Outlines of Mechanisms of Anaemia

Question 1

Anaemia can be broadly caused by two mechanisms. What are they?

Answer 1

1. Reduced number of total RBCs in circulation

2. A decreased / dysfunctional amount of haemoglobin in RBCs

Question 2

The symptom of Glossitis is specific to which type of Anaemia?

Answer 2

Vitamin B12 deficiency anaemia

Question 3

The symptom of Koilinychia is specific to which type of Anaemia?

Answer 3

Iron deficient anaemia

Question 4

The symptom of dark urine, particularly in the morning, is specific to which type of Anaemia?

Answer 4

Haemolytic anaemia

Question 5

What is the primary site of erythropoiesis?

Answer 5

Bone marrow

Question 6

What is Pure Red Cell Aplasia and give two conditions which are underpinned by PRCA

Answer 6

PRCA primarily affects erythropoiesis, and examples include:

Diamond-Blackfan anaemia
Congenital Dyserythropoietic anaemia

Question 7

What is Pancytopenia? How is it caused?

Answer 7

Conditions affecting both RBCs and other cell lineages i.e. WBCs and platelets

Caused by chemical / genetic insult, leading to failure of HSCs to self renew

Question 8

Gold therapy for rheumatoid arthritis causes what sort of anaemia?

Answer 8

Aplastic anaemia

Question 9

Chloramphenicol causes anaemia how?

Answer 9

Induces complete bone marrow failure (rare)

Question 10

Iron deficient anaemia appears on a blood film, how?

Answer 10

Hypochromic (pale)

Microcytic (small)

Question 11

What is microcytic anaemia, and what are the five main causes? (TAILS)

Answer 11

> 80 fL
Thalassemia
Anaemia of chronic inflammation
Iron deficiency anaemia
Lead poisoning
Sideroblastic anaemia

Question 12

How is Sideroblastic anaemia caused?

Answer 12

Ineffective incorporation of iron into RBC precursorcells. Iron rich mitochondria which surround RBC nucleus of precursors as granules (Sideroblasts)

Question 13

RBC destruction usually occurs after how many days?

Answer 13

120 days

Question 14

What is haemolysis?

Answer 14

Destruction rate > Production rate of RBCs

Question 15

What are the extrinsic causes of Haemolytic Anaemia? 3 examples

Answer 15

1. Autoimmune haemolytic anaemia
2. Alloimmune haemolysis
3. Drug induced immune haemolytic anaemia

Question 16

Give two examples of drugs which can cause drug induced immune haemolytic anaemia?

Answer 16

Methyldopa

Penicillin

Question 17

Give an example of an alloimmune haemolysis condition

Answer 17

Haemolytic disease of new-born (HDN)

Question 18

Give 3 examples of intrinsic causes of Haemolytic Anaemia

Answer 18

Damage
Enzyme absence
Haemoglobiopathies

Question 19

Give two examples of Haemoglobinopathies which cause intrinsically induced haemolytic anaemia?

Answer 19

Beta thalassemia

Sickle cell anaemia

Question 20

A multipotential haematopoietic stem cell has two forms of cells it can become. What are they?

Answer 20

Common myeloid progenitor

Common lymphoid progenitor

Question 21

What is the previous stage of an Erythrocyte in Erythropoiesis?

Answer 21

Reticulocyte

Question 22

What two vitamin deficiencies can cause anaemia?

Answer 22

B12 / Folate deficiency

B6

Question 23

Why is B12 / Folate important for erythrocyte production?

Answer 23

Essential for DNA Synthesis

Question 24

What size is RBCs in normocyte anaemia?

Answer 24

80 - 100 fL

Question 25

What size is RBCs is macrocytic anaemia?

Answer 25

> 100 fL

Question 26

What is the first stage of haemoglobin synthesis?

Answer 26

Glycine + Succinyl CoA => delta-aminolaevulinic acid (via ALA Synthase)