Anaemia introduction

Question 1

Anaemia is defined as

Answer 1

the condition in which your body has insufficient red blood cells (RBCs) or haemoglobin to meet its needs.

Question 2

why does anaemia cause disease?

Answer 2

Without the correct levels, your body is unable to carry enough oxygen to its cells for them to carry out their normal function

Question 3

clinical definition of anaemia

Answer 3

haemoglobin level that is below 130g/L for males and below 120g/L for females.

Question 4

Anaemia is not standalone diagnosis, but a

Answer 4

sign of underlying pathology.

Question 5

How does anaemia occur?

Answer 5

Anaemia can take place due to a variety of disruptions to the life cycle of a RBC

Question 6

lifecycle of an RBC

Answer 6

3 stages

1) Production in bone marrow
2) Circulation- peripheral RBC
3) Destruction - reticuloendothelial system

Question 7

disruption to RBC that can occur during production (2)

Answer 7

1) Dyserythropoiesis

2) Defects in haemoglobin synthesis (haemoglobinopathies)

Question 8

Dyserythropoiesis is the

Answer 8

development of defective RBC

Question 9

Dyserythropoiesis causes

Answer 9

congenital

inherited

acquired

Question 10

difference between congenital and inherited disorders

Answer 10

Congenital disorders are present from birth, and hereditary disorders are transmitted from parents to their children through the genes.

Question 11

give an example of inherited Dyserythropoiesis

Answer 11

congenital dyserythropoietic anaemia (CDA)

Question 12

give an example of acquired Dyserythropoiesis

Answer 12

1) Bone marrow is unable to produce enough RBCs. This can be due to damaged bone marrow from chemotherapy drugs or infection.
2) Another cause of acquired dyserythropoiesis is chronic disease and inflammation, which in itself has a variety of causes ranging from renal disease (reduced erythropoietin) to rheumatoid arthritis (this increases the uptake of iron into cells and reduces the amount available for RBC production).

Question 13

give the two major causes of defective production of haemoglobin

Answer 13

1) Deficiency in essential substances

2) Mutation in proteins that form the global chain of Hb

Question 14

deficiency in which essential substances can cause defective production of haemoglobin

Answer 14

iron, vitamin B12 and folate.

Question 15

why can vitamin B12 and folate deficiency cause anaemia

Answer 15

These are essential building blocks in the production of haemoglobin, so any deficiency in these leads to a lower RBC production.

Question 16

name 2 diseases which cause anaemia due to mutations int he proteins that forms he globing chains of Hb

Answer 16

Thalassaemia

Sickle cell disease

Question 17

thalassaemia and sickle cell disease come under a branch called

Answer 17

Haemoglobinopathies

Question 18

disruption to RBC that can occur during circulation (2)

Answer 18

1) damage to red cells- haemolytic anaemias

2) excessive bleeding

Question 19

what is Haemolysis

Answer 19

abnormal damage to RBCs

Question 20

where can Haemolysis occur

Answer 20

in the blood vessels themselves (intravascular haemolysis), or in the spleen (extravascular haemolysis)

Question 21

a large majority of RBC are damaged due to…

Answer 21

shear stress

Question 22

shear stress

Answer 22

a form of mechanical damage to the cells when they are forced through small gaps in vessels or valves, for example due to damaged heart valves, vasculitis or disseminated intravascular coagulopathies.

Question 23

In a blood film how would RBC appear if they have been damaged by shear stress

Answer 23

as schistocytes

Question 24

other acquired forms of haemolytic anaemia

Answer 24

heat damage and osmotic changes can cause changes in the structure of RBC

Question 25

name some inherited conditions which cause RBC damage in circulation

Answer 25

hereditary spherocytosis (spectrum defect)

glucose-6-phosphate dehydrogenase deficiency

pyruvate kinase deficiency

Question 26

glucose-6-phosphate dehydrogenase deficiency and pyruvate kinase deficiency cause

Answer 26

increased RBC breakdown

Question 27

the body can also attack its own RBC- this is called

Answer 27

autoimmune haemolytic anaemia

Question 28

autoimmune hameolytic anaemia

Answer 28

Autoantibodies produced by your immune system bind to the proteins on the RBC membrane, causing the RBCs to be targeted and destroyed

Question 29

what diseases can case targeted destruction of RBCS

Answer 29

lupus, lymphomas, certain viruses like EBV/HIV) and some types of medications (e.g. penicillin).

Question 30

where are RBC damaged in the periphery removed from circulation

Answer 30

red pulp of the spleen

Question 31

why can damage to RBC in the periphery cause anaemia

Answer 31

the spleen removes these damaged RBC- when this happens repeatedly the bone marrow struggles to keep up with the body’s requirements as RBCs are often destroyed faster than they can be replaced.

Question 32

How can excessive bleeding (in injury, surgery or childbirth) cause anaemia

Answer 32

When there is a large loss of blood, there is a reduced level of iron in the body, so the bone marrow is unable to increase the production of new cells to replace those that were lost.

Question 33

common cause of excessive bleeding that causes anaemia

Answer 33

menorrhagia

Question 34

menorrhagia

Answer 34

heavy blood loss during menstruation

Question 35

disruption to RBC that can occur during destruction

Answer 35

removal by the Reticuloendothelial System (RES)

Question 36

Reticuloendothelial System (RES)

Answer 36

removes damaged RBC from the circulation

Question 37

why can the Reticuloendothelial System (RES) cause anaemia

Answer 37

become an issue when RBCs are destroyed faster than they can be replaced.

Question 38

an overactive RES

Answer 38

An overactive RES speeds up the process of red cell destruction, and can be seen in hypersplenism.