Iron studies require detailed interpretation.
The following figures on Iron Studies are taken from Melbourne haematology guidelines.
Serum iron; Considerable variation occurs within a day in individuals and assessment of serum iron alone provides little helpful clinical information. If initial serum iron is low I repeat the test to identify if low serum iron is a chronic or long standing event.
Serum transferrin (or total iron binding capacity; TIBC) / Transferrin saturation. Iron is bound to transferrin in the plasma. Total iron binding capacity (TIBC) is a direct measure of level of transferrin. Transferrin levels are reduced in inflammation.
(In my practice, I use this to have extra evidence of inflammation. )
The level of transferrin saturation is particularly helpful if assessment of early stages of iron overload with levels > 55% for males and > 50% for females indicative of iron overload (should be fasting level for more accurate assessment)
Serum ferritin: Small amount of circulating serum ferritin reflects body iron stores. Is now well established in assessment of iron stores, Normal range 15 – 300 ug/l (reference ranges vary depending on the method used). Levels < 15 ug/l reflect absent /reduced iron stores.
Elevated levels of serum Ferritin may reflect iron overload but will be increased in liver disease, inflammation or malignant disease. In the presence of inflammation, a level of > 100 ug/l generally excludes iron deficiency
In my practice, I look for iron deficiency and interpret iron overload as indicative of inflammation.-and, less commonly, in cases of first relatives diagnosed with haemachromatosis.