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Flashcards in Iron Deficiency Anaemia Deck (50)
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1
Q

Ferrous

A

Fe2+

2
Q

Ferric

A

Fe3+

3
Q

Iron is absorbed at the

A

Duodenum

4
Q

Apical side of duodenum:

Duodenal cytochrome B (DcytB) function?

A

Reduces Fe3+ to Fe2+ at apical membrane of enterocytes

5
Q

Divalent metal transporter (DMT1) function on apical side of duodenum?

A

Transports non-haem Fe2+ across apical membrane

6
Q

Heme on apical side is from ?

A

Red meat

7
Q

Heme and ferritin is absorbed in duodenum’s apical side via?

A

Unknown transporters

8
Q

Enterocyte: Hemeoxydase1 (HO-1) function?

A

Removes Fe2+ from heme

9
Q

Basal side: ferroportin function?

A

Transports Fe2+ on basal side to plasma

10
Q

Basal side: hephaestin function?

A

Oxidizes Fe2+ to Fe3+ at basal membrane

11
Q

Basal side: transferrin function?

A

Transports iron in blood

12
Q

Iron donation to plasma: macrophage phagocytizes?

A

RBC

13
Q

Iron donation to plasma: ferroportin function?

A

Transports Fe2+ into blood

14
Q

Ceruloplasmin function in iron donation to plasma?

A

Oxidizes Fe2+ to Fe3+ in blood

15
Q

Iron donation to plasma: transferrin function?

A

Transferrin binds Fe3+

16
Q

Describe iron uptake by cells:

A
  1. Diferric transferrin endocytosed
  2. Acid pumped into endosome to remove Fe3+
  3. STREAP3 reduced Fe3+ to Fe2+
  4. DMT1 transfers Fe2+ into cytosol
  5. Transferrin released to plasma
17
Q

Regulation of iron metabolism is managed by?

A

Hepcidin

18
Q

Hepcidin is the?

A

Master controller of iron in body

19
Q

Hepcidin is produced and released by?

A

Liver

20
Q

How does liver detect iron-content of blood?

A

Liver has iron receptors that detect iron-content of blood

21
Q

Function of hepcidin?

A

Binds and internalizes ferroportin on enterocytes and macrophages.
- Inhibits iron release into blood

22
Q

List the three risk factors for iron deficiency

A
  1. Increase iron requirement
  2. Limited external iron supply
  3. Blood loss
23
Q

what can increase iron requirement?

A
  1. Growth

2. Erythropoiesis-stimulating treatment

24
Q

What can cause limited external iron supply?

A
  • Poor diet/intake

- Malabsorption

25
Q

What can cause blood loss?

A
  • Removal of blood (e.g. donation or dialysis)

- Haemorrhage

26
Q

Serum ferritin assay measures?

A

Measures amount of ferritin in blood; reflects total iron content

27
Q

Serum iron concentration measures?

A

Measure serum iron concentration by denaturing transferring and adding reducing agent and colorizing agent.

28
Q

Iron-binding capacity lab test measures?

A

Measures excess transferrin in serum

29
Q

List the steps in iron-binding capacity lab test

A
  • Measure iron content before (unsaturated iron-binding capacity (UIBC))
  • Add extra iron to serum to saturate transferrin
  • Wash away excess
  • Measure iron content after (Total iron-binding capacity (TIBC))
30
Q

Large difference in UIBC (unsaturated iron-binding capacity) and TIBC (total iron-binding capacity) means?

A

Iron deficiency anaemia (body makes excess transferrin when iron is low)

31
Q

Serum transferrin assay lab test

A

Directly measures amount of transferrin

32
Q

Transferrin saturation

A

Ratio of UIBC and TIBC

33
Q

Low levels of ferritin

A

iron deficiency

34
Q

High levels of ferritin

A

Iron overload

35
Q

Low levels of serum iron

A

Iron deficiency

36
Q

High levels of serum iron

A

Haemochromatosis (genetic disease that causes high iron absorption

37
Q

High levels of transferrin but low saturation

A

Iron deficiency, but saturation is low

38
Q

High levels of transferrin and high saturation

A

Iron overload

39
Q

High level of total iron binding capacity

A

Iron deficiency

40
Q

Ferritin is best indicator of?

A

Best indicator of body iron stores

41
Q

List lab studies/results for iron deficiency anaemia

A
  • Low Hb
  • Low transferrin saturation (<20%)
  • Low ferritin concentration
42
Q

RBC indices of iron deficiency anaemia

A
  • Low mean cell Hb concentration (i.e. hypochromasia - increased pale area of RBC) -> best indicator for irond eficiency
  • Use MCV for differential diagnosis
43
Q

Low mean cell Hb concentration

A

Best indicator for iron deficiency

44
Q

Blood films in iron deficiency anaemia: red cells

A
  • Hypochromia (pale cells)
  • Microcytosis (small cells)
  • Poikilocytosis (odd shape, e.g. “pencil cells”)
  • Target cells
  • Increased platelet count
45
Q

Hypochromia

A

Pale red blood cells

46
Q

Microcytosis

A

small red blood cells

47
Q

Poikilocytosis

A

Odd shaped red blood cells (pencil shaped cells)

48
Q

Thalassaemia Trait differential diagnosis

A

Low MCV but normal Hb production

49
Q

Anaemia of chronic disease differential diagnosis

A

Increased red cell stacking (rouleaux) and background staining (from Ig)

50
Q

Iron deficiency anaemia differential diagnosis

A

Anisochromasia (RBC shape and colour) and pencil cells