Hepcidin and anaemia.

The anaemia of chronic disease (ACD) is a common haematologic syndrome characterized by hypoferraemia with adequate reticuloendothelial iron stores. Frequently, serum ferritin concentration in these patients is elevated. The pathogenesis of ACD involves abnormalities in red cell survival, the erythropoietic response to anaemia, and in iron metabolism. Hepcidin is an antibacterial protein produced in the liver which can be found in blood or urine, and which participates in host defense. Recent studies have demonstrated that hepcidin is a key regulator of iron balance in the intestinal mucosa, and that abnormalities in hepcidin gene expression are associated with clinical abnormalities in iron parameters and, in some cases, with anaemia. Hepcidin is an acute-phase reacting protein, and it has been suggested that hepcidin is the key mediator of ACD. Investigation of hepcidin production in either serum or urine demonstrates a strong correlation with serum ferritin concentration. Differences between the hepcidin concentrations observed in ACD (or syndromes resembling ACD) and those observed in iron deficiency may depend on the definition used for the anaemia syndrome. It seems very likely that hepcidin is a major contributor to iron abnormalities characteristic of ACD; whether it contributes to the pathogenesis of the syndrome in a broader sense remains to be determined by further investigation.