Blunted increase in serum hepcidin as response to oral iron in HFE-hemochromatosis

HFE hemochromatosis (HFE-H) is the most common and well-defined inherited cause for iron-related morbidity and mortality. Majority of patients with HFE-H are homozygote for C282Y mutation. Recent studies suggest that iron accumulation in most types of hemochromatosis is due to deficiency of hepcidin, a central iron regulator. However, the precise link between hepcidin levels and iron absorption in HFE-H patients has been poorly understood.

To measure hepcidin response to oral iron challenge (200 mg ferrous sulphate), in HFE-H (C282Y/C282Y) patients and compare with healthy controls (HCs).

Nine patients with C282Y/C282Y HFE-H along with 15 HC were recruited for the study. All HFE-H were iron depleted and studied at a time distant to phlebotomy. Hepcidin was measured using a published immunoassay method after ingestion of 65 mg oral iron challenge. Serum iron, ferritin and transferrin saturation were measured using standard methods. The area under the curve was calculated and compared between the two groups.

The basal serum hepcidin levels in patients with HFE-H were significantly low as compared with HC (P=0.0002). Incremental serum hepcidin response seen in HC reached significance at 4 h post iron challenge (P=0.0085) returning to baseline only at 24 h. There was no significant hepcidin response in HFE-H at 4 h (P=0.294). The overall hepcidin response was significantly lower in HFE-H compared with HC (area under the curve: P=0.0127).

Failure to mount a rapid hepcidin response to an oral iron challenge is the key mechanisms of iron accumulation despite prevailing excess body iron in patients with HFE-H with C282Y/C282Y mutation.