How do I interpret serum ferritin and transferrin saturation results in the context of diagnosing haemochromatosis?

Serum ferritin and transferrin saturation (TSAT) are key biochemical markers used to diagnose haemochromatosis. In the context of haemochromatosis, an elevated transferrin saturation above 45% is considered an early and sensitive indicator of iron overload, often preceding a rise in serum ferritin levels NICE CKS. Serum ferritin reflects total body iron stores but can be elevated in various inflammatory or liver conditions, so it must be interpreted cautiously alongside TSAT and clinical context NICE CKS.

Specifically, a combination of raised transferrin saturation (>45%) and elevated serum ferritin (typically >300 µg/L in men and >200 µg/L in women) strongly suggests iron overload consistent with haemochromatosis, warranting further genetic testing for HFE mutations and specialist referral NICE CKS. However, serum ferritin alone is not diagnostic because it is an acute phase reactant and can be elevated in other liver diseases, infections, or metabolic syndrome Bardou-Jacquet et al. 2022. Therefore, transferrin saturation is considered a more specific initial screening test for haemochromatosis European Association for the Study of the Liver 2022.

In summary, the interpretation should prioritise transferrin saturation as the primary screening tool, with serum ferritin used to assess iron overload severity and exclude other causes of hyperferritinaemia. Elevated TSAT (>45%) with raised ferritin supports haemochromatosis diagnosis, while discordant results require further evaluation to exclude alternative diagnoses Hsu et al. 2022.