Approach to diagnosing anaemia

Question 1

what is anaemia

Answer 1

reduction in Hb concentration for what is normal to that individual

Question 2

what tools can be used to diagnose anaemia

Answer 2

History and examination 
FBC
Blood film 
Reticulocytes 
Haematinics - B12/folate/ferritin
Bone marrow biopsy 
specialised tests eg HLPC in thalassaemia

Question 3

how can anaemia be classified according to bone marrow function

Answer 3

measure reticulocytes

Question 4

what does reticulocytosis in context of anaemia mean for bone marrow

Answer 4

bone marrow is active and trying to compensate for red cell loss or destruction

Question 5

what does a low reticulocyte count in context of anaemia mean for bone marrow

Answer 5

there is a defect in bone marrow and it cannot compensate

there is reduced red cell production

Question 6

what are causes of anaemia with reticulocytosis

Answer 6

haemorrhage

haemolysis

Question 7

how can you differentiate between haemolysis and haemorrhage

Answer 7

haemorrhage = reticulocytosis only 
haemolysis = reticulocytosis AND breakdown products

Question 8

what are the 2 main categories that cause anaemia with a low reticulocyte count

Answer 8

hypoproliferative

maturation abnormality

Question 9

what are causes of maturation abnormality in anaemia

Answer 9

cytoplasmic defect - impaired haemoglobinisation

nuclear defect - impaired DNA synthesis and nuclear maturation

Question 10

what size are cells with impaired haemoglobinisation

Answer 10

small/low MCV/microcytic

Question 11

what size are cells with impaired DNA synthesis

Answer 11

large/high MCV/macrocytic

Question 12

what size are cells that cause hypoproliferative anaemia

Answer 12

normocytic

Question 13

why are cells with impaired haemoglobinisation microcytic?

Answer 13

Because they cannot make Hb, they dont reach the threshold needed to trigger enucleation.
Therefore, the cells keep dividing meaning they keep getting smaller hence microcytic cells

Question 14

why are cells with impaired DNA synthesis macrocytic?

Answer 14

Cells have abnormal nuclei and so cell division is abnormal meaning there are fewer divisions resulting in fewer cells that are large. Failure to become smaller cells.

Question 15

if reticulocytes are low, what is the next step investigation

Answer 15

red cell indices: MCV, MCH

Question 16

what are causes of microcytic anaemia

Answer 16

insufficient Hb synthesis

Haem or globin

Question 17

causes of haem deficiency

Answer 17

Fe deficiency: diet, bleeding, malabsorption

Porphyrin deficiency: genetic

Question 18

causes of globin deficiency

Answer 18

Thalassaemias

alpha: trait, HbH, Hb Barts Hydrops fetalis
beta: trait, intermedia, major

Question 19

what are causes of macrocytosis

Answer 19

alcohol
liver disease
hypothyroidism

Question 20

what are causes of megaloblastic macrocytic anaemia

Answer 20

B12/folate deficiency
drugs
inherited

Question 21

causes of non-megaloblastic macrocytic anaemia

Answer 21

marrow failure:
myelodysplasia - mutation in stem cells
aplastic anaemia

Question 22

causes of spurious macrocytosis

Answer 22

reticulocytosis

cold agglutins

Question 23

causes of hypoproliferative normocytic anaemia

Answer 23

marrow failure 
hypometabolic
marrow infiltration 
renal impairment 
anaemia of chronic disease

Question 24

what is renal anaemia

Answer 24

anaemia of chronic disease due to failure of EPO production

Question 25

is there a single pathological mechanism for anaemia of chronic disease

Answer 25

no, multifactorial

Question 26

what is the central process behind anaemia of chronic disease

Answer 26

inflammation

Question 27

what are the mechanisms of anaemia of chronic disease

Answer 27

inflammation activates monocytes and T cells which produce pro inflammatory cytokines: - increased hepatic synthesis of hepcidin causes degradation of ferroportin and so iron is trapped - EPO production is reduced - erythroid proliferation in marrow is inhibited - haemophagocytosis by macrophages in induced

Question 28

anaemia of chronic disease can sometimes be microcytic, true or false

Answer 28

true | if the predominant mechanism is increased hepcidin

Question 29

``` what will the following results show in iron deficiency anaemia: serum iron transferrin % transferrin saturation ferritin MCV ```

Answer 29

``` serum iron - low transferrin - normal/low % transferrin saturation - low ferritin - low MCV - low (can be normal) ```

Question 30

``` what will the following results show in anaemia of chronic disease: serum iron transferrin % transferrin saturation ferritin MCV ```

Answer 30

``` serum iron - low transferrin - normal/low % transferrin saturation - low ferritin - high/normal MCV - normal (can be low) ```

Question 31

what are the steps to approaching anaemia in blood results

Answer 31

``` name, age, ethnicity, PC FBC - red cells, Hb, WBC, platelets Red cell indices - MCV, MCH Reticulocytes Blood film Haematinics Special tests / biopsy ```