Haematology - Iron Deficiency Anaemia Flashcards
What can cause iron stores to be used up?
Dietary insufficiency
Loss of iron, heavy menstruation
Inadequate absorption e.g. Crohn’s
Where is iron absorbed?
Duodenum and jejunum
Why do PPIs interfere with iron absorption?
Stomach acid required to keep iron in soluble ferrous form (Fe2+)
With less acid, changes to insoluble ferric form (Fe3+)
What does transferrin do?
Carrier protein
Moves ferric ions in the blood
What is total iron binding capacity? (TIBC)
Total space on transferrin molecules for iron to bind
Directly related to amount of transferring in the blood
How do you calculate the proportion of transferring bound to iron?
Serum iron / total iron binding capacity
What is ferritin?
Form iron takes when it is deposited and stored in cells
What can happen to ferritin with inflammation?
Ferritin is released from cells when there is inflammation e.g. due to infection or cancer
What does low ferritin indicate?
Iron deficiency
Why is high ferritin difficult to interpret?
Likely to be inflammation related rather than iron overload
If ferritin levels are normal what does this indicate?
Can be normal but can still have an iron deficiency anaemia
Why is serum iron not a useful measure?
Varies significantly throughout the day
Higher in the morning and after eating iron rich foods
What blood test is easier to perform and is more widely used than transferring?
Total iron binding capacity
What happens to total iron binding capacity and transferring levels in iron deficiency and overload?
Increase in deficiency
Decrease in overload
What is a normal transferrin saturation?
30%
