Iron studies
Last modified: 10 August 2022, 7:11:06 PM AEST
Ferritin1 / 6
- most useful
- Low in IDA
- But also an APR (acute phase reactant)
- IDA diagnosis
- Ferritin < 30 mcg/L
- most sensitive and specific test for IDA
- Ferritin < 100
- IDA if
- inflammation (CRP > 5 mg/L)
- transferrin saturation < 20%
- IDA if
- Ferritin 100 - 300
- IDA if TS (Transferrin Saturation) < 20%
- Ferritin < 30 mcg/L
Transferrin2 / 6
- iron transport protein
- TIBC = total iron binding capacity
- Increased
- IDA
Transferrin saturation
- calculated
- Serum Fe / (Transferrin x 25)
Serum iron3 / 6
- least useful
- varies hour to hour
- varies hour to hour
Hepcidin4 / 6
- hepatic hormone
- acute phase reactant
- actions
- ⬇GIT iron absorption
- think Hepcid-IN-hibit
- iron trapping in macrophages
- ⬇GIT iron absorption
- increases iron storage
- high in inflammatory states
- acute phase reactant
- this is why PO iron is NOT effective in chronic inflammation = absorption will be inhibited
- this is why we get AOCD = chronic inflammation
- inhibits transport of Fe into plasma from hepatocytes / macrophages / enterocytes
- IDA / severe anaemia = low hepcidin = appropriate = to +GIT absorption
- AOCD / inflammation = high hepcidin = inappropriate, causing -GIT absorption and anaemia (but maybe diverting resources elsewhere)
Diagnosis5 / 6
| IDA | AOCD | Thalassaemia | |
|---|---|---|---|
| Ferritin | low | N / high | high |
| Transferrin | high | low | N |
| TS % | low | low | N |
| Hepcidin | low | high | N |