirin, drugs to reduce overprod of cells

Question 20

What is a sign of intravascular haemolysis?

Answer 20

Haemoglobinaemia

Question 21

What does a direct Coombs test measure?

Answer 21

Abs bound directly to the surface of RBCs

Question 22

What are the causes of microcytic anaemia?

Hint: TAILS

Answer 22

T: thalassaemia
A: anaemia of chronic disease
I: iron def anaemia
L: lead poisoning
S: sideroblastic anaemia

Question 23

Which cellular process is most affected by folic acid def?

Answer 23

DNA synthesis

Question 24

What is the best source of B12?

Answer 24

Foods of animal origin

Question 25

What is a schistocyte?

Answer 25

RBC fragment

Question 26

What is a physiological responce to anaemia?

Answer 26

Increase 2,3-bisphosphoglycerate

= promotes release of oxygen bound to Hb, thus enhancing ability of RBCs to release oxygen near tissues