Iron studies

Alternative names, keywords

Iron, Fe, transferrin, transferrin saturation, TSAT

Samples required

● Clotted blood (gold cap, 5 mL tube). Smaller tubes are available for paediatric samples.

Ideally patient should be fasted. The concentration of iron in serum is dependent on ingestion of iron and is subject to circadian variations. Avoid haemolysis.

Samples received more than 8 hours after venepuncture are unsuitable for analysis.

Test indications

Investigation/ monitoring of iron overload (e.g. haemochromatosis, "bronze diabetes", unexplained ALT increase). For routine iron deficiency testing please use ferritin.

Factors affecting test performance/ results

Avoid haemolysis - haemoglobin-bound iron can cause artificially increased values.

In patients treated with iron supplements or metal-binding drugs, the drug-bound iron may not properly react in the test, resulting in artificially low values.

In the presence of high ferritin concentrations > 1200 μg/L the assumption that serum iron is almost completely bound to transferrin is not valid anymore. Therefore, such iron results should not be used to calculate total iron binding capacity (TIBC) or percent transferrin saturation (% SAT).

In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results in both iron and transferrin assays.

Results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Reference range

Iron: 5.83 - 34.5 µmol/L

Transferrin: 2.0 - 3.6 g/L

Transferrin saturation: 25 - 45%

Turnaround time

Same day

Enquiries

Biochemistry (Automation)