9: Approach to anaemia diagnosis

Question 1

What is anaemia?

Answer 1

Reduction in Hb concentration

i.e a lack of red blood cells

Question 2

Anaemia can be defined as having a Hb concentration of <__% population average.

Answer 2

< 95%

Question 3

In what physiological states can a person’s Hb concentraiton decrease?

Answer 3

Childhood growth

Pregnancy

Menstruation

Question 4

Apart from a full blood count, what other investigations exist for anaemia?

Answer 4

Reticulocyte count

Blood film

Vit B12 / Folate / Iron levels

Bone marrow biopsy

Question 5

In which causes of anaemia is reticulocyte count raised?

Answer 5

Blood loss

Haemolytic anaemias

Question 6

If reticulocyte count is raised, how would you tell the difference between anaemia caused by blood loss or haemolysis?

Answer 6

Breakdown products raised in haemolysis, not blood loss

so check serum bilirubin, iron

Question 7

What causes hypochromic microcytic anaemia?

Answer 7

iron deficiency

thalassaemia

lead poisoning

congenital sideroblastic anaemia

Question 8

What are some causes of macrocytic anaemia?

Answer 8

Megaloblastic - Vit B12 / folate deficiency; myelodysplasia

Non-megaloblastic - alcohol, liver disease, hypothyroidism

Question 9

What are two causes of spurious macrocytosis?

Answer 9

Reticulocytosis

Cold agglutinins

Question 10

What are some causes of normocytic anaemia?

Answer 10

Bone marrow failure

Malignancy

Renal impairment

Chronic disease

Question 11

What is renal anaemia?

Answer 11

Anaemia caused by impaired kidney function i.e an inability to produce EPO

Question 12

If the kidneys are damaged, which hormone will they struggle to produce?

What type of anaemia does this cause?

Answer 12

EPO

Hypoproliferative normocytic anaemia

Question 13

___ disease can cause a normocytic anaemia.

Answer 13

Renal disease

Chronic disease

Question 14

Which protein, released by the liver, inhibits iron exit from enterocytes?

Answer 14

Hepcidin

Question 15

What can cause increased production of hepcidin leading to a lack of iron in the circulation?

Answer 15

Inflammation in chronic disease

Question 16

In chronic disease, the ___ released during the inflammatory response can cause changes leading to anaemia.

Answer 16

cytokines

Question 17

What happens to

a) iron availability
b) EPO production
c) bone marrow proliferation

in chronic disease?

Answer 17

a) Iron availability decreases

b) EPO production decreases

c) Bone marrow proliferation decreases

Question 18

What type of anaemia does chronic disease cause?

Answer 18

Either normocytic due to hypoproliferation of RBCs

Or microcytic due to less available iron

Question 19

Why do some patients with anaemia of chronic disease respond to iron supplementation?

Answer 19

Not all patients have anaemia due to less available iron

Chronic disease also causes hypoproliferative anaemia so iron might not be the problem

Question 20

Is MCV absolutely or relatively low in microcytic anaemia?

Answer 20

Relatively low

So may not be below reference range but that doesn’t mean the patient isn’t iron deficient

Question 21

What is the best measurement for diagnosing iron deficiency?

Answer 21

Serum ferritin

Question 22

What are the problems with using serum ferritin to diagnose iron deficiency?

Answer 22

Serum levels are only a representation of levels within liver

Ferritin is an acute phase protein which increases in inflammation

Question 23

What are some microscopic features of red blood cells in iron deficiency anaemia?

Answer 23

Target cells

Rod form / pencil cells

Question 24

What must you think about when reticulocyte count is raised?

Answer 24

Blood loss and/or haemolysis

Question 25

Why does reticulocytosis increase MCV without causing an actual macrocytic anaemia?

Answer 25

Reticulocytes are bigger than normal red cells

Question 26

What are some microscopic features of megaloblastic anaemia?

Answer 26

Megaovalocytes

Hypersegmented neutrophils