Anaemia and microcytic anaemias

Question 1

what is anaemia

Answer 1

reduced total red cell mass

Question 1

steady state anaemia adult male

Answer 1

Hb <130g/L
Hct <0.38

Question 2

steady state anaemia adult female
(Hb and Hct)

Answer 2

Hb <120g/L
Hct <0.37

Question 3

normal Hb male

Answer 3

130-180g/L

Question 4

normal Hb female

Answer 4

120-160g/L

Question 5

how can we measure Hb concentration
(4 step process)

Answer 5

1. Burst the red cells to create Hb solution
2. Stabilise the Hb molecules
3. Measure the optical density at 540nm
4. then basically measure the redness
   the redder it is the more Hb

Question 6

how do we measure Haematocrit

Answer 6

Ratio (or commonly expressed as the percentage) of the whole blood that is red cells if the sample was left to settle
Modern machines calculate this by adding up the volume of the red cells it counts (if we know the number and size of cells it can work it out)

Question 7

when are Hb or Hct NOT good markers of anaemia?

Answer 7

1. acute trauma
2. patient has been given lots of fluids - Hb can be falsely low

Question 8

are reticulocytes smaller or larger than average red cells?

Answer 8

larger

Question 9

why do reticulocytes stain purple and not red?

Answer 9

still have some RNA which stains blue

Question 10

what does the MCV tell us

Answer 10

average size of the red cells

Question 11

pathophysiological classification of anaemia

Answer 11

decreased production (low reticulocyte count)

increased destruction (high reticulocyte count)

Question 12

anaemia - decreased production types

Answer 12

• hypoproliferative anaemia
• maturation defect (failure to produce Hb or failure of cell division)

Question 13

anaemia - increased destruction types

Answer 13

• blood loss
• haemolysis (premature red cell destruction)

Question 14

in increased destruction anaemia will the reticulocyte count be high or low

Answer 14

high because trying to replace

Question 15

MCV low - what type of anaemia

Answer 15

microcytic

Question 16

MCV high - what type of anaemia?

Answer 16

macrocytic

Question 17

If MCV low (microcytic) consider problems with __________

Answer 17

haemoglobinisation

Question 18

If MCV high (macrocytic) consider problems with __________

Answer 18

cell division ie maturation

Question 19

does haemoglobin synthesis occur in the nucleus or the cytoplasm of red cell precursors?

Answer 19

cytoplasm

Question 20

what do you need to make Hb

Answer 20

Available iron, porphyrin ring, globins (alpha and beta)

Question 21

microcytic anaemia - what’s going on

Answer 21

missing one of the elements needed to make haemoglobin: Available iron, porphyrin ring, globins (alpha and beta)

nucleus machinery is intact so cells keep dividing
One of the signals to stop dividing is Hb accumulation
This is delayed
As a result more cell divisions occur and the cells are smaller (microcytic)‏

• too many divisions, progeny get smaller, not as much Hb in them

Question 22

is microcytic anaemia a problem with the nucleus or cytoplasm?

Answer 22

cytoplasm

Question 23

commonest cause of microcytic anaemia

Answer 23

iron deficiency

Question 24

causes of hypochromic microcytic anaemias

Answer 24

haem deficiency - lack of iron for erythropoiesis - problems with porphyrin synthesis globin deficiency - Thalassaemia (trait, intermedia, major)

Question 25

iron is potentially toxic, true or false

Answer 25

true - so always chaperoned! always stuck to another protein in the body - transferrin or ferritin

Question 26

where is the majority of our iron

Answer 26

in our blood cells

Question 27

how much iron do we lose a day

Answer 27

1mg/day (small amount) just from skin shedding and stuff idk

Question 28

what is iron bound to in the transport system

Answer 28

transferrin

Question 29

iron is stored in ______ mainly in the _______

Answer 29

ferritin liver

Question 30

what is used to assess storage iron status

Answer 30

serum ferritin

Question 31

how many binding sites for iron does transferrin have

Answer 31

2

Question 32

what is transferrin role in transporting iron

Answer 32

Transports iron from donor tissues (macrophages, intestinal cells and hepatocytes) to tissues expressing transferrin receptors (especially erythroid marrow)

Question 33

what is ferritin

Answer 33

large intracellular protein can store loadsss of iron

Question 34

what does low ferritin mean

Answer 34

iron deficiency (because we don't make lots of ferritin if we don't have lots of iron to store)

Question 35

iron deficiency can be confirmed by a combination of _________ (decreased functional iron) and reduced _______ _____ (low serum ferritin)

Answer 35

anaemia storage iron

Question 36

Sequential consequences of negative iron balance

Answer 36

1. Exhaustion of iron stores (ferritin falls) 2. Iron deficient erythropoiesis then starts (MCV starts to fall) 3. Anaemia then develops 4. Epithelial changes (late effects in other sites of the chronic lack of iron) -skin -koilonychia -angular chelitis

Question 37

causes of iron deficiency (3 points)

Answer 37

- insufficient dietary iron (rare) - losing iron - usually blood loss (GI, menstrual, urinary) - malabsorption e.g. coeliac

Question 38

where is iron absorbed

Answer 38

proximal small bowel

Question 39

causes of chronic blood loss

Answer 39

Menorrhagia Gastrointestinal -Tumours -Ulcers -Non-steroidal anti-inflammatory agents Haematuria

Question 40

A small volume gastrointestinal blood loss can occur without any symptoms or signs of bleeding. 5mls of blood a day would be ____mg iron and might go unnoticed

Answer 40

2.5

Question 41

oral iron side effects

Answer 41

Mainly GI and related to elemental iron load on the gut Constipation, nausea, vomiting, abdo pains, dark stools This can result in poor compliance

Question 42

oral iron side effects are dose dependent, true or false

Answer 42

true - more you give, more side effects

Question 43

daily dose of iron that is sufficient for anaemia

Answer 43

65mg

Question 44

what is sodium feredetate (sytron)

Answer 44

liquid prep of iron, used in paediatrics

Question 45

when would parenteral (IV) iron be used instead of oral?

Answer 45

Poor tolerance of oral iron Poor compliance with oral iron Malabsorption issues (rare) Specific situations (eg renal anaemia)

Question 46

when giving iron for anaemia, how long after starting treatment do we assess response?

Answer 46

4-6 weeks (FBC)

Question 47

iron treatment for anaemia - typically need to continue for how long to replenish?

Answer 47

couple of months when you're back to normal

Question 48

Sequential consequences of negative iron balance

Answer 48

1. Exhaustion of iron stores (ferritin falls) 2. Iron deficient erythropoiesis (MCV falls) 3. Microcytic anaemia develops 4. Epithelial changes (effects elsewhere) - skin, koilonychia, angular chelitis