H1, H2: Anaemia

Question 1

Life span of RBC

Answer 1

120 days

Question 2

Where does RBC death occur

Answer 2

Spleen: in in reticuloendothelial system

Question 3

What is anaemia

Answer 3

Low Hb (not a diagnosis)

Question 4

What are the causes of anaemia

Answer 4

1. Reduced RBC production due to
   - iron deficiency
   - B12/folate deficiency
   - marrow infiltration e.g. cancer
   - chronic disease e.g. rheumatoid, cancer
2. Increased destruction of RBCs due to
   - haemolytic anaemia (disorders of RBC membrane, enzyme or Hb)
3. Loss of RBCs due to bleeding

Question 5

How is anaemia classified

Answer 5

1. Inherited vs. Acquired
2. Mactocytic/ Normocytic/ Mactocytic
3. Immune vs. Non-immune

Question 6

What are the causes of microcytic anaemia

Answer 6

1. Iron deficiency anaemia
2. Thalassaemia
3. Chronic disease

Question 7

What is iron deficiency anaemia

Answer 7

A cause of Microcytic anaemia = most common nutrient deficiency causing defective Hb synthesis meaning RBCs are small, pale, target and pencil cells containing low amounts of Hb (hypochromic)

Question 8

What are the causes of iron deficiency anaemia

Answer 8

(Iron deficiency ammonia is not a diagnosis itself)

1. Pre-menopausal females = Menorrhagia
2. Males/Post-menopausal females = GIT bleeding (ulcers, cancer, IBD)

Question 9

What is thalassaemia

Answer 9

A cause of microcytic anaemia = Autosomal dominant condition where a + B chains are synthesised at a slow rate

Question 10

What special investigations are carried out for microcytic anaemia

Answer 10

1. FBC
2. Blood film
3. Serum ferritin
4. Serum iron
5. Transferrin saturation

Question 11

What are the treatments for microcytic anaemia

Answer 11

Diet, oral iron intake, avoid blood transfusion

Question 12

What are the causes of normocytic anaemia

Answer 12

1. Acute blood loss
2. Chronic diseases
3. Cancer
4. Renal disease
5. Haemolysis

Question 13

How does chronic disease cause anaemia

Answer 13

It can cause either microcytic or normocytic anaemia due to chronic inflammation and infection

• There is a decreased RBC lifespan
• Poor marrow response to EPO meaning
• Decreased erythropoiesis
• Inflammatory cytokines interfere with EPO production

Question 14

How does cancer cause anaemia

Answer 14

It causes normocytic anaemia because there is marrow infiltration, metastatic cancer (breast, prostate, lung, thyroid ect.), myeloma, myelofibrosis, leukaemia, lymphoma

Question 15

Outline the clinical features of normocytic anaemia

Answer 15

• Loss of appetite
• Brittle nails
• Pale lips
• Sore mouth

Question 16

What special investigations are done for normocytic anaemia

Answer 16

Blood film is not useful
MCV is normal
Serum urin and TIBC = low
Ferritin = High

Question 17

What are the treatments for normocytic anaemia

Answer 17

• Investigate and manage underlying causes

- Erythropoietin hormone to stimulate RBC release

Question 18

What are the causes of macrocytic anaemia

Answer 18

1. Vitamin B12 deficiency
2. Folate deficiency
3. Haemolytic anaemia
4. Autoimmune haemolytic anaemia
5. Alcohol
6. Drugs
7. Liver disease
8. Bone marrow failure
9. Myelodysplasia
10. Haemolysis (if reticulocytosis)

Question 19

How does vitamin B12 and folate deficiency cause macrocytic anaemia

Answer 19

These are needed for DNA synthesis thus when lowered, cells fail to divide (delayed maturation of nucleus of erythroblast) and this causes large cells

Question 20

What can cause vitamin B12 deficiency anaemia

Answer 20

This is a macrocytic anaemia called Pernicious anaemia which is autoimmune (autoantibody to gastric mucosa and IF leading to poor B12 absorption)

Question 21

Why might vitamin B12 and folate deficiency anaemia occur

Answer 21

Due to

• Malabsorption : Coeliac / Crohn’s
• XS utilisation : Pregnancy, Lactation, Psoriasis
• Anticonvulsants, antifolate drugs

Question 22

What are the clinical features of deficiency state macrocytic anaemias

Answer 22

1. Insidious (fatal if untreated)
2. Glossitis
3. Mild jaundice
4. Neurology in B12 deficiency

B12 and folate deficiencies are clinically indistinguishable

Question 23

How are deficiency state macrocytic anaemias treated

Answer 23

B12
IM B12 injections every 3 months

Folate
Oral folic acid tablets

Question 24

What is haemolytic anaemia

Answer 24

A cause of macrocytic anaemia where the RBC lifespan <120 days due to abnormalities of

• Membrane due to autoantibodies/spherocytosis
• Hb due to thalassaemia or sickle cell anaemia
• Enzymes (G6P dehydrogenase deficiency = x-linked)

Question 25

What is hereditary spherocytosis

Answer 25

An autosomal dominant condition where RBCs are spherical so there is less HB and more LDH and unconjugated serum bilirubin - this is a cause of haemolytic anaemia (which causes macrocytic anaemia)

Question 26

What is sickle cell anaemia

Answer 26

Where there is a point mutation in the globin gene so when [O2] = low, long rod structures are formed (RBC sickles) and this increases rigidity so can block the microcirculation causing ischaemia and pain - this is a cause of haemolytic anaemia (which causes macrocytic anaemia)

Question 27

What are the clinical features of haemolytic anaemia

Answer 27

(This is a type of macrocytic anaemia)

• Neonatal jaundice
• Acute haemolysis with oxidant drugs and fava beans
• Pallor
• Splenomegaly
• Gallstones

Question 28

What are the causes of autoimmune haemolytic anaemia

Answer 28

Drugs, CT disease, cancer, blood transfusion:

There is self-reacting IgG antibody that binds to RBC which is then removed by spleen in extravascular haemolysis (this causes macrocytic anaemia)

Question 29

What investigations are done for autoimmune haemolytic anaemia

Answer 29

• History/examination
• Check serum B21, folate, ferritin
• Repeat FBC and blood film
• ESR
• Renal/liver function